우리는 질량 분석 분석 및 유용한 의견에 대 한 박사 데이비드 킹, 하 워드 휴즈 의학 연구소, 캘리포니아 대학 버클리를 감사합니다. 우리는 박사 Xuelian 주, 상하이, 생물 과학을 위한 학회, 과학의 중국 아카데미, 상하이, 중국 전체 길이 CENP F 구조를 제공 하기 위한 감사 합니다. 마지막으로, 우리는 감사 박사 수잔 베인 박사 브라이언 칼라, 빙 엄 턴 대학에서 박사 Christof Grewer 장비에 대 한 액세스. 이 연구는 뉴욕의 주립 대학 및 대학의 뉴욕 주립 빙햄 턴 화학과 연구 재단에 의해 투자 되었다.

저자는 공개 없다.

우리의 생체 외에서 니 분석 결과 세포 주기의 마스터 컨트롤러 및 많은 중요 한 세포질 과정을 조절 키 Cdk1를 위한 분자 표적을 식별 하는 매우 강력한 방법입니다. 메서드는 순화 된 단백질 Cdk1에 대 한 기판 이며 수 인 산화 특정 사이트의 경우 결정 합니다. 이 Cdk1 통해 인 산화에 의해 세포 프로세스의 규칙을 위한 기계 연구를 촉진 한다.
질량 분석에 의해 인 산화 위...

