Name: analysis of scap n-glycosylation and trafficking in human cells
Uploaded: 2016-11-08T14:00:00.000+00:00
Duration: 11 min 27 s
Description: Watch this Scientific Journal Video about Analysis of SCAP N-glycosylation and Trafficking in Human Cells at JoVE.com

We are grateful to Drs. Mike S. Brown and Joseph L. Goldstein for their agreement to publish this method according to the methods described in their publications. We appreciate Dr. Peter Espenshade for sharing the GFP-SCAP plasmid. This work was supported by NIH grants NS072838 and NS079701 to D.G., American Cancer Society Research Scholar Grant RSG-14-228-01-CSM to D.G., and OSUCCC Pelotonia Postdoctoral Fellowship to C.C. We also appreciate the support from the Ohio State Neuroscience Core (P30 NS038526) and OSUCCC Translational Therapeutic Program seed grant and start-up funds to D.G.

1.内源性的检测SCAP蛋白在人类细胞中<ol><li>细胞培养和治疗<ol><li>在10cm皿用Dulbecco补充有5％胎牛血清（FBS）的改良Eagle培养基（DMEM）种子〜1×10 6个 U87细胞和孵育所述细胞在37℃和5％CO 2的处理前24小时。 </li><li>用磷酸盐缓冲盐水（PBS）洗一次细胞，然后切换细胞新鲜DMEM培养基有或没有葡萄糖（5毫米）12小时。 </li></ol></li><li>细胞膜组份和核提取物的制备<ol><li>洗涤细胞一次，用PBS，刮成1ml的PBS，并离心在1000 xg离心在4℃下5分钟。 </li><li>悬浮细胞在含有10mM HEPES-KOH（pH值7.6），10mM的氯化钾，1.5mM的MgCl 2的，1毫钠乙二胺四乙酸（EDTA），1mM的乙烯钠乙二醇四乙酸（EGTA），250毫冰冷的缓冲蔗糖，和蛋白酶抑制剂的混合物（5μ微克/毫升胃酶抑素A，10μg/ ml的亮肽素，0.5mM的苯甲基磺酰氟（PMSF），1mM的二硫苏糖醇（DTT），和25微克/毫升的N-乙酰基亮氨酸 - 亮氨酸 - 正Leu-人（ALLN））30分钟在冰上。 </li><li>通过一个22国祥通过细胞提取物1 1/2针30倍和离心机在890 xg离心在4℃下5分钟，以分离细胞核。 </li><li>使用上清液用于膜级分（步骤1.2.7）的分离。重悬核沉淀在0.1的缓冲液C（20mM的HEPES / KOH pH 7.6中，0.42 M氯化钠，2.5％（体积/体积）甘油的溶液，1.5毫的MgCl 2，1mM的EDTA钠，1mM的钠EGTA和的混合物蛋白酶抑制剂（5微克/毫升胃酶抑素A，10μg/ ml的亮肽素，0.5mM的PMSF，1毫摩尔DTT，和25微克/毫升ALLN））。 </li><li>在4℃下旋转，在4℃进行60分钟，并离心悬浮液以20,000 xg离心在微量20分钟。上清液被指定为"核提取物"。 </li><li>加热在100℃下的核提取物10分钟，用5×上样缓冲液（312.5毫的Tris-HCl pH 6.8的，10％的SDS，50％甘油，12.5％β巯基乙醇和0.05％溴酚蓝）经受SDS-PAGE之前。 </li><li>离心从原来的890 XG自旋上清液以20,000 xg离心在4℃下20分钟。用于随后的免疫印迹分析，溶解沉淀在0.1ml SDS裂解缓冲液（10mM的Tris-HCl pH 6.8的，100毫摩尔NaCl，1％（V / V）十二烷基硫酸钠（SDS），1mM的EDTA钠和1毫EGTA钠）。这被指定为"膜部分"。 注意:我们用20000×g离心20分钟以沉淀膜。 100000×g离心10 - 20分钟已经从Brown和戈尔茨坦实验室15的文件被使用。 </li><li>孵育膜级分在37℃下30分钟，并确定由Bradford蛋白测定蛋白质浓度。对样品进行SDS-PAGE前，加入1μl100X溴酚蓝的解决方案。 </li><li>负载25 -总膜蛋白质的50微克在10％SDS-PAGE凝胶39。运行凝胶在80伏15分钟，然后换到130 V和再运行115分钟。转移在140毫安130分钟39。 <ol><li>对于Western印迹分析，使用抗SCAP抗体检测总蛋白SCAP。使用蛋白质二硫键异构酶（PDI），一个ER驻留蛋白40，作为内部对照。使用抗SREBP-1抗体来检测SREBP-1的N末端带。使用拉明A作为内部控制的核提取物31。 </li></ol></li></ol></li></ol> 2. SCAP分析ň-glycosylation在人类细胞<ol><li>细胞培养，转染，和治疗<ol><li>用于膜分析，在10cm皿用DMEM种子〜1×10 6个 HEK293T细胞补充有5％FBS和孵育在37℃下将细胞与5％CO 2的转染前24小时。 </li><li>稀释4 - 8微克GFP-SCAP质粒（彼得Espenshade博士的礼物）22在1毫升降低血清培养基，轻轻混匀。 </li><li>通过直接吹打成1ml的降低含质粒的血清的培养基16微升DNA转染试剂，轻轻混匀 - 添加8。 </li><li>孵育转染试剂/质粒复合物，在室温下25分钟。 </li><li>添加转染复合物与新鲜培养基中的细胞，并继续培养在5％CO 2和37℃24小时。 </li><li>用PBS洗一次并具有或不具有在衣霉素（1微克/毫升） 中，N -glycosylation抑制剂的存在或不存在葡萄糖（5毫摩）处理细胞12小时。 </li></ol></li><li>在步骤1.2.1，1.2.2，1.2.3，1.2.7和介绍准备细胞膜颗粒。 </li><li> SCAPñ-glycosylation检测<ol><li>胰蛋白酶蛋白水解<ol><li>从细胞中114微升含有10mM HEPES·KOH（pH 7.4）中，10毫米氯化钾，1.5mM的MgCl 2的，1毫钠EDTA和100mM NaCl的缓冲液中过表达的GFP-SCAP重悬膜粒料。 </li><li> 57孵育81;在无或1微升胰蛋白酶（1微克/微升）存在膜蛋白质的等分试样，在58微升在30℃下的总体积，为30分钟。 </li><li>通过加入大豆胰蛋白酶抑制剂的2微升（400单位）停止反应。 </li></ol></li><li>通过肽N-糖苷酶F去糖基化（PNG酶F） <ol><li>用于与酶F随后的治疗中，添加10微升含3.5％（重量/体积）SDS和7％（体积/体积）溶液2-巯基乙醇至每个样品。 </li><li>在100℃下加热10分钟后，按顺序添加的0.5M磷酸钠（pH 7.5），7微升10％（V / V）的Nonidet P-40的12×蛋白酶抑制剂，和2微升的7微升（0.5单位PNG酶F的/微升） </li><li>在37℃下3小时温育后，通过加入5×上样缓冲液（312.5毫的Tris-HCl pH 6.8的，10％的SDS，50％甘油，12.5％β巯基乙醇和0.05％溴酚蓝）的停止反应。加热在100℃下的混合物为10米在并受到SDS-PAGE。负载25-50在10％SDS-PAGE凝胶39总的膜蛋白的微克。在运行80伏的凝胶15分钟，然后换到130 V代表另一个115分钟。转移在140毫安130分钟。 </li><li>对于Western印迹，使用10μg/ ml的抗SCAP（9D5）抗体来检测Ñ-glycosylation和总SCAP蛋白。 </li></ol></li></ol></li></ol> 3.从ER到高尔基贩运SCAP检测由人体细胞用GFP-SCAP <ol><li>在60毫米培养皿用DMEM种子2.5×10 5个 U87细胞补充有5％FBS和孵育在37℃下将细胞与5％CO 2的转染前24小时。 </li><li>稀释0.5ml的4微克GFP-SCAP质粒降低血清培养基混合。 </li><li>吹打直接进入0.5毫升含质粒的降低血清中添加8微升DNA转染试剂，轻轻混匀。 </li><li>孵育转染试剂/质粒复合物，在室温25分钟温度。 </li><li>添加转染复合物与新鲜培养基中的细胞，并继续培养在5％CO 2和37℃24小时。 </li><li>补种5 - 10×10 4个细胞到含玻璃盖玻片（22毫米×22毫米）6孔板，并继续培养，在37℃和5％CO 2的24小时。 </li><li>用PBS洗一次并具有或不具有在衣霉素（1微克/毫升）的存在或不存在葡萄糖（5毫摩）处理细胞12小时。 </li><li>用PBS洗涤细胞一次，并在4％的甲醛固定10分钟。 </li><li>洗涤细胞三次，用PBS，反转盖玻片，在幻灯片上与抗淬灭剂一起安装，并且使用指甲油密封盖玻片。 </li><li>检查激光扫描共聚焦显微镜41使用63X油浸物镜的GFP-SCAP贩卖。 </li></ol>

