Name: isolating potentiated hsp104 variants using yeast proteinopathy models
Uploaded: 2014-11-11T14:00:00.000+00:00
Duration: 8 min 44 s
Description: Watch this Scientific Journal Video about Isolating Potentiated Hsp104 Variants Using Yeast Proteinopathy Models at JoVE.com

We thank Sue Lindquist, Aaron Gitler, and Martin Duennwald for kindly sharing reagents. Our studies were supported by: an American Heart Association Post-Doctoral Fellowship (M.E.J); NIH Director's New Innovator Award DP2OD002177, NIH grants R21NS067354, R21HD074510, and R01GM099836, a Muscular Dystrophy Association Research Award (MDA277268), Packard Center for ALS Research at Johns Hopkins University, Target ALS, and an Ellison Medical Foundation New Scholar in Aging Award (J.S.).

1. 도서관 생성 <ol><li> 도메인 별 오류가 발생하기 쉬운 PCR 사용 Hsp104의 라이브러리를 구성하려면 먼저 오류가 발생하기 쉬운 DNA 중합 효소 (20) 관심의 영역을 증폭. </li><li> 겔을 추출하여 PCR 생성물을 정제 하였다. </li><li> 표준 부위 지정 돌연변이 유발 프로토콜을 사용 megaprimer 확장 단계를 수행하여 PCR 완충액 50 ng의 템플릿 플라스미드 250 겨 megaprimer, 200 μM의 dNTPs 및 고성능 DNA 중합 효소를 결합하고, PCR 등급의 물 (20)과 50 ㎕의 총 부피로 희석 . 표준 PCR 프로그램을 실행합니다. NOTE : 증폭되는 유전자의 특정 지역에 따라 달라질 사용될 특정 프라이머. <ol><li> PCR에 이어, 37 ° C에서 2 시간 동안 1 ㎕의 DPN I 제한 효소로 부모 주형 DNA를 소화. </li></ol></li><li> ultracompetent E.에서 전기 또는 다른 수단에 의해 라이브러리 변환 대장균 미니 프렙하여 정제하고. 참고 : 라이브러리 생성실질적으로 주어진 실험의 목적에 따라 달라집니다. Hsp104 매우 큰 단백질이므로 우리가 특정 도메인 에러 유발 PCR을 이용하는 이유는 전체 유전자를 랜덤 비실용적이다. 또한 Hsp104의 구조는 저조한 21 도전 관한 라이브러리 디자인을 이해 남아. 라이브러리 유일한 제한은 템플릿 플라스미드 백본 스트로스 미디어 -5- FOA 카운터의 선택을 허용하는 URA3 유전자를 포함해야한다는 점 이외에는, 돌연변이 유발에 관한 랜덤 접근 방식을 사용하여 구성 될 수있다. </li></ol> Hsp104 도서관 2. 변환 <ol><li> 표준 리튬 아세테이트 / PEG 변환 프로토콜 (22)를 사용하여 W303aΔ의 hsp104 효모에 질병 관련 기판을 통합 할 수 있습니다. 하나의 식민지를 선택하고, 기판 (23)을 관련 질병의 높은 독성을 가진 균주를 분리 독성을 화면. 참고 : 통합 변형 및 솔라를 사용하여모든 셀에 동일한 발현을 보장하기 위해 단일 ​​콜로니 테. pAG416GAL 플라스미드 (우라실 마커) (24)로 우라실 이외 마커 (우리는 히스티딘 사용) Hsp104 라이브러리 하에서 유전자의 통합을 허용하는 플라스미드로 질병 기판을 복제. 5-FOA의 counterselection을 허용하기 위해 라이브러리가 우라실 마커와 플라스미드로부터 발현되어 있는지 확인합니다. 다른 효모 균주도 사용될 수있다. 