Kinases는 기판에 ATP에서 인산 염 그룹을 전송 하 고 많은 세포질 과정을 조절 하는 효소. 이 인 산화 되돌릴 수, 빠르고, 두 부정적인 요금을 추가 및 저장 자유 에너지, 하 고 셀에서 사용 하는 가장 일반적인 posttranslational 수정 중 하나입니다. Cdk1, 일컬어 세포 주기 단백질 2 체 (cdc2)는 모든 진핵생물1,2,3,,45, 세포 주기 위해 마스터 컨트롤러가 고 phosphorylates는 프로테옴6,7의 예상된 8-13%.
최근 proteomic 연구는 단백질, 대부분의 경우에서에 많은 인 산화 사이트를 확인 하는 동안 키 이러한 수정에 대 한 책임을 알 수 있다. 인간 세포에서 특히 알려진된 Cdk1 목표의 수는 낮은7. Cdk1-특정 한 인 산화 위치의 식별 Cdk1 세포 주기를 제어 하는 방법을 설정 하는 기계 론 적인 연구를 하면 그것은 중요 하다. 세포 주기 규칙은 충실 한 염색체 분리 및 세포 분열에 대 한 중요 한 그리고 세포질 과정의 무수 한이 중요 한 생리 기능을 지원 하기 위해 발생 해야 합니다. 전사와 유사 분열, 세포의 구조와 핵, 염색체 응축, mitotic 스핀 들 어셈블리의 분해 등의 조직에 극적인 개편의 발병 이전 번역 중단 포함 됩니다. 규제 완화와 이러한 프로세스에서 오류가 발생할 암, 출생 결함, 또는 mitotic 세포 죽음. RO-3306 같은 Cdk1의 특정 억제제 개발된8, 기능성 연구를 위한 강력한 도구를 제공 하는 되었고 이러한 억제제 중 일부는 현재 암 치료에 대 한 임상 시험 (검토를 위해9 참조).
여기, 우리가 시험관에서 키 분석 결과 Cdk1 관련 인 산화 위치의 식별 수 있도록 설명 합니다. 이 분석 결과에서 상용 인간 Cdk1/ B는 순화 대상 단백질에서 생체 외에서phosphorylate 데 사용 됩니다. 기판의 인 산화의 질량을 증가 하 고 추가 두 음 전; 따라서, 성공적인 인 산화는 SDS 페이지에 단백질 젤 밴드의 상승 교대에 의해 확인 된다. 인 산화 Cdk1 특정 사이트 이후 체 외에 phosphorylated 단백질의 질량 분석 분석에 의해 식별 됩니다. 실험적인 디자인으로 돕기 위해 우리는 또한 계산 도구와 단백질 시퀀스에서 Cdk1 관련 인 산화 위치의 예측에 대 한 참조를 검토 합니다. 또한, 우리는 또한 매우 순수 하 고 균질 단백질 준비 니 분석 결과 대 한 적합 한 생성 하는 정화 프로토콜 설명 합니다. 마지막으로, 기능 연구에 의해 확인 된 인 산화 사이트를 확인 해야 합니다 그리고 여기에 설명 된 간단한 바인딩 분석 결과 그 목적을 위해. 결합, 이것은 매우 강력한 접근 Cdk1 세포 주기7,,1011를 제어 하는 방법으로 기계 론 적인 연구를 가능 하 게 Cdk1 관련 인 산화 사이트를 생성. 이 메서드는 순화 된 단백질에 의존, 이후 모든 모델 유기 체 및 수율 신뢰할 수 있는 결과에 적용할 수 있습니다. 그러나, 취득된 인 산화 사이트에는 생체 외에서 의 기능 확인은 권장, 셀 추가 규제 메커니즘 posttranslational 수정, 상호 파트너 또는 셀룰러 지역화 같은 장소에는 인 산화 사이트 액세스할 수 또는 Cdk1에 의해 인식에 대 한 액세스할 수 없게 렌더링 수 있습니다.
Cdk1 어디 X 어떤 잔류물 이며 떠들고 또는 트레오닌 인 산화의 사이트 (Ser/Thr-프로-X-리스/Arg), 구성 된 합의 인 산화 사이트를 인식 합니다. 특히 중요 한 인식에 대 한 + 1 위치에 프롤린의 존재가입니다. + 2 또는 3 위치에 기본적인 잔류물을 선호 하는 또한, 대부분 Cdk1 관련 인 산화 사이트는 + 3에서 리스 또는 Arg를 포함 위치6,12.
Cdk1의 활성화 긴밀 하 게 규제 하 고 유사 분열1,2,3,,45의 발병에 연결 됩니다.  종속 kinases의 활동 일반적으로 진동 세포 주기13전역 수준에서 표현 되는 뚜렷한 cyclins ( A, B, C, D, 그리고 E 인간에서), 그들의 연관에 따라 달라 집니다. Cdk1는 일정 한 세포 주기 고  A와 B5,13,,1415로  규제 소 단위와의 연결에 의존 하는 그것의 활동의 규제 뿐만 아니라 포스트 번역 상 수정. Cdk1/ B 복합체의 형성이 키 니 아 제 활성화5,14,15,,1617,18에 대 한 필요 합니다. G2 단계  B는 cytosol에서 번역 및 그것은 Cdk15,14,15,16,,1718; 바인딩 핵을 가져올 그러나, Cdk1/ B 인간 Cdk1 억제 kinases Myt1에 의해 Thr14와 Tyr15 잔류물에 인 산화 (멤브레인 관련 티로신, 트레오닌-특정 cdc2 억제 키)와 Wee1, 각각19, 사 개최 20,21. 늦은 G2 단계에서 세포 분열 주기 25 인산 가수분해 효소 (cdc25)에 의해 Thr14와 Tyr15의 dephosphorylation Cdk1/ B 복합의 키 니 아 제 활동을 활성화 하 고 유사 분열12,14, 의 개시를 유발 18 , 20 , 22 , 23. Thr161 인 산화는 Cdk1/ B 활성화에도 필요 하 고 Cdk7, Cdk 활성화 키 (케이크)18에 의해 중재입니다.  B anaphase에의 생긴다 Cdk1을, 유사 분열24,25에서 출구를 허용. Cdk1/ B의 활성화는 따라서 복잡 한 과정입니다. 여기에 제시 된 프로토콜 상용 Cdk1/ b 수행 곤충 세포에서이 복합물의 재조합 식 동안 활성화 된 vivo에서 생 kinases14,20 이며 순화 된 상태에서 활성 상태로 유지 합니다. 결과 활성화, 재조합 인간 Cdk1/ B는 생체 외에서 키 니 아 제 분석 실험에 적합 합니다.
여기, 우리는 인간의 centromere 단백질 F (CENP F)10Cdk1 관련 인 산화 위치의 식별에 대 한 프로토콜을 설명합니다. CENP-F는 대부분 interphase (g 1과 S 상)의 중 핵에 있는 g 2 단계26,27,28 , Cdk1 종속 방식으로10에 cytosol에 수출 하는 kinetochore 단백질 11. 핵 지역화26이 분 cNLS 의해 수 여. cNLSs 핵 전송 요소 karyopherin α karyopherin β 및 RanGDP, 핵29에 cNLS 화물의 수입 촉진에 의해 인식 됩니다. G2 단계에서 핵 수출10알 수 없는 수출 통로 통해 촉진 된다. CENP-F는 cytosol에 있는, 일단 핵을 모집 하 고 차례 차례로 모터 단백질 복잡 한 다30,31신병. 이 통로 mitotic 항목의 정확한 타이밍에 대 한 및 두뇌에 있는 근본적인 과정에 대 한 중요 한 다 종속 방식 mitotic 스핀 들 어셈블리의 초기 단계는 centrosome 각각 핵 위치 하는 것이 중요 하다 개발30,,3132. G 2 단계에서 시작 해 서, CENP-F 또한 조립 되는 kinetochore에 충실 한 염색체 분리27,28,,3334,35에 대 한 중요 한 역할을가지고 . 이 통로의 주요 규제 단계는 Cdk110,11에 따라 g 2 단계에서 CENP-F의 핵 수출 이다. 여기 CENP F. cNLS에 Cdk1-관련 인 산화 위치의 식별 프로토콜 설명 이 사이트의 Phosphomimetic 돌연변이 CENP-f, B Cdk1/ 직접 CENP-F의 그것의 cNLS10의 인 산화에 의해 세포 지역화 조절 제안 핵 가져오기 천천히.
전반적으로,이 생체 외에서 니 분석 결과 수 있습니다 특정 기판의 식별을 키 Cdk1 정화 대상 단백질 phosphorylated 생체 외에서 상용 Cdk1/ B 복합물 및 인 산화 사이트에 대 한 이후 질량 분석에 의해 식별 됩니다. Cdk1-특정 한 인 산화 위치의 식별 Cdk1 세포 주기를 제어 하는 방법을 계시 하는 기계 론 적인 연구를 지원 합니다.