<ol>
	<li>Ru, P., Williams, T. M., Chakravarti, A., Guo, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor+metabolism+of+malignant+gliomas.">Tumor metabolism of malignant gliomas.</a> Cancers (Basel). 5, 1469-1484 (2013).</li><li>Moon, Y. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Scap/SREBP+pathway+is+essential+for+developing+diabetic+fatty+liver+and+carbohydrate-induced+hypertriglyceridemia+in+animals.">The Scap/SREBP pathway is essential for developing diabetic fatty liver and carbohydrate-induced hypertriglyceridemia in animals.</a> Cell metabolism. 15, 240-246 (2012).</li><li>Guo, D., Bell, E. H., Chakravarti, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lipid+metabolism+emerges+as+a+promising+target+for+malignant+glioma+therapy.">Lipid metabolism emerges as a promising target for malignant glioma therapy.</a> CNS Oncology. 2, 289-299 (2013).</li><li>Guo, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+AMPK+agonist+AICAR+inhibits+the+growth+of+EGFRvIII-expressing+glioblastomas+by+inhibiting+lipogenesis.">The AMPK agonist AICAR inhibits the growth of EGFRvIII-expressing glioblastomas by inhibiting lipogenesis.</a> Proceedings of the National Academy of Sciences of the United States of America. , 12932-12937 (2009).</li><li>Menendez, J. A., Lupu, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fatty+acid+synthase+and+the+lipogenic+phenotype+in+cancer+pathogenesis.">Fatty acid synthase and the lipogenic phenotype in cancer pathogenesis.</a> Nat Rev Cancer. 7, 763-777 (2007).</li><li>Guo, D., Cloughesy, T. F., Radu, C. G., Mischel, P. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=AMPK:+A+metabolic+checkpoint+that+regulates+the+growth+of+EGFR+activated+glioblastomas.">AMPK: A metabolic checkpoint that regulates the growth of EGFR activated glioblastomas.</a> Cell Cycle. 9, 211-212 (2010).</li><li>Goldstein, J. L., DeBose-Boyd, R. A., Brown, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protein+sensors+for+membrane+sterols.">Protein sensors for membrane sterols.</a> Cell. 124, 35-46 (2006).</li><li>Shao, W., Espenshade, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expanding+Roles+for+SREBP+in+Metabolism.">Expanding Roles for SREBP in Metabolism.</a> Cell metabolism. 16, 414-419 (2012).</li><li>Nohturfft, A., Zhang, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coordination+of+lipid+metabolism+in+membrane+biogenesis.">Coordination of lipid metabolism in membrane biogenesis.</a> Annual review of cell and developmental biology. 25, 539-566 (2009).</li><li>Jeon, T. I., Osborne, T. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SREBPs:+metabolic+integrators+in+physiology+and+metabolism.">SREBPs: metabolic integrators in physiology and metabolism.</a> Trends in endocrinology and metabolism: TEM. 23, 65-72 (2012).</li><li>Sato, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assignment+of+the+membrane+attachment,+DNA+binding,+and+transcriptional+activation+domains+of+sterol+regulatory+element-binding+protein-1+(SREBP-1).">Assignment of the membrane attachment, DNA binding, and transcriptional activation domains of sterol regulatory element-binding protein-1 (SREBP-1).</a> The Journal of biological chemistry. 269, 17267-17273 (1994).</li><li>Sakai, J., Nohturfft, A., Goldstein, J. L., Brown, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cleavage+of+sterol+regulatory+element-binding+proteins+(SREBPs)+at+site-1+requires+interaction+with+SREBP+cleavage-activating+protein.+Evidence+from+in+vivo+competition+studies.">Cleavage of sterol regulatory element-binding proteins (SREBPs) at site-1 requires interaction with SREBP cleavage-activating protein. Evidence from in vivo competition studies.</a> The Journal of biological chemistry. 273, 5785-5793 (1998).</li><li>Sakai, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+complexes+between+the+COOH-terminal+domains+of+sterol+regulatory+element-binding+proteins+(SREBPs)+and+SREBP+cleavage-activating+protein.">Identification of complexes between the COOH-terminal domains of sterol regulatory element-binding proteins (SREBPs) and SREBP cleavage-activating protein.</a> The Journal of biological chemistry. 272, 20213-20221 (1997).</li><li>Hua, X., Nohturfft, A., Goldstein, J. L., Brown, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sterol+resistance+in+CHO+cells+traced+to+point+mutation+in+SREBP+cleavage-activating+protein.">Sterol resistance in CHO cells traced to point mutation in SREBP cleavage-activating protein.</a> Cell. 87, 415-426 (1996).</li><li>Nohturfft, A., Brown, M. S., Goldstein, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Topology+of+SREBP+cleavage-activating+protein,+a+polytopic+membrane+protein+with+a+sterol-sensing+domain.">Topology of SREBP cleavage-activating protein, a polytopic membrane protein with a sterol-sensing domain.</a> The Journal of biological chemistry. 273, 17243-17250 (1998).</li><li>Nohturfft, A., Hua, X., Brown, M. S., Goldstein, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recurrent+G-to-A+substitution+in+a+single+codon+of+SREBP+cleavage-activating+protein+causes+sterol+resistance+in+three+mutant+Chinese+hamster+ovary+cell+lines.">Recurrent G-to-A substitution in a single codon of SREBP cleavage-activating protein causes sterol resistance in three mutant Chinese hamster ovary cell lines.</a> Proc Natl Acad Sci U S A. 93, 13709-13714 (1996).</li><li>Espenshade, P. J., Hughes, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+sterol+synthesis+in+eukaryotes.">Regulation of sterol synthesis in eukaryotes.</a> Annu Rev Genet. 41, 401-427 (2007).</li><li>Yang, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Crucial+step+in+cholesterol+homeostasis:+sterols+promote+binding+of+SCAP+to+INSIG-1,+a+membrane+protein+that+facilitates+retention+of+SREBPs+in+ER.">Crucial step in cholesterol homeostasis: sterols promote binding of SCAP to INSIG-1, a membrane protein that facilitates retention of SREBPs in ER.</a> Cell. 110, 489-500 (2002).</li><li>Yabe, D., Brown, M. S., Goldstein, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Insig-2,+a+second+endoplasmic+reticulum+protein+that+binds+SCAP+and+blocks+export+of+sterol+regulatory+element-binding+proteins.">Insig-2, a second endoplasmic reticulum protein that binds SCAP and blocks export of sterol regulatory element-binding proteins.</a> Proc Natl Acad Sci U S A. 99, 12753-12758 (2002).</li><li>Yabe, D., Xia, Z. P., Adams, C. M., Rawson, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three+mutations+in+sterol-sensing+domain+of+SCAP+block+interaction+with+insig+and+render+SREBP+cleavage+insensitive+to+sterols.">Three mutations in sterol-sensing domain of SCAP block interaction with insig and render SREBP cleavage insensitive to sterols.</a> Proc Natl Acad Sci U S A. 99, 16672-16677 (2002).