우리는 W303a 모두 WT와 Δ hsp104 배경에 BY4741 효모 균주 (MEJ과 JS, 관찰되지 않은)을 사용하여 유사한 독성 억제 표현형을 언급했다. </li><li> 동일한 리튬 아세테이트 / PEG 변환 프로토콜 (22)을 사용하여이 균주에 Hsp104 라이브러리 변형. 라이브러리의 시퀀스 공간을 유지하고 예측 된 라이브러리 크기를 유지하기 위해 적절히 변형 배율 확대. </li><li> 충분히 판을 사용하여 noninducing, 선택적 플레이트 상에 변환 혼합물 (예 : SD-그의 우라)를 플레이트콜로니 다수의 성장을 보장한다. 필요한 접시의 수를 최소화하기 위해 큰 배양 접시 (150mm)를 사용합니다. 플레이트를 사용하여 형질 전환 체를 복구하는 것은 변환 효율을 평가 할 수 있습니다. </li><li> 병렬 Hsp104 WT 및 벡터 음성 대조군 변환. </li></ol> Proteotoxicity의 억제를위한 3. 심사 <ol><li> 피노 오스 보충 드롭 아웃 미디어 (예 : SRaff-그의 우라)를 사용하여 판 오프 식민지를 씻으십시오. 접시에서 식민지를 풀어 혈청 학적 피펫 멸균 나무 어플리케이터를 사용합니다. 50 ML 원뿔 튜브와 소용돌이에 액체 세척을 이동하는 것은 철저히 세포의 덩어리를 분리합니다. 약간 흐린 문화, OD 600 ~ 0.025로 희석. 참고 : 여기 라 피노 오스 따라서 갈락토스 매개 유도 세포를 프라이밍, 유도의 포도당 매개 억압의 세포를 완화하는 역할을한다. </li><li> 3에서 진탕 피노 오스 드롭 아웃 미디어에서 하룻밤 희석 문화를 성장0 ºC. 병렬 Hsp104 WT 및 벡터 제어를 성장. </li><li> 다음날 아침, 개인 갈락토스 위에 농도의 범위를 판 (예 SGal-그의 우라) 판 (400 μL 총 볼륨 문화를 집중 2 ml의 1 μL). 농도의 넓은 범위를 도금하는 것은 접시가 하나의 식민지있을 것이라는 점을 보장합니다. 필요한 실제 농도는 관심있는 질병 기판의 독성에 의존한다. </li><li> 라이브러리의 OD 600 벡터 및 Hsp104 WT 문화를 정상화하고 컨트롤 라이브러리 상대적인 성장을 비교하는 같은 부피를 접시. </li><li> 선택의 엄격 성을 평가하기 위해, 미디어 (억압) 포도당에 라이브러리를 접시. 식민지 (그림 2) 나타날 때까지, 30 ºC 2-3 일 동안 번호판을 품어. 그 결과 식민지를 평가하고 컨트롤에 비교합니다. NOTE : 종종 모두 크고 작은 콜로니가 수득되지만, 콜로니 크기와 행동 사이에 상관 관계의 ivity가 관찰된다. 시퀀싱 이월 가양 최소화 -5- FOA 카운터 선택 기술 (단계 4)를 사용하여 이러한 잠재적 히트 화면. </li></ol> 4. 5-FOA Counterselection 스포팅는 오판 가능성을 제거하기 위해 <ol><li> 단일 및 이중 드롭 아웃 매체에 중복 된 단일 콜로니 (예 : SD-그의 우라과 SD-그의 판) 30 ºC에서 하룻밤 성장 밖으로 행진. 벡터 및 Hsp104 WT 컨트롤을 반복합니다. 도금 SD-그의 종래 5-FOA들은 5-FOA에 도금되는 경우 세포 Hsp104 플라스미드를 상실한 가능성을 증가시켜 5-FOA 단계의 효율을 증가시킨다. </li><li> 5 FOA 화면을 수행하는 동안 마르지 판을 방지하기 위해, 4 ºC에서 SD-그의 우라의 파라 필름에 접시와 저장소를 포장. 이 판은 결국 시퀀싱에 사용됩니다. </li><li> 행진에서 식민지 SD-그의 5-FOA 플레이트에 하나의 식민지 판 (YPD 미디어 + 1g / L 5-FOA) 및 (30)에서 1~2 일 동안 배양# 186; C는 하나의 식민지가 나타날 때까지. 여기서, 5-FOA는 URA3 유전자를 포함하는 세포에서의 독성 생성물 (5-fluorodeoxyuridine)로 변환된다. 따라서, 여전히 Hsp104 플라스미드를 보유하는 모든 세포는 죽을 것이다. </li><li> 행진 SD 우라과 SD-그의 접시 위에 중복의 5-FOA 판에서 하나의 식민지. 