<table><tbody><tr><td>2800 mL baffled Fernbach flask</td><td>Corning</td><td>44232XL</td><td></td></tr><tr><td>ampicillin</td><td>Gold Biotechnology</td><td>A-301-25</td><td></td></tr><tr><td>ATP</td><td>Fisher Scientfiic</td><td>BP413-25</td><td></td></tr><tr><td>benzamidine hydrochloride</td><td>Millipore Sigma</td><td>B6506-25</td><td></td></tr><tr><td>bottletop filter</td><td>Corning</td><td>431161</td><td></td></tr><tr><td>Cdk1/cyclin B recombinant, human 20,000 U/mL</td><td>New England Biolabs</td><td>P6020</td><td></td></tr><tr><td>Cdk1/cyclin B (alternate source)</td><td>EMD Millipore</td><td>14-450</td><td></td></tr><tr><td>Cdk1/cyclin B (alternate source)</td><td>Invitrogen</td><td>PV3292</td><td></td></tr><tr><td>Cdk1/cyclin B + 10x PK buffer</td><td>New England Biolabs</td><td>P6020</td><td></td></tr><tr><td>CENP-F (residues 2987 &amp;ndash; 3065) pGEX6P1 plasmid</td><td>Available upon request.</td><td></td><td></td></tr><tr><td>centrifuge: Heraeus Multifuge X3R, cooled, with TX-1000 swing-out rotor</td><td>Thermo Scientific</td><td>10033-778</td><td></td></tr><tr><td>centrifugal filter units: Amicon Ultra-15 centrifugal filter units, 3 kDa cutoff, Ultracel-PL membranes</td><td>EMD Millipore</td><td>UFC900324</td><td></td></tr><tr><td>chlorampenicol</td><td>Gold Biotechnology</td><td>C-105-100</td><td></td></tr><tr><td>D/L methionine</td><td>Agros Organics / Fisher</td><td>125650010</td><td></td></tr><tr><td>desalting pipet tips: Zip tips</td><td>Millipore Sigma</td><td>ZTC18S008</td><td></td></tr><tr><td>disposable chromatography columns, Econo-Pac 1.5 x 12 cm</td><td>Biorad</td><td>7321010</td><td></td></tr><tr><td>dithiothreitol</td><td>Gold Biotechnology</td><td>DTT50</td><td></td></tr><tr><td>&lt;em&gt;E. coli&lt;/em&gt; Rosetta 2(DE3)pLysS strain</td><td>EMD Millipore</td><td>71403</td><td></td></tr><tr><td>electrospray ionization Fourier transform ion</td><td>Bruker Amazon</td><td>Apex III</td><td></td></tr><tr><td>cyclotron resonance mass spectrometer</td><td></td><td></td><td></td></tr><tr><td>electrospray ionization ion trap mass spectrometer</td><td>Bruker Amazon</td><td>custom</td><td></td></tr><tr><td>fixed angle rotor: Fiberlite F15-8x-50cy</td><td>Thermo Scientific</td><td>97040-276</td><td></td></tr><tr><td>FPLC system: &amp;Auml;kta Pure FPLC</td><td>GE Healthcare</td><td>29032697</td><td></td></tr><tr><td>Gel filtration column: Superdex 200 Increase 10/300 GL</td><td>GE Healthcare</td><td>28990944</td><td></td></tr><tr><td>glutathione agarose</td><td>Pierce</td><td>16101</td><td></td></tr><tr><td>glutathione, reduced</td><td>Millipore Sigma</td><td>G4251-50g</td><td></td></tr><tr><td>incubation shaker: multitron shaker</td><td>Infors</td><td>I10102</td><td></td></tr><tr><td>isopropyl &amp;beta;-D-1-thiogalactopyranoside</td><td>Gold Biotechnology</td><td>I2481C50</td><td></td></tr><tr><td>kanamycin</td><td>Gold Biotechnology</td><td>K-120-25</td><td></td></tr><tr><td>karyopherin &amp;alpha; pet-28a pres plasmid</td><td>Available upon request.</td><td></td><td></td></tr><tr><td>Luria Bertani medium</td><td>Fisher Scientfiic</td><td>BP1426-2</td><td></td></tr><tr><td>microcentrifuge 5418R, refrigerated</td><td>Eppendorf</td><td>5401000013</td><td></td></tr><tr><td>microtubes (0.5 mL)</td><td>Eppendorf</td><td>30121023</td><td></td></tr><tr><td>microtubes (1.5 mL)</td><td>Eppendorf</td><td>30120086</td><td></td></tr><tr><td>Nickel affinity gel: His-Select Nickel affinity gel</td><td>Millipore Sigma</td><td>P6611-100ml</td><td></td></tr><tr><td>pGEX-6P-1 plasmid</td><td>Millipore Sigma</td><td>GE28-9546-48</td><td></td></tr><tr><td>phenylmethylsulfonyl fluoride</td><td>Gold Biotechnology</td><td>P470-10</td><td></td></tr><tr><td>PS protease: PreScission protease</td><td>GE Healthcare</td><td>27084301</td><td></td></tr><tr><td>Phos-tag acrylamide</td><td>Wako Pure Chem. Ind.</td><td>304-93521</td><td></td></tr><tr><td>reduced gluthathione</td><td>Millipore Sigma</td><td>G4251-50g</td><td></td></tr><tr><td>roundbottom centrifuge tubes (Oakridge tubes)</td><td>Fisher Scientfiic</td><td>055291D</td><td></td></tr><tr><td>site-directed mutagenesis kit: QuikChange Lightning</td><td>Agilent</td><td>210518</td><td></td></tr><tr><td>Site-Directed Mutagenesis Kit</td><td></td><td></td><td></td></tr><tr><td>sonifier: Branson S-250D sonifier</td><td>Branson</td><td>15 338 125</td><td></td></tr><tr><td>Spectra/Por 1RC dialysis membrane (6-8 kDa cutoff)</td><td>Spectrum Labs</td><td>08 670B</td><td></td></tr><tr><td>swing out rotor TX-1000</td><td>Thermo Scientific</td><td>10033-778</td><td></td></tr></tbody></table>