</li><li>Espenshade, P. J., Li, W. P., Yabe, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sterols+block+binding+of+COPII+proteins+to+SCAP,+thereby+controlling+SCAP+sorting+in+ER.">Sterols block binding of COPII proteins to SCAP, thereby controlling SCAP sorting in ER.</a> Proceedings of the National Academy of Sciences of the United States of America. 99, 11694-11699 (2002).</li><li>Nohturfft, A., Yabe, D., Goldstein, J. L., Brown, M. S., Espenshade, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulated+step+in+cholesterol+feedback+localized+to+budding+of+SCAP+from+ER+membranes.">Regulated step in cholesterol feedback localized to budding of SCAP from ER membranes.</a> Cell. 102, 315-323 (2000).</li><li>Sakai, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sterol-regulated+release+of+SREBP-2+from+cell+membranes+requires+two+sequential+cleavages,+one+within+a+transmembrane+segment.">Sterol-regulated release of SREBP-2 from cell membranes requires two sequential cleavages, one within a transmembrane segment.</a> Cell. 85, 1037-1046 (1996).</li><li>Wang, X., Sato, R., Brown, M. S., Hua, X., Goldstein, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SREBP-1,+a+membrane-bound+transcription+factor+released+by+sterol-regulated+proteolysis.">SREBP-1, a membrane-bound transcription factor released by sterol-regulated proteolysis.</a> Cell. 77, 53-62 (1994).</li><li>Brown, M. S., Goldstein, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+proteolytic+pathway+that+controls+the+cholesterol+content+of+membranes,+cells,+and+blood.">A proteolytic pathway that controls the cholesterol content of membranes, cells, and blood.</a> Proceedings of the National Academy of Sciences of the United States of America. 96, 11041-11048 (1999).</li><li>Rawson, R. B., DeBose-Boyd, R., Goldstein, J. L., Brown, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Failure+to+cleave+sterol+regulatory+element-binding+proteins+(SREBPs)+causes+cholesterol+auxotrophy+in+Chinese+hamster+ovary+cells+with+genetic+absence+of+SREBP+cleavage-activating+protein.">Failure to cleave sterol regulatory element-binding proteins (SREBPs) causes cholesterol auxotrophy in Chinese hamster ovary cells with genetic absence of SREBP cleavage-activating protein.</a> J Biol Chem. 274, 28549-28556 (1999).</li><li>Zelenski, N. G., Rawson, R. B., Brown, M. S., Goldstein, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Membrane+topology+of+S2P,+a+protein+required+for+intramembranous+cleavage+of+sterol+regulatory+element-binding+proteins.">Membrane topology of S2P, a protein required for intramembranous cleavage of sterol regulatory element-binding proteins.</a> J Biol Chem. 274, 21973-21980 (1999).</li><li>Goldstein, J. L., Brown, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Century+of+Cholesterol+and+Coronaries:+From+Plaques+to+Genes+to+Statins.">A Century of Cholesterol and Coronaries: From Plaques to Genes to Statins.</a> Cell. 161, 161-172 (2015).</li><li>Espenshade, P. J., Cheng, D., Goldstein, J. L., Brown, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autocatalytic+processing+of+site-1+protease+removes+propeptide+and+permits+cleavage+of+sterol+regulatory+element-binding+proteins.">Autocatalytic processing of site-1 protease removes propeptide and permits cleavage of sterol regulatory element-binding proteins.</a> The Journal of biological chemistry. 274, 22795-22804 (1999).</li><li>Guo, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SCAP+links+glucose+to+lipid+metabolism+in+cancer+cells.">SCAP links glucose to lipid metabolism in cancer cells.</a> Mol Cell Oncol. 3, (2016).</li><li>Cheng, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glucose-Mediated+N-glycosylation+of+SCAP+Is+Essential+for+SREBP-1+Activation+and+Tumor+Growth.">Glucose-Mediated N-glycosylation of SCAP Is Essential for SREBP-1 Activation and Tumor Growth.</a> Cancer Cell. 28, 569-581 (2015).</li><li>Shao, W., Espenshade, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sugar+Makes+Fat+by+Talking+to+SCAP.">Sugar Makes Fat by Talking to SCAP.</a> Cancer Cell. 28, 548-549 (2015).</li><li>Guo, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=EGFR+signaling+through+an+Akt-SREBP-1-dependent,+rapamycin-resistant+pathway+sensitizes+glioblastomas+to+antilipogenic+therapy.">EGFR signaling through an Akt-SREBP-1-dependent, rapamycin-resistant pathway sensitizes glioblastomas to antilipogenic therapy.</a> Sci Signal. 2, 82 (2009).</li><li>Guo, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+LXR+agonist+promotes+GBM+cell+death+through+inhibition+of+an+EGFR/AKT/SREBP-1/LDLR-dependent+pathway.">An LXR agonist promotes GBM cell death through inhibition of an EGFR/AKT/SREBP-1/LDLR-dependent pathway.</a> Cancer Discov. 1, 442-456 (2011).</li><li>Guo, D., Bell, E. H., Mischel, P., Chakravarti, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Targeting+SREBP-1-driven+lipid+metabolism+to+treat+cancer.">Targeting SREBP-1-driven lipid metabolism to treat cancer.</a> Curr Pharm Des. 20, 2619-2626 (2014).</li><li>Bell, E. H., Guo, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomarkers+for+malignant+gliomas.">Biomarkers for malignant gliomas.</a> Malignant Gliomas, Radiation Medicine Rounds. 3, 339-357 (2012).</li><li>Geng, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inhibition+of+SOAT1+suppresses+glioblastoma+growth+via+blocking+SREBP-1-mediated+lipogenesis.">Inhibition of SOAT1 suppresses glioblastoma growth via blocking SREBP-1-mediated lipogenesis.</a> Clin Cancer Res. , (2016).</li><li>Ru, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Feedback+Loop+Regulation+of+SCAP/SREBP-1+by+miR-29+Modulates+EGFR+Signaling-Driven+Glioblastoma+Growth.">Feedback Loop Regulation of SCAP/SREBP-1 by miR-29 Modulates EGFR Signaling-Driven Glioblastoma Growth.</a> Cell Rep. , (2016).</li><li>Green, M. R., Sambrook, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Molecular Cloning: A Laboratory Manual (Fourth Edition). , (2012).</li><li>Uehara, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=S-nitrosylated+protein-disulphide+isomerase+links+protein+misfolding+to+neurodegeneration.">S-nitrosylated protein-disulphide isomerase links protein misfolding to neurodegeneration.</a> Nature. 441, 513-517 (2006).</li><li>Miyashita, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Confocal+microscopy+for+intracellular+co-localization+of+proteins.">Confocal microscopy for intracellular co-localization of proteins.</a> Methods Mol Biol. 1278, 515-526 (2015).</li><li>Cao, J., Guo, S., Arai, K., Lo, E. H., Ning, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studying+extracellular+signaling+utilizing+a+glycoproteomic+approach:+lectin+blot+surveys,+a+first+and+important+step.">Studying extracellular signaling utilizing a glycoproteomic approach: lectin blot surveys, a first and important step.</a> Methods Mol Biol. 1013, 227-233 (2013).</li></ol>