각 테스트 3 식민지는 각각의 히트에 대해 적어도 하나의 식민지가 Hsp104 플라스미드를 상실 할 가능성을 증가했다. 30 ° C에서 1~2 일 동안 품어. SD-번호판하지만 SD 우라 판에 성장합니다 Hsp104 플라스미드를 잃은 식민지. </li><li> 분석을 안보에 대한 Hsp104 플라스미드를 잃은 균주​​를 성장. 진탕 30 ºC에서 하룻밤 (96) DeepWell 2 ml의 판에 (예를 들어 SRaff-그의) 라 피노 오스 드롭 아웃 미디어에서 포화 균주를 성장. 5 FOA 처리 제어 계통을 포함해야합니다. </li><li> 분석을 안보에 대 한 번호판을 준비합니다. 멀티 채널 피펫을 사용하여, 나누어지는 200 μL 피노 오스 드롭 아웃 미디어 (예 : SRaff-그의) 당96 웰 플레이트의 잘, 예약 열 깔끔한 문화 1, 7. 나누어지는 250 열 1에 16 포화 문화의 각 μL 및 플레이트 7. </li><li> 직렬 멀티 채널 피펫 철저하게 혼합, 플레이트의 각 열에 문화 5 배 희석. 각 웰의 최종 부피를 위해 컬럼 (6) 및 (12)로부터 희석 배양의 50 μl를 제거하여 200 μL이다. 이것은 심지어 안보 보장하기 위해 필수적이다. </li><li> 96 볼트 복제 도구 (Frogger와)를 사용하여 SD-그의 및 SGal-그의 판에 중복의 문화를 발견. 2~3일 30 ºC에서 번호판을 품어. </li><li> 컨트롤 유사한 SGal-그의 플레이트에 독성을 나타내는 균주를 시퀀싱을 위해 선택한다. 컨트롤로 유독하지 않음으로 오탐 (false positive) 균주를 폐기하십시오. 5-FOA는 그 자체로 종종 독성, 그래서 혼자 질병 기판보다 SD-그의 접시에 성장 결함 또는 전시 실질적으로 더 큰 독성을 나타내는 균주를 (폐기 <stronG&gt; 그림 3). </li></ol> 5. 식민지 PCR에 의해 Hsp104 변종을 시퀀싱 <ol><li> 다 쳤어요 ~ 10 μL의 PCR 스트립 관에서 3 μL 20 mM의 NaOH를에서 SD-그의 우라 판에서 효모와 동결 - 해동하여 세포를 용해. 다음 10 분 동안 열 순환기에서 99 ºC에서 부화, 10 분 동안 또는 액체 질소 -80 ºC 냉동고에서 스트립 튜브를 놓습니다. PCR 등급 물 100 μL에 균주를 희석. </li><li> PCR 반응 준비 : 5 μL PCR 템플릿, 0.5 μL 100 μm의 각 프라이머, 0.5 μl의 10 mM이의 dNTPs, PCR 버퍼 0.25 μL DNA 중합 효소를, 그리고 PCR 등급 물 25 μL 총 볼륨으로 구성한다. 디자인 프라이머는 무작위 지역 플러스 양쪽 끝에서 약 100 bp의 증폭합니다. 성공적인 증폭의 가능성을 증가시키기 위해 증폭 된 영역의 크기를 최소화한다. 표준 PCR 프로그램을 실행합니다. </li><li> 적절한 SIZ의 PCR 생성물의 증폭을 확인하기 위해, 아가 로스 겔 전기 영동에 의해 시료를 분석전자. 어떤 제품이 존재하지 않는 경우 PCR을 반복한다. NOTE : PCR 장애가 통상적 단계 5.1에서 사용되는 너무 많은 효모 때문이다. </li><li> DNA 시퀀싱 샘플을 준비합니다. 이러한 엑소 뉴 클레아 I와 새우 알칼리 포스 파타 아제 효소로 PCR 정화 또는 PCR 제품 정리 시약을 사용하여 하나 PCR 프라이머를 제거 (ExoSAP-IT)의 단일 가닥 DNA를 분해합니다. 이 시약은 효소 높은 처리량을 허용, 비법 인 프라이머 및 dNTPs를 저하됩니다. </li><li> PCR 제품 시퀀싱. 철저하게 돌연변이 염기 서열 크로마토 그램을 분석해야합니다. 종종 여러 플라스미드 항구 효모로 돌연변이는, 특정 사이트 (그림 4)에서 두 개의 뉴클레오티드의 혼합물로 관찰 할 수있다. </li></ol>