identification of cyclin-dependent kinase 1 specific phosphorylation sites by an in vitro kinase assay

 종속 키 1 (Cdk1)는 모든 진핵생물의 세포 주기 위한 마스터 컨트롤러와 프로테옴;의 약된 8-13% phosphorylates 그러나, Cdk1, 특히 인간의 세포에에서 대 한 확인된 대상 수 여전히 낮습니다. Cdk1-특정 한 인 산화 위치의 식별 중요 하다, 그들은 Cdk1 세포 주기를 제어 하는 방법에 대 한 기계적 통찰력을 제공. 세포 주기 규칙 충실 한 염색체 분리에 대 한 중요 하 고이 복잡 한 과정에 결함 염색체 착오 및 암으로 이어질.
여기, 우리가 시험관에서 키 분석 결과 Cdk1 관련 인 산화 위치를 식별 하는 데 사용 되는 설명 합니다. 이 분석 결과, 순화 된 단백질은 phosphorylated 생체 외에서 상용 인간 Cdk1/ B. 성공에 의해 인 산화 SDS 페이지에서 확인 및 인 산화 사이트 이후 질량 분석에 의해 식별 됩니다. 우리는 또한 정화 프로토콜 간의 상호 작용을 조사 확인 된 인 산화 위치의 기능 검증에 대 한 키 니 아 제 분석 실험 및 바인딩 분석 결과 대 한 적합 한 매우 순수 하 고 균질 단백질 준비 항복을 설명합니다 클래식 핵 지 방화 신호 (cNLS) 그리고 그것의 핵 수송 수용 체 karyopherin α. 실험 설계와 투입, 단백질 시퀀스에서 Cdk1 관련 인 산화 위치의 예측에 대 한 접근 방법을 검토 합니다. 함께 이러한 프로토콜 Cdk1 전용 인 산화 사이트를 생성 하 고 Cdk1 세포 주기를 제어 하는 방법으로 기계 론 적인 연구는 매우 강력한 접근 방식을 제공 합니다. 때문에이 메서드는 순화 된 단백질에 의존, 그것은 적용할 수 있습니다 어떤 모델 유기 체 및 수율 신뢰할 수 있는 결과에, 세포 기능 연구와 결합 하는 경우에 특히.

최근 포함 cNLS10CENP-F 조각에서 Cdk1 관련 인 산화 사이트를 식별 하는 생체 외에서 니 분석 결과 (그림 1) 사용 했습니다. 이 신호는 대부분의 interphase 동안 CENP F의 핵 지역화를 수 여. G2 단계에서 CENP F Cdk1 종속 방식에서 cytosol에 핵에서 수출 된다. Cdk1 CENP-F의 셀룰러 지역화를 조절 하는 방법에 대 한 기계적 통찰력을 얻으려면, ?...

Watch this Scientific Journal Video about Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay at JoVE.com

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay

 종속 키 1 (Cdk1) 세포 주기의 g 2 단계에서 활성화 되 고 많은 세포 경로 조절. 여기, Cdk1, Cdk1-특정 한 인 산화 위치의 식별이 중요 한 키의 셀룰러 목표 설정에 대 한 수와 함께 체 외에 니 분석 결과 대 한 프로토콜 선물이.

 종속 키 1의 시험관에서 키에 의해 인 산화 특정 사이트 분석 결과

Cyclin-dependent kinase 1 (Cdk1) is a master controller for the cell cycle in all eukaryotes and phosphorylates an estimated 8 - 13% of the proteome; ...

identification-cyclin-dependent-kinase-1-specific-phosphorylation

Universidad de Cartagena UDEC

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Biochemistry

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay

18.5K 조회수.  State University of New York at Binghamton.  종속 키 1 (Cdk1) 세포 주기의 g 2 단계에서 활성화 되 고 많은 세포 경로 조절. 여기, Cdk1, Cdk1-특정 한 인 산화 위치의 식별이 중요 한 키의 셀룰러 목표 설정에 대 한 수와 함께 체 외에 니 분석 결과 대 한 프로토콜 선물이.