The authors have nothing to disclose.

在这项研究中，我们描述了在人细胞中膜部分的分离和用于通过使用免疫印迹制备样品用于检测SCAPÑ-glycosylation和总蛋白的一个协议。我们还提供采用GFP标记和共聚焦显微镜监测SCAP贩卖的方法。该方法是专门用于分析膜蛋白是研究SCAPñ-glycosylation和贩卖人口的重要工具。 使用各种凝集素识别不同氮肥 -glycan链，并确定ñ糖基蛋白42的方法相比?...

脂质代谢的失调是癌症和代谢性疾病1-6的一个共同特点。在这些方法中，固醇调节元件结合蛋白（SREBPs），一个家族的转录因子，在控制基因的摄取和胆固醇，脂肪酸的合成，和磷脂7-10重要的表达中起关键作用。 SREBPs，包括SREBP-1a中，SREBP-1c和SREBP-2，合成为凭借两个跨膜结构域7的结合于内质网（ER）膜活性的前体。 SREBPs的N-末端包含靶基因11的转录的DNA结合结构域。 SREBP前体的C末端结合至SREBP裂解激活蛋白（SCAP）12,13，即起着SREBP稳定性和活化14-16的调节中发挥关键作用一个多面体膜蛋白。 该implemen转录功能的塔季翁需要从ER到高尔基体，其中两个蛋白酶顺序裂解SREBP并释放其N-末端片段，然后进入细胞核为生脂基因7的反式激活的SCAP / SREBP复合物的转运。在这些过程中，甾醇的在ER膜的水平从ER 7,17控制SCAP / SREBP复合物的出口。下高固醇的条件下，固醇结合SCAP或ER驻留胰岛素诱导的基因蛋白-1（INSIG-1）或-2（INSIG-2），从而增强与保留SCAP / SREBP复杂的Insigs SCAP的关联ER 18-20。当固醇水平降低，SCAP解离与Insigs。这导致了SCAP构象变化，这允许具有共同的外壳蛋白（COP）的二复杂SCAP相互作用。复合介导SCAP / SREBP复合物的掺入出芽囊泡和从ER到高尔基体21,22指示其传输。当transloc通货膨胀到高尔基体，SREBPs依次由站点1和站点2蛋白酶裂解，导致N末端7,23-29的释放。 SCAP蛋白携带三个N天冬酰胺-连接低聚糖（N）位置N263，N590，N641和15。最近，我们发现，在这些网站SCAP的葡萄糖介导ñ-glycosylation是从低固醇条件下30-32内质网向高尔基SCAP / SREBP贩卖的先决条件。通过以谷氨酰胺（NNN到QQQ）所有三个天冬酰胺的突变SCAP糖基化的损失禁用SCAP / SREBP复杂并且导致SCAP蛋白和减少SREBP活化31的不稳定的贩卖。我们最近的数据还表明，SREBP-1在胶质母细胞瘤是高度激活和SCAPñ-glycosylation 4,31,33,34调节。针对SCAP / SREBP-1信号正在成为一个新的战略来治疗恶性肿瘤和代谢小号yndromes 1,3,35-38。因此，开发以分析SCAP蛋白和N -glycosylation水平和监测其在人类细胞和患者组织贩卖一种有效的方法是重要的。 SCAP蛋白质（氨基酸540-707）在ER腔区域包含了保护，当蛋白水解胎膜与胰蛋白酶处理15两个N -glycosylation网站（N590和N641）。这个管腔片段的分子量〜30kDa的的足够小，以允许通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE）15,31的SCAP的个别糖基化变体的分辨率。这里，我们提供了用于检测SCAP 氮 -glycosylation和人类细胞中的总蛋白的方法。此协议是从由布朗和戈尔茨坦实验室15和我们最近出版31出版物中描述的方法的。该协议可以在T使用他从哺乳动物细胞SCAP蛋白的研究。