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E., 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=Operational+Plasticity+Enables+Hsp104+to+Disaggregate+Diverse+Amyloid+and+Nonamyloid+Clients.">Operational Plasticity Enables Hsp104 to Disaggregate Diverse Amyloid and Nonamyloid Clients.</a> Cell. 151 (4), 778-793 (2012).</li><li>Jackrel, M. E., 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=Potentiated+Hsp104+Variants+Antagonize+Diverse+Proteotoxic+Misfolding+Events.">Potentiated Hsp104 Variants Antagonize Diverse Proteotoxic Misfolding Events.</a> Cell. 156 (1-2), 170-182 (2014).</li><li>Wittrup, K. D., Verdine, G. L., Wittrup, K. D., Verdine, G. 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> Methods in Enzymology. 503, 13-14 (2012).</li><li>Boeke, J. D., Trueheart, J., Natsoulis, G., Fink, G. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Methods in Enzymology. 154, 164-175 (1987).</li><li>Miyazaki, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Creating+Random+Mutagenesis+Libraries+by+Megaprimer+PCR+of+Whole+Plasmid+(MEGAWHOP).+Directed+Evolution+Library+Creation:+Methods+in+Molecular+Biology.">Creating Random Mutagenesis Libraries by Megaprimer PCR of Whole Plasmid (MEGAWHOP). Directed Evolution Library Creation: Methods in Molecular Biology.</a> eds FrancesH Arnold &amp; George Georgiou. 231, 23-28 (2003).</li><li>Saibil, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chaperone+machines+for+protein+folding,+unfolding+and+disaggregation.">Chaperone machines for protein folding, unfolding and disaggregation.</a> Nat Rev Mol Cell Biol. 14 (10), 630-642 (2013).</li><li>Gietz, R. D., Schiestl, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-efficiency+yeast+transformation+using+the+LiAc/SS+carrier+DNA/PEG+method.">High-efficiency yeast transformation using the LiAc/SS carrier DNA/PEG method.</a> Nat. Protocols. 2 (1), 31-34 (2007).</li><li>Armakola, M., Hart, M. P., Gitler, A. 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The authors have nothing to disclose.

여기에서 우리는 효모 proteinopathy 모델을 사용하여 질병 관련 기판의 독성을 억제하는 효력을 더 Hsp104 변종을 분리에 대한 우리의 접근 방식을 제시한다. 이 방법을 사용하여, 변형의 큰 라이브러리 만 제한 -5- FOA 보조 스크린을 통과 변이체의 개수 인 상태, 높은 처리량 스크리닝 할 수있다. 96 웰 형식으로 다음 단계를 수행함으로써, 우리는 정기적으로 1-2주의 과정을 통해 5-FOA 단계에서 한 번에 2...