비디오: Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay

Assaying Protein Kinase Activity with Radiolabeled ATP

Protein kinases are able to govern large-scale cellular changes in response to complex arrays of stimuli, and much effort has been directed at uncovering allosteric details of their regulation. Kinases comprise signaling networks whose defects are often hallmarks of multiple forms of cancer and related diseases, making an assay platform amenable to manipulation of upstream regulatory factors and validation of reaction requirements critical in the search for improved therapeutics. Here, we describe a basic kinase assay that can be easily adapted to suit specific experimental questions including but not limited to testing the effects of biochemical and pharmacological agents, genetic manipulations such as mutation and deletion, as well as cell culture conditions and treatments to probe cell signaling mechanisms. This assay utilizes radiolabeled [&#947;-32P] ATP, which allows for quantitative comparisons and clear visualization of results, and can be modified for use with immunoprecipitated or recombinant kinase, specific or typified substrates, all over a wide range of reaction conditions.

Protein kinases are highly evolved signaling enzymes and scaffolds that are critical for inter- and intracellular signal transduction. We present a protocol for measuring kinase activity through the use of radiolabeled adenosine triphosphate ([&#947;-32P] ATP), a reliable method to aid in elucidation of cellular signaling regulation.

방사성 표지 된 ATP로 단백질 키나아제 활성 측정

Protein kinases are able to govern large-scale cellular changes in response to complex arrays of stimuli, and much effort has been directed at uncovering ...

연구

생화학

Oligopeptide Competition Assay for Phosphorylation Site Determination

Protein phosphorylation at specific sites determines its conformation and interaction with other molecules. Thus, protein phosphorylation affects biological functions and characteristics of the cell. Currently, the most common method for discovering phosphorylation sites is by liquid chromatography/mass spectrometry (LC/MS) analysis, a rapid and sensitive method. However, relatively labile phosphate moieties are often released from phosphopeptides during the fragmentation step, which often yields false-negative signals. In such cases, a traditional in vitro kinase assay using site-directed mutants would be more accurate, but this method is laborious and time-consuming. Therefore, an alternative method using peptide competition may be advantageous. The consensus recognition motif of 5&#39; adenosine monophosphate-activated protein kinase (AMPK) has been established1 and was validated using a positional scanning peptide library assay2. Thus, AMPK phosphorylation sites for a novel substrate could be predicted and confirmed by the peptide competition assays. In this report, we describe the detailed steps and procedures for the in vitro oligopeptide-competing kinase assay by illustrating AMPK-mediated nuclear factor erythroid 2-related factor 2 (Nrf2) phosphorylation. To authenticate the phosphorylation site, we carried out a sequential in vitro kinase assay using a site-specific mutant. Overall, the peptide competition assay provides a method to screen multiple potential phosphorylation sites and to identify sites for validation by the phosphorylation site mutants.

Peptide competition assays are widely used in a variety of molecular and immunological experiments. This paper describes a detailed method for an in vitro oligopeptide-competing kinase assay and the associated validation procedures, which may be useful to find specific phosphorylation sites.

인산화 부위 결정을위한 올리고 펩타이드 경쟁 분석

Protein phosphorylation at specific sites determines its conformation and interaction with other molecules. Thus, protein phosphorylation affects ...

Identification of Novel CK2 Kinase Substrates Using a Versatile Biochemical Approach

The study of kinase-substrate relationships is essential to gain a complete understanding of the functions of these enzymes and their downstream targets in both physiological and pathological states. CK2 is an evolutionarily conserved serine/threonine kinase with a growing list of hundreds of substrates involved in multiple cellular processes. Due to its pleiotropic properties, identifying and characterizing a comprehensive set of CK2 substrates has been particularly challenging and remains a hurdle in the study of this important enzyme. To address this challenge, we have devised a versatile experimental strategy that enables the targeted enrichment and identification of putative CK2 substrates. This protocol takes advantage of the unique dual co-substrate specificity of CK2 allowing for specific thiophosphorylation of its substrates in a cell or tissue lysate. These substrate proteins are subsequently alkylated, immunoprecipitated, and identified by liquid chromatography/tandem mass spectrometry (LC-MS/MS). We have previously used this approach to successfully identify CK2 substrates from Drosophila ovaries and here we extend the application of this protocol to human glioblastoma cells, illustrating the adaptability of this method to investigate the biological roles of this kinase in various model organisms and experimental systems.

The objective of this protocol is to label, enrich, and identify substrates of protein kinase CK2 from a complex biological sample such as a cell lysate or tissue homogenate. This method leverages unique aspects of CK2 biology for this purpose.

다양 한 생 화 확 적인 접근을 사용 하 여 소설 CK2 키 기판의 식별

The study of kinase-substrate relationships is essential to gain a complete understanding of the functions of these enzymes and their downstream targets ...