<table><tbody><tr><td>X-treme GENE HP DNA Transfection Reagent</td><td>Roche</td><td>6366236001</td><td></td></tr><tr><td>Opti-MEMI medium</td><td>Life Technologies</td><td>31985-070</td><td></td></tr><tr><td>trypsin&amp;nbsp;</td><td>Sigma</td><td>T6567</td><td></td></tr><tr><td>soybean trypsin inhibitor</td><td>Sigma</td><td>T9777</td><td></td></tr><tr><td>PNGase F&amp;nbsp;</td><td>Sigma</td><td>P7367</td><td></td></tr><tr><td>Anti-SCAP (9D5) antibody&amp;nbsp;&amp;nbsp;</td><td>Santa Cruz</td><td>sc-13553</td><td></td></tr><tr><td>GFP antibody&amp;nbsp;</td><td>Roche</td><td>11814460001</td><td></td></tr><tr><td>SREBP-1 antibody (IgG-2A4)</td><td>BD Pharmingen</td><td>557036</td><td></td></tr><tr><td>PDI Antibody (H-17)</td><td>Santa Cruz</td><td>sc-30932</td><td></td></tr><tr><td>Lamin A Antibody (H-102)</td><td>Santa Cruz</td><td>sc-20680</td><td></td></tr><tr><td>SCAP antibody (a.a 450-500)</td><td>Bethyl Laboratories, Inc.</td><td>A303-554A</td><td></td></tr><tr><td>Dulbecco&amp;rsquo;s modified Eagle&amp;rsquo;s medium (DMEM) without glucose, pyruvate and glutamine&amp;nbsp;&amp;nbsp;</td><td>Cellgro</td><td>17-207-CV</td><td>Add 1 mM Pyravate and 4 mM Glutamine before use</td></tr><tr><td>22 G x 1 1/2 needle</td><td>BD</td><td>305156</td><td></td></tr><tr><td>pepstatin A</td><td>Sigma</td><td>P5318</td><td></td></tr><tr><td>leupeptin</td><td>Sigma</td><td>L2884</td><td></td></tr><tr><td>PMSF</td><td>Sigma</td><td>P7626</td><td></td></tr><tr><td>DTT</td><td>Sigma</td><td>43819</td><td></td></tr><tr><td>ALLN</td><td>Sigma</td><td>A6185</td><td></td></tr><tr><td>Nitrocellulose membrane</td><td>GE</td><td>RPN3032D</td><td></td></tr><tr><td>EDTA Solution 0.5 M pH 8.5 100 ml</td><td>VWR</td><td>82023-102</td><td></td></tr><tr><td>EGTA 0.5 M sterile (pH 8.0) 50 ml</td><td>Fisher Scentific</td><td>50255956</td><td></td></tr><tr><td>HyClone FBS</td><td>Thermo scientific</td><td>SH3007103</td><td></td></tr><tr><td>glycerol</td><td>Sigma</td><td>G5516</td><td></td></tr><tr><td>&amp;beta;-mercaptoethanol&amp;nbsp;</td><td>Sigma</td><td>M3148</td><td></td></tr><tr><td>bromophenol blue</td><td>Sigma</td><td>B8026</td><td></td></tr><tr><td>prolong gold antifade reagent with dapi</td><td>Life Technologies</td><td>P36935</td><td></td></tr><tr><td>L-glutamine (200 mM)</td><td>Life Technologies</td><td>25030081</td><td></td></tr><tr><td>sodium pyruvate</td><td>Life Technologies</td><td>11360-070</td><td></td></tr></tbody></table>

analysis of scap n-glycosylation and trafficking in human cells

Elevated lipogenesis is a common characteristic of cancer and metabolic diseases. Sterol regulatory element-binding proteins (SREBPs), a family of membrane-bound transcription factors controlling the expression of genes important for the synthesis of cholesterol, fatty acids and phospholipids, are frequently upregulated in these diseases. In the process of SREBP nuclear translocation, SREBP-cleavage activating protein (SCAP) plays a central role in the trafficking of SREBP from the endoplasmic reticulum (ER) to the Golgi and in subsequent proteolysis activation. Recently, we uncovered that glucose-mediated N-glycosylation of SCAP is a prerequisite condition for the exit of SCAP/SREBP from the ER and movement to the Golgi. N-glycosylation stabilizes SCAP and directs SCAP/SREBP trafficking. Here, we describe a protocol for the isolation of membrane fractions in human cells and for the preparation of the samples for the detection of SCAP N-glycosylation and total protein by using western blot. We further provide a method to monitor SCAP trafficking by using confocal microscopy. This protocol is appropriate for the investigation of SCAP N-glycosylation and trafficking in mammalian cells.

图1示出了响应于人脑胶质瘤U87细胞内源性SCAP蛋白和SREBP-1的核形式的检测通过使用免疫印迹对葡萄糖刺激。膜蛋白SCAP在"膜部分"检测的。 SREBP-1的核形式（N末端）中的"核提取物"被检测。 SCAP蛋白的水平（PDI作为ER膜蛋白内部对照）和SREBP-1的核形式由葡萄糖刺激都显着增强。这些结果表明，该协议能够检测在人类细胞中的内源性SCAP蛋白。 <p class="jove_con...