효모 proteinopathy 모델은 근 위축성 측삭 경화증 (ALS) 및 파킨슨 병 (PD) 1-3 포함한 단백질 미스 폴딩 장애 개발되어왔다. ALS 환자에서 misfold 단백질 TDP-43 및 FUS,의 발현은, 효모 1, 2에서 세포질 응집체를 형성하는 독성 및 mislocalize 있습니다. 마찬가지로, PD에 연루되어 α - 시누 클레인 (α-SYN)의 표현은, 독성 및 mislocalizes 효모 3 세포질 응집체를 형성 할 수 있습니다. 이러한 기능은 이러한 장애 4,5 환자의 표현형을 요점을 되풀이. 따라서, 효모 모델을 방지하거나 이러한 표현형 2,6-13 역 단백질이나 작은 분자 스크리닝을위한 유용한 플랫폼을 제공합니다. 저자들은 TDP-43, FUS 및 α-SYN에 집계 및 독성을 반전 할 수있는 단백질의 개발에 관심이 있습니다. 우리는 Hsp104, 모두 FR 단백질을 disaggregating의 고유 할 수있는 효모에서 AAA + 단백질에 초점효모에서 톰 비정질 단위 및 아밀로이드는 아직 더 인간의 상동 (14, 15)이 없습니다. Hsp104 미세 내생 효모 프리온을들을 분해하도록 조정하고 일반적으로 16, 17가 발생하지 인간의 신경 퇴행성 질환에 연루 기판을들을 분해하는 제한된 능력을 가지고 있습니다. 따라서, 우리는 efficaciously이 인간의 기판을들을 분해 할 수있는 Hsp104의 향상된 버전을 설계하는 것을 목표로하고 있습니다. Hsp104는 오류가 발생하기 쉬운 PCR을 사용하여 변형이를 위해, 우리는 큰 라이브러리를 구성; 이 라이브러리는 효모 proteinopathy 모델 (17)를 사용하여 검사를 할 수 있습니다. Hsp104 (17) 매우 큰 것처럼 우리는 라이브러리를 구성하고 심사에 도메인 타겟 접근 방식을 채택했습니다. 유사한 접근법이 다른 도메인을 선별하기 위해 사용될 수 있지만 우리는 처음, 중간 도메인 Hsp104 17 (MD)에 집중했다. 예컨대, 나머지는 표면 디스플레이, 같은 대체 기술과 반대로 이러한 모델은, 직접적 disaggregase 활성 스크리닝 에이블18 바인딩 모니터링을위한 사용하기 ricted. 우리의 프로토콜은 두 심사 단계 (그림 1)을 기반으로합니다. 첫째, 효모 질병 기판의 독성을 억제 Hsp104 변이체가 선택된다. 이렇게하려면 Hsp104 변종과 질병 관련 기판은 Δ의 hsp104 효모에 cotransformed된다. 우리는 야생 형의 부재 (WT) Hsp104 17 Hsp104 시퀀스 공간을 탐험 Δ의 hsp104 효모를 사용합니다. 중요한 것은, Hsp104의 삭제는 효모의 α-SYN, FUS, 또는 TDP-43 독성에 영향을주지 않으며, Hsp104 (WT)의 표현은 최소한의 구조 1,13,17을 제공합니다. 효모는 양쪽 단백질의 발현을 유도하는 유도 배양액에 도금된다. 식민지의 질병 관련 기판 협의 성장의 독성을 억제 Hsp104 변종을 품고 효모. 식민지 독성 다이를 억제하지 않는 변종을 유지하면서 이러한 변형은, 추가 분석을 위해 선택됩니다. 그러나,오탐 (false positive)이 화면에 상당한 문제가 있습니다. TDP-43, FUS 및 α-SYN의 식으로 표현되는 Hsp104 변형과 관련이없는 독성의 자발적인 유전자 억제의 모양에 대한 강력한 선택적 압력을 생성하는, 매우 독성이 있습니다. 따라서, 우리는 이러한 비특이적 독성 억제 (17)를 제거하기 위해 상대적으로 높은 처리량입니다 보조 화면을 사용했다. 이 보조 화면에서 선택 효모 Hsp104 플라스미드 (19)에 대한 선택에 대응하기 위해 5 Fluorootic 산 (5-FOA)로 처리된다. 균주 후 기판의 독성 Hsp104 플라스미드의 손실 후 복원 될 수 있도록 분석을 통해 안보 (TDP-43, FUS, 또는 α-SYN) 독성 기판에 대한 평가된다. 따라서, 독성이 보조 화면에 복원되는 효모는 아마도 원래 인해 Hsp104 변종의 존재에 대한 독성 억제를 표시. 이러한 효모 &#39;히트&#39;로 표시되고 Hsp104 플라스미드는되어야회수 Hsp104 유전자 17 (도 1)의 변이를 식별하는 서열. 모든 히트 곡은 다음 독성 억제에 대한 재검사 후 독립적으로 돌연변이를 구성하는 부위 특이 적 변이를 사용하여 재확인해야한다. 이 프로토콜에 대한 잠재적 인 응용 프로그램은 광범위하다. 이러한 방법을 이용하여 단백질의 임의의 타입의 라이브러리가 효모의 독성 어떤 기질 단백질의 독성을 억제하는 변형에 대해 스크리닝 될 수있다.