Characterization at the Molecular Level using Robust Biochemical Approaches of a New Kinase Protein

Extensive whole genome sequencing has identified many Open Reading Frames (ORFs) providing many potential proteins. These proteins may have important roles for the cell and may unravel new cellular processes. Among proteins, kinases are major actors as they belong to cell signaling pathways and have the ability to switch on or off many processes crucial to the fate of the cell, such as cell growth, division, differentiation, motility, and death.
In this study, we focused on a new potential kinase protein, LIMK2-1. We demonstrated its existence by Western Blot using a specific antibody. We evaluated its interaction with an upstream regulating protein using coimmunoprecipitation experiments. Coimmunoprecipitation is a very powerful technique able to detect the interaction between two target proteins. It may also be used to detect new partners of a bait protein. The bait protein may be purified either via a tag engineered to its sequence or via an antibody specifically targeting it. These protein complexes may then be separated by SDS-PAGE (Sodium Dodecyl Sulfate PolyAcrylamide Gel) and identified using mass spectrometry. Immunoprecipitated LIMK2-1 was also used to test its kinase activity in vitro by &#947;[32P] ATP labeling. This well-established assay may use many different substrates, and mutated versions of the bait may be used to assess the role of specific residues. The effects of pharmacological agents may also be evaluated since this technique is both highly sensitive and quantitative. Nonetheless, radioactivity handling requires particular caution. Kinase activity may also be assessed with specific antibodies targeting the phospho group of the modified amino acid. These kinds of antibodies are not commercially available for all the phospho modified residues.

We characterized a new kinase protein using robust biochemical approaches: Western Blot analysis with a dedicated specific antibody on different cell lines and tissues, interactions by coimmunoprecipitation experiments, kinase activity detected by Western Blot using a phospho-specific antibody and by &#947;[32P] ATP labeling.

새로운 키나제 단백질의 강력한 생화학 적 접근법을 사용하여 분자 수준에서특성화

Extensive whole genome sequencing has identified many Open Reading Frames (ORFs) providing many potential proteins. These proteins may have important ...

Non-Radioactive In Vitro Cardiac Myosin Light Chain Kinase Assays

Cardiac-specific myosin regulatory light chain kinase (cMLCK) regulates cardiac sarcomere structure and contractility by phosphorylating the ventricular isoform of the myosin regulatory light chain (MLC2v). MLC2v phosphorylation levels are significantly reduced in failing hearts, indicating the clinical importance of assessing the activity of cMLCK and the phosphorylation level of MLC2v to elucidate the pathogenesis of heart failure. This paper describes nonradioactive methods to assess both the activity of cMLCK and MLC2v phosphorylation levels. In vitro kinase reactions are performed using recombinant cMLCK with recombinant calmodulin and MLC2v in the presence of ATP and calcium at 25 &#176;C, which are followed by either a bioluminescent ADP detection assay or a phosphate-affinity SDS-PAGE. In the representative study, the bioluminescent ADP detection assay showed a strict linear increase of the signal at cMLCK concentrations between 1.25 nM to 25 nM. Phosphate-affinity SDS-PAGE also showed a linear increase of phosphorylated MLC2v in the same cMLCK concentration range. Next, the time-dependency of the reactions was examined at the concentration of 5 nM cMLCK. A bioluminescent ADP detection assay showed a linear increase in the signal during 90 min of the reaction. Similarly, phosphate-affinity SDS-PAGE showed a time-dependent increase of phosphorylated MLC2v. The biochemical parameters of cMLCK for MLC2v were determined by a Michaelis-Menten plot using the bioluminescent ADP detection assay. The Vmax was 1.65 &#177; 0.10 mol/min/mol kinase and the average Km was around 0.5 USA &#181;M at 25 &#176;C. Next, the activity of wild type and the dilated cardiomyopathy-associated p.Pro639Valfs*15 mutant cMLCK were measured. The bioluminescent ADP detection assay and phosphate-affinity SDS-PAGE correctly detected defects in cMLCK activity and MLC2v phosphorylation, respectively. In conclusion, a combination of the bioluminescent ADP detection assay and the phosphate-affinity SDS-PAGE is a simple, accurate, safe, low-cost, and flexible method to measure cMLCK activity and the phosphorylation level of MLC2v.

This study describes protocols for nonradiometric methods, a bioluminescent ADP detection assay and a phosphate-affinity SDS-PAGE, to determine the kinase activity of cardiac myosin light chain kinase (cMLCK) and the phosphorylation level of its substrate, myosin regulatory light chain (MLC2v).

Cardiac-specific myosin regulatory light chain kinase (cMLCK) regulates cardiac sarcomere structure and contractility by phosphorylating the ventricular ...