Watch this Scientific Journal Video about Analysis of SCAP N-glycosylation and Trafficking in Human Cells at JoVE.com

Analysis of SCAP N-glycosylation and Trafficking in Human Cells

我们通过使用蛋白质印迹描述了从人类细胞的膜级分的分离和样品制备用于检测SCAPÑ-glycosylation和总蛋白的改进方法。我们还引进了GFP标记法使用共聚焦显微镜监测SCAP贩卖。这种协议可以在常规生物学实验室使用。

SCAP分析<em&gt;ñ</em&gt; -glycosylation和贩卖人体细胞

Elevated lipogenesis is a common characteristic of cancer and metabolic diseases. Sterol regulatory element-binding proteins (SREBPs), a family of ...

analysis-of-scap-n-glycosylation-and-trafficking-in-human-cells

Universidad de Cartagena UDEC

Research

JoVE Journal

Biology

Analysis of SCAP N-glycosylation and Trafficking in Human Cells

8.6K 次观看.  The Ohio State University Comprehensive Cancer Center and College of Medicine. 我们通过使用蛋白质印迹描述了从人类细胞的膜级分的分离和样品制备用于检测SCAPÑ-glycosylation和总蛋白的改进方法。我们还引进了GFP标记法使用共聚焦显微镜监测SCAP贩卖。这种协议可以在常规生物学实验室使用。 

视频: Analysis of SCAP N-glycosylation and Trafficking in Human Cells

Glycan Node Analysis: A Bottom-up Approach to Glycomics

Synthesized in a non-template-driven process by enzymes called glycosyltransferases, glycans are key players in various significant intra- and extracellular events. Many pathological conditions, notably cancer, affect gene expression, which can in turn deregulate the relative abundance and activity levels of glycoside hydrolase and glycosyltransferase enzymes. Unique aberrant whole glycans resulting from deregulated glycosyltransferase(s) are often present in trace quantities within complex biofluids, making their detection difficult and sometimes stochastic. However, with proper sample preparation, one of the oldest forms of mass spectrometry (gas chromatography-mass spectrometry, GC-MS) can routinely detect the collection of branch-point and linkage-specific monosaccharides ("glycan nodes") present in complex biofluids. Complementary to traditional top-down glycomics techniques, the approach discussed herein involves the collection and condensation of each constituent glycan node in a sample into a single independent analytical signal, which provides detailed structural and quantitative information about changes to the glycome as a whole and reveals potentially deregulated glycosyltransferases. Improvements to the permethylation and subsequent liquid/liquid extraction stages provided herein enhance reproducibility and overall yield by facilitating minimal exposure of permethylated glycans to alkaline aqueous conditions. Modifications to the acetylation stage further increase the extent of reaction and overall yield. Despite their reproducibility, the overall yields of N-acetylhexosamine (HexNAc) partially permethylated alditol acetates (PMAAs) are shown to be inherently lower than their expected theoretical value relative to hexose PMAAs. Calculating the ratio of the area under the extracted ion chromatogram (XIC) for each individual hexose PMAA (or HexNAc PMAA) to the sum of such XIC areas for all hexoses (or HexNAcs) provides a new normalization method that facilitates relative quantification of individual glycan nodes in a sample. Although presently constrained in terms of its absolute limits of detection, this method expedites the analysis of clinical biofluids and shows considerable promise as a complementary approach to traditional top-down glycomics.

This article presents an enhanced form of a novel bottom-up glycomics technique designed to analyze the pooled compositional profile of glycans in unfractionated biofluids through the chemical breakdown of glycans into their constituent linkage-specific monosaccharides for detection by GC-MS. Potential applications include early detection of cancer and other glycan-affective disorders.

聚糖节点分析:自下而上的方法，以糖原组学

Synthesized in a non-template-driven process by enzymes called glycosyltransferases, glycans are key players in various significant intra- and ...

科研

化学

Characterization of Glycoproteins with the Immunoglobulin Fold by X-Ray Crystallography and Biophysical Techniques

Glycoproteins on the surface of cells play critical roles in cellular function, including signalling, adhesion and transport. On leukocytes, several of these glycoproteins possess immunoglobulin (Ig) folds and are central to immune recognition and regulation. Here, we present a platform for the design, expression and biophysical characterization of the extracellular domain of human B cell receptor CD22. We propose that these approaches are broadly applicable to the characterization of mammalian glycoprotein ectodomains containing Ig domains. Two suspension human embryonic kidney (HEK) cell lines, HEK293F and HEK293S, are used to express glycoproteins harbouring complex and high-mannose glycans, respectively. These recombinant glycoproteins with different glycoforms allow investigating the effect of glycan size and composition on ligand binding. We discuss protocols for studying the kinetics and thermodynamics of glycoprotein binding to biologically relevant ligands and therapeutic antibody candidates. Recombinant glycoproteins produced in HEK293S cells are amenable to crystallization due to glycan homogeneity, reduced flexibility and susceptibility to endoglycosidase H treatment. We present methods for soaking glycoprotein crystals with heavy atoms and small molecules for phase determination and analysis of ligand binding, respectively. The experimental protocols discussed here hold promise for the characterization of mammalian glycoproteins to give insight into their function and investigate the mechanism of action of therapeutics.

We present approaches for the biophysical and structural characterization of glycoproteins with the immunoglobulin fold by biolayer interferometry, isothermal titration calorimetry, and X-ray crystallography.

用 X 射线晶体学和生物物理技术表征免疫球蛋白折叠的糖蛋白

Glycoproteins on the surface of cells play critical roles in cellular function, including signalling, adhesion and transport. On leukocytes, several of ...

生物化学

Analysis of Endocytic Uptake and Retrograde Transport to the Trans-Golgi Network Using Functionalized Nanobodies in Cultured Cells

Transport of proteins and membranes from the cell surface to the Golgi and beyond is essential for homeostasis, organelle identity and physiology. To study retrograde protein traffic, we have recently developed a versatile nanobody-based toolkit to analyze transport from the cell surface to the Golgi complex, either by fixed and live cell imaging, by electron microscopy, or biochemically. We engineered functionalized anti-green fluorescent protein (GFP) nanobodies &#8212; small, monomeric, high-affinity protein binders &#8212; that can be applied to cell lines expressing membrane proteins of interest with an extracellular GFP moiety. Derivatized nanobodies bound to the GFP reporters are specifically internalized and transported piggyback along the reporters&#39; sorting routes. Nanobodies were functionalized with fluorophores to follow retrograde transport by fluorescence microscopy and live imaging, with ascorbate peroxidase 2 (APEX2) to investigate the ultrastructural localization of reporter-nanobody complexes by electron microscopy, and with tyrosine sulfation (TS) motifs to assess kinetics of trans-Golgi network (TGN) arrival. In this methodological article, we outline the general procedure to bacterially express and purify functionalized nanobodies. We illustrate the powerful use of our tool using the mCherry- and TS-modified nanobodies to analyze endocytic uptake and TGN arrival of cargo proteins.

Retrograde transport of proteins from the cell surface to the Golgi is essential to maintain membrane homeostasis. Here, we describe a method to biochemically analyze cell surface-to-Golgi transport of recombinant proteins using functionalized nanobodies in HeLa cells.

培养细胞功能化纳米化对跨 golgi 网络的内分泌吸收和逆行迁移分析

Transport of proteins and membranes from the cell surface to the Golgi and beyond is essential for homeostasis, organelle identity and physiology. To ...

N-glycan Profiling of Glycoproteins by Hydrophilic Interaction Liquid Chromatography with Fluorescence and Mass Spectrometric Detection

Glycosylation is a vital modification found in proteins. N-glycan profiling of glycoproteins is required to detect novel biomarker candidates and determine glycan alterations in diseases. Most commercially available biopharmaceutical proteins are glycoproteins. The efficacy of these drugs is affected by glycosylation patterns. Therefore, an in-depth characterization method for the N-glycans is necessary. Here, we present a comprehensive approach for qualitative and quantitative analysis of N-glycans using hydrophilic interaction liquid chromatography equipped with fluorescence detection and tandem mass spectrometry (HILIC-FLD-MS/MS). N-glycans were released from glycoproteins with a facile method and labeled by a procainamide fluorophore tag in the strategy. Subsequently, the procainamide labeled N-glycans were analyzed by a HILIC-FLD-MS/MS technique. In this approach, N-glycan structures were confirmed by the tandem mass spectrometric analysis, whereas fluorescence detection was used for the quantitative analysis. An application for data analysis of the detected N-glycan peaks is described in the study. This protocol can be applied to any glycoprotein extracted from various species.

N-glycan Profiling of Glycoproteins by Hydrophilic Interaction Liquid Chromatography with Fluorescence and Mass Spectrometric Detection

N-glycan profiling of glycoproteins is essential for discovering novel biomarkers and understanding glycan functions in cellular events. Additionally, N-glycan analysis of protein biopharmaceuticals is very important for human use. In this current article, a high-throughput strategy for identifying and quantifying N-glycan structures was presented using the HILIC-FLD-MS/MS technique.

Glycosylation is a vital modification found in proteins. N-glycan profiling of glycoproteins is required to detect novel biomarker candidates and ...

Pulse-chase Analysis of N-linked Sugar Chains from Glycoproteins in Mammalian Cells

Attachment of the Glc3Man9GlcNAc2 precursor oligosaccharide to nascent polypeptides in the ER is a common modification for secretory proteins. Although this modification was implicated in several biological processes, additional aspects of its function are emerging, with recent evidence of its role in the production of signals for glycoprotein quality control and trafficking. Thus, phenomena related to N-linked glycans and their processing are being intensively investigated. Methods that have been recently developed for proteomic analysis have greatly improved the characterization of glycoprotein N-linked glycans. Nevertheless, they do not provide insight into the dynamics of the sugar chain processing involved. For this, labeling and pulse-chase analysis protocols are used that are usually complex and give very low yields. We describe here a simple method for the isolation and analysis of metabolically labeled N-linked oligosaccharides. The protocol is based on labeling of cells with [2-3H] mannose, denaturing lysis and enzymatic release of the oligosaccharides from either a specifically immunoprecipitated protein of interest or from the general glycoprotein pool by sequential treatments with endo H and N-glycosidase F, followed by molecular filtration (Amicon). In this method the isolated oligosaccharides serve as an input for HPLC analysis, which allows discrimination between various glycan structures according to the number of monosaccharide units comprising them, with a resolution of a single monosaccharide. Using this method we were able to study high mannose N-linked oligosaccharide profiles of total cell glycoproteins after pulse-chase in normal conditions and under proteasome inhibition. These profiles were compared to those obtained from an immunoprecipitated ER-associated degradation (ERAD) substrate. Our results suggest that most NIH 3T3 cellular glycoproteins are relatively stable and that most of their oligosaccharides are trimmed to Man9-8GlcNAc2. In contrast, unstable ERAD substrates are trimmed to Man6-5GlcNAc2 and glycoproteins bearing these species accumulate upon inhibition of proteasomal degradation.

We describe a method for analysis of the alteration of N-linked glycans through the early life of glycoproteins after their biosynthesis in mammalian cells. This is achieved by pulse-chase analysis of metabolically labeled glycans, enzymatic release from glycoproteins and examination by HPLC.

N -连接糖链的糖蛋白在哺乳动物细胞中的脉冲大通分析

Attachment of the Glc3Man9GlcNAc2 precursor oligosaccharide to nascent polypeptides in the ER is a common modification for secretory proteins. Although ...

生物学

A Spin-Tip Enrichment Strategy for Simultaneous Analysis of N-Glycopeptides and Phosphopeptides from Human Pancreatic Tissues

Mass spectrometry can provide deep coverage of post-translational modifications (PTMs), although enrichment of these modifications from complex biological matrices is often necessary due to their low stoichiometry in comparison to non-modified analytes. Most enrichment workflows of PTMs on peptides in bottom-up proteomics workflows, where proteins are enzymatically digested before the resulting peptides are analyzed, only enrich one type of modification. It is the entire complement of PTMs, however, that leads to biological functions, and enrichment of a single type of PTM may miss such crosstalk of PTMs. PTM crosstalk has been observed between protein glycosylation and phosphorylation, the two most common PTMs in human proteins and also the two most studied PTMs using mass spectrometry workflows. Using the simultaneous enrichment strategy described herein, both PTMs are enriched from post-mortem human pancreatic tissue, a complex biological matrix. Dual-functional Ti(IV)-immobilized metal affinity chromatography is used to separate various forms of glycosylation and phosphorylation simultaneously in multiple fractions in a convenient spin tip-based method, allowing downstream analyses of potential PTM crosstalk interactions. This enrichment workflow for glyco- and phosphopeptides can be applied to various sample types to achieve deep profiling of multiple PTMs and identify potential target molecules for future studies.