Monitoring Kinase and Phosphatase Activities Through the Cell Cycle by Ratiometric FRET

F&ouml;rster resonance energy transfer (FRET)-based reporters1 allow the assessment of endogenous kinase and phosphatase activities in living cells. Such probes typically consist of variants of CFP and YFP, intervened by a phosphorylatable sequence and a phospho-binding domain. Upon phosphorylation, the probe changes conformation, which results in a change of the distance or orientation between CFP and YFP, leading to a change in FRET efficiency (Fig 1). Several probes have been published during the last decade, monitoring the activity balance of multiple kinases and phosphatases, including reporters of PKA2, PKB3, PKC4, PKD5, ERK6, JNK7, Cdk18, Aurora B9 and Plk19. Given the modular design, additional probes are likely to emerge in the near future10. 
Progression through the cell cycle is affected by stress signaling pathways 11. Notably, the cell cycle is regulated differently during unperturbed growth compared to when cells are recovering from stress12.Time-lapse imaging of cells through the cell cycle therefore requires particular caution. This becomes a problem particularly when employing ratiometric imaging, since two images with a high signal to noise ratio are required to correctly interpret the results. Ratiometric FRET imaging of cell cycle dependent changes in kinase and phosphatase activities has predominately been restricted to sub-sections of the cell cycle8,9,13,14.
Here, we discuss a method to monitor FRET-based probes using ratiometric imaging throughout the human cell cycle. The method relies on equipment that is available to many researchers in life sciences and does not require expert knowledge of microscopy or image processing.

FRET-based reporters are increasingly used to monitor kinase and phosphatase activities in live cells. Here we describe a method on how to use FRET-based reporters to assess cell cycle-dependent changes in target phosphorylation.

안달 Ratiometric하여 세포주기를 통해 키나제와 인산 가수 분해 효소 활동을 모니터링

F&ouml;rster resonance energy transfer (FRET)-based reporters1 allow the assessment of endogenous kinase and phosphatase activities in living cells. Such ...

생물학

Assaying the Kinase Activity of LRRK2 in vitro

Leucine Rich Repeat Kinase 2 (LRRK2) is a 2527 amino acid member of the ROCO family of proteins, possessing a complex, multidomain structure including a GTPase domain (termed ROC, for Ras of Complex proteins) and a kinase domain1. The discovery in 2004 of mutations in LRRK2 that cause Parkinson's disease (PD) resulted in LRRK2 being the focus of a huge volume of research into its normal function and how the protein goes awry in the disease state2,3. Initial investigations into the function of LRRK2 focused on its enzymatic activities4-6. Although a clear picture has yet to emerge of a consistent alteration in these due to mutations, data from a number of groups has highlighted the importance of the kinase activity of LRRK2 in cell death linked to mutations7,8. Recent publications have reported inhibitors targeting the kinase activity of LRRK2, providing a key experimental tool9-11. In light of these data, it is likely that the enzymatic properties of LRRK2 afford us an important window into the biology of this protein, although whether they are potential drug targets for Parkinson's is open to debate.
A number of different approaches have been used to assay the kinase activity of LRRK2. Initially, assays were carried out using epitope tagged protein overexpressed in mammalian cell lines and immunoprecipitated, with the assays carried out using this protein immobilised on agarose beads4,5,7. Subsequently, purified recombinant fragments of LRRK2 in solution have also been used, for example a GST tagged fragment purified from insect cells containing residues 970 to 2527 of LRRK212. Recently, Dani&euml;ls et al. reported the isolation of full length LRRK2 in solution from human embryonic kidney cells, however this protein is not widely available13. In contrast, the GST fusion truncated form of LRRK2 is commercially available (from Invitrogen, see table 1 for details), and provides a convenient tool for demonstrating an assay for LRRK2 kinase activity. Several different outputs for LRRK2 kinase activity have been reported. Autophosphorylation of LRRK2 itself, phosphorylation of Myelin Basic Protein (MBP) as a generic kinase substrate and phosphorylation of an artificial substrate - dubbed LRRKtide, based upon phosphorylation of threonine 558 in Moesin - have all been used, as have a series of putative physiological substrates including &alpha;-synuclein, Moesin and 4-EBP14-17. The status of these proteins as substrates for LRRK2 remains unclear, and as such the protocol described below will focus on using MBP as a generic substrate, noting the utility of this system to assay LRRK2 kinase activity directed against a range of potential substrates.

Assaying the Kinase Activity of LRRK2 in vitro

Leucine Rich Repeat Kinase 2 is a large multidomain kinase, mutations in which are the most common genetic cause of Parkinson's disease. Analysis of the kinase activity of this protein has proven to be a crucial tool in understanding the biology and dysfunction of this protein. In this paper, in vitro assaying of the kinase activity of LRRK2 and a selection of its mutants is described, providing an experimental system to examine phosphorylation of putative substrates and potential dysfunction of LRRK2 in disease.

LRRK2의 키나제 활동 시금 체외에서</em

Leucine Rich Repeat Kinase 2 (LRRK2) is a 2527 amino acid member of the ROCO family of proteins, possessing a complex, multidomain structure including a ...