Post-translational modifications (PTMs) change protein structures and functions. Methods for the simultaneous enrichment of multiple PTM types can maximize coverage in analyses. We present a protocol using dual-functional Ti(IV)-immobilized metal affinity chromatography followed by mass spectrometry for the simultaneous enrichment and analysis of protein N-glycosylation and phosphorylation in pancreatic tissues.

一种同时分析人胰腺组织中N-糖肽和磷酸肽的自旋尖端富集策略

Mass spectrometry can provide deep coverage of post-translational modifications (PTMs), although enrichment of these modifications from complex biological ...

<meta charset="utf8"></head><body>使用糖组学指导的糖蛋白质组学分析结直肠癌组织

Glycomics-Guided Glycoproteomics Facilitates Comprehensive Profiling of the Glycoproteome in Complex Tumor Microenvironments

Glycosylation is a common and structurally diverse protein modification that impacts a wide range of tumorigenic processes. Mass spectrometry-driven glycomics and glycoproteomics have emerged as powerful approaches to analyze liberated glycans and intact glycopeptides, respectively, offering a deeper understanding of the heterogeneous glycoproteome in the tumor microenvironment (TME). This protocol details the glycomics-guided glycoproteomics method, an integrated omics technology, which firstly employs porous graphitized carbon-LC-MS/MS-based glycomics to elucidate the glycan structures and their quantitative distribution in the glycome of tumor tissues, cell populations, or bodily fluids being investigated. This allows for a comparative glycomics analysis to identify altered glycosylation across patient groups, disease stages, or conditions, and, importantly, serves to enhance the downstream glycoproteomics analysis of the same sample(s) by creating a library of known glycan structures, thus reducing the data search time and the glycoprotein misidentification rate. Focusing on N-glycoproteome profiling, the sample preparation steps for the glycomics-guided glycoproteomics method are detailed in this protocol, and key aspects of the data collection and analysis are discussed. The glycomics-guided glycoproteomics method provides quantitative information on the glycoproteins present in the TME and their glycosylation sites, site occupancy, and site-specific glycan structures. Representative results are presented from formalin-fixed paraffin-embedded tumor tissues from colorectal cancer patients, demonstrating that the method is sensitive and compatible with tissue sections commonly found in biobanks. Glycomics-guided glycoproteomics, therefore, offers a comprehensive view into the heterogeneity and dynamics of the glycoproteome in complex TMEs, generating robust biochemical data required to better understand the glycobiology of cancers.

<meta charset="utf8"></head><body>糖组学引导的糖蛋白质组学有助于在复杂的肿瘤微环境中全面分析糖蛋白质组

This protocol details the glycomics-guided glycoproteomics method, an integrated omics technology that offers comprehensive insights into the heterogeneous glycoproteome in complex tumor microenvironments required to better understand the glycobiology of cancers.

糖组学引导的糖蛋白质组学有助于在复杂的肿瘤微环境中全面分析糖蛋白质组 

Glycosylation is a common and structurally diverse protein modification that impacts a wide range of tumorigenic processes. Mass spectrometry-driven ...

癌症研究

Identifying Cell Surface Markers of Primary Neural Stem and Progenitor Cells by Metabolic Labeling of Sialoglycan

Neural stem and progenitor cells (NSPCs) are the cellular basis for the complex structures and functions of the brain. They are located in specialized niches in vivo and can be isolated and expanded in vitro, serving as an important resource for cell transplantation to repair brain damage. However, NSPCs are heterogeneous and not clearly defined at the molecular level or purified due to a lack of specific cell surface markers. The protocol presented, which has been previously reported, combines a neural-endothelial co-culture system with a metabolic glycan labeling method to identify the surface sialoglycoproteome of primary NSPCs. The NSPC-endothelial co-culture system allows self-renewal and expansion of primary NSPCs in vitro, generating a sufficient number of NSPCs. Sialoglycans in cultured NSPCs are labeled using an unnatural sialic acid metabolic reporter with bioorthogonal functional groups. By comparing the sialoglycoproteome from self-renewing NSPCs expanded in an endothelial co-culture with differentiating neural culture, we identify a list of membrane proteins that are enriched in NSPCs. In detail, the protocol involves: 1) set-up of an NSPC-endothelial co-culture and NSPC differentiating culture; 2) labeling with azidosugar per-O-acetylated N-azidoacetylmannosamine (Ac4ManNAz); and 3) biotin conjugation to modified sialoglycan for imaging after fixation of neural culture or protein extraction from neural culture for mass spectrometry analysis. Then, the NSPC-enriched surface marker candidates are selected by comparative analysis of mass spectrometry data from both the expanded NSPC and differentiated neural cultures. This protocol is highly sensitive for identifying membrane proteins of low abundance in the starting materials, and it can be applied to marker discovery in other systems with appropriate modifications

Presented here is a protocol that combines an in vitro neural-endothelial co-culture system and metabolic incorporation of sialoglycan with bioorthogonal functional groups to expand primary neural stem and progenitor cells and label their surface sialoglycoproteins for imaging or mass-spectrometry analysis of cell surface markers.

通过Sialoglycan的代谢标记识别主要神经干细胞和祖细胞的细胞表面标记

Neural stem and progenitor cells (NSPCs) are the cellular basis for the complex structures and functions of the brain. They are located in specialized ...

SCAP分析

摘要

探索更多视频

此视频中的章节

聚糖节点分析:自下而上的方法，以糖原组学

用 X 射线晶体学和生物物理技术表征免疫球蛋白折叠的糖蛋白

培养细胞功能化纳米化对跨 golgi 网络的内分泌吸收和逆行迁移分析

N-glycan Profiling of Glycoproteins by Hydrophilic Interaction Liquid Chromatography with Fluorescence and Mass Spectrometric Detection

N -连接糖链的糖蛋白在哺乳动物细胞中的脉冲大通分析

一种同时分析人胰腺组织中N-糖肽和磷酸肽的自旋尖端富集策略

糖组学引导的糖蛋白质组学有助于在复杂的肿瘤微环境中全面分析糖蛋白质组

糖组学引导的糖蛋白质组学有助于在复杂的肿瘤微环境中全面分析糖蛋白质组

糖组学引导的糖蛋白质组学有助于在复杂的肿瘤微环境中全面分析糖蛋白质组

通过Sialoglycan的代谢标记识别主要神经干细胞和祖细胞的细胞表面标记