Identification of Post-translational Modifications of Plant Protein Complexes

Plants adapt quickly to changing environments due to elaborate perception and signaling systems. During pathogen attack, plants rapidly respond to infection via the recruitment and activation of immune complexes. Activation of immune complexes is associated with post-translational modifications (PTMs) of proteins, such as phosphorylation, glycosylation, or ubiquitination. Understanding how these PTMs are choreographed will lead to a better understanding of how resistance is achieved.
Here we describe a protein purification method for nucleotide-binding leucine-rich repeat (NB-LRR)-interacting proteins and the subsequent identification of their post-translational modifications (PTMs). With small modifications, the protocol can be applied for the purification of other plant protein complexes. The method is based on the expression of an epitope-tagged version of the protein of interest, which is subsequently partially purified by immunoprecipitation and subjected to mass spectrometry for identification of interacting proteins and PTMs.
This protocol demonstrates that: i). Dynamic changes in PTMs such as phosphorylation can be detected by mass spectrometry; ii). It is important to have sufficient quantities of the protein of interest, and this can compensate for the lack of purity of the immunoprecipitate; iii). In order to detect PTMs of a protein of interest, this protein has to be immunoprecipitated to get a sufficient quantity of protein.

We describe here a protocol for the purification and characterization of plant protein complexes. We demonstrate that by immunoprecipitating a single protein within a complex, so we can identify its post-translational modifications and its interacting partners.

식물 단백질 복합체의 번역 후 변형의 확인

Plants adapt quickly to changing environments due to elaborate perception and signaling systems. During pathogen attack, plants rapidly respond to ...

Identification of Kinase-substrate Pairs Using High Throughput Screening

We have developed a screening platform to identify dedicated human protein kinases for phosphorylated substrates which can be used to elucidate novel signal transduction pathways. Our approach features the use of a library of purified GST-tagged human protein kinases and a recombinant protein substrate of interest. We have used this technology to identify MAP/microtubule affinity-regulating kinase 2 (MARK2) as the kinase for a glucose-regulated site on CREB-Regulated Transcriptional Coactivator 2 (CRTC2), a protein required for beta cell proliferation, as well as the Axl family of tyrosine kinases as regulators of cell metastasis by phosphorylation of the adaptor protein ELMO. We describe this technology and discuss how it can help to establish a comprehensive map of how cells respond to environmental stimuli.

Protein phosphorylation is a central feature of how cells interpret and respond to information in their extracellular milieu. Here, we present a high throughput screening protocol using kinases purified from mammalian cells to rapidly identify kinases that phosphorylate a substrate(s) of interest.

높은 처리량 검열을 사용 키나제 기판 쌍의 식별


We have developed a screening platform to identify dedicated human protein kinases for phosphorylated substrates which can be used to elucidate novel ...

Experimental Approaches to Study Mitochondrial Localization and Function of a Nuclear Cell Cycle Kinase, Cdk1

Although mitochondria possess their own transcriptional machinery, merely 1% of mitochondrial proteins are synthesized inside the organelle. The nuclear-encoded proteins are transported into mitochondria guided by their mitochondria targeting sequences (MTS); however, a majority of mitochondrial localized proteins lack an identifiable MTS. Nevertheless, the fact that MTS can instruct proteins to go into the mitochondria provides a valuable tool for studying mitochondrial functions of normally nuclear and/or cytoplasmic proteins. We have recently identified the cell cycle kinase CyclinB1/Cdk1 complex in the mitochondria. To specifically study the mitochondrial functions of this complex, mitochondrial overexpression and knock-down of this complex without interfering with its nuclear or cytoplasmic functions were essential. By tagging CyclinB1/Cdk1 with MTS, we were able to achieve mitochondrial overexpression of this complex to study its mitochondrial targets as well as functions. Via tagging dominant-negative Cdk1 with MTS, inhibition of Cdk1 activity was accomplished particularly in the mitochondria. Potential mitochondrial targets of CyclinB1/Cdk1 complex were identified using a gel-based proteomics approach. Unlike traditional 2D gel analysis, we employed 2-dimensional difference gel electrophoresis (2D-DIGE) technology followed by phosphoprotein staining to fluorescently label differentially phosphorylated proteins in mitochondrial Cdk1 expressing cells. Identification of phosphoprotein spots that were altered in wild type versus dominant negative Cdk1 bearing mitochondria revealed the identity of mitochondrial targets of Cdk1. Finally, to determine the effect of CyclinB1/Cdk1 mitochondrial localization in cell cycle progression, a cell proliferation assay using a synthetic thymidine analogue EdU (5-ethynyl-2&#8242;-deoxyuridine) was used to monitor the cells as they go through the cell cycle and replicate their DNA. Altogether, we demonstrated a variety of approaches available to study mitochondrial localization and activity of a cell cycle kinase. These are advanced, yet easy to follow methods that will be beneficial to many cell biology researchers.

Here, we outline how to study mitochondrial localization of a (cell cycle) kinase, and how to determine its sub-mitochondrial location as well as potential mitochondrial substrates/targets. Forced expression of proteins into the mitochondria provides a useful tool for studying the functional consequences of mitochondrial localization of a protein of interest.

 종속 키 1의 시험관에서 키에 의해 인 산화 특정 사이트 분석 결과

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