<table><tbody><tr><td>GeneMorphII EZClone Domain Mutagenesis Kit</td><td>Agilent</td><td>200552</td><td></td></tr><tr><td>150 mm Petri dishes</td><td>Falcon</td><td>351058</td><td></td></tr><tr><td>5-Fluorootic Acid</td><td>Research Products International</td><td>f10501-5.0</td><td></td></tr><tr><td>96-DeepWell 2 ml Plates</td><td>Eppendorf</td><td>0030 502.302</td><td></td></tr><tr><td>96 bold replicator tool</td><td>V&amp;amp;P Scientific</td><td>vp-404</td><td></td></tr><tr><td>ExoSAP-IT</td><td>Affymetrix</td><td>78200</td><td></td></tr></tbody></table>

isolating potentiated hsp104 variants using yeast proteinopathy models

Many protein-misfolding disorders can be modeled in the budding yeast Saccharomyces cerevisiae. Proteins such as TDP-43 and FUS, implicated in amyotrophic lateral sclerosis, and &#945;-synuclein, implicated in Parkinson&#8217;s disease, are toxic and form cytoplasmic aggregates in yeast. These features recapitulate protein pathologies observed in patients with these disorders. Thus, yeast are an ideal platform for isolating toxicity suppressors from libraries of protein variants. We are interested in applying protein disaggregases to eliminate misfolded toxic protein conformers. Specifically, we are engineering Hsp104, a hexameric AAA+ protein from yeast that is uniquely capable of solubilizing both disordered aggregates and amyloid and returning the proteins to their native conformations. While Hsp104 is highly conserved in eukaryotes and eubacteria, it has no known metazoan homologue. Hsp104 has only limited ability to eliminate disordered aggregates and amyloid fibers implicated in human disease. Thus, we aim to engineer Hsp104 variants to reverse the protein misfolding implicated in neurodegenerative disorders. We have developed methods to screen large libraries of Hsp104 variants for suppression of proteotoxicity in yeast. As yeast are prone to spontaneous nonspecific suppression of toxicity, a two-step screening process has been developed to eliminate false positives. Using these methods, we have identified a series of potentiated Hsp104 variants that potently suppress the toxicity and aggregation of TDP-43, FUS, and &#945;-synuclein. Here, we describe this optimized protocol, which could be adapted to screen libraries constructed using any protein backbone for suppression of toxicity of any protein that is toxic in yeast.

우리는 중간 영역에서 무작위 Hsp104 변종의 라이브러리를 구축하고 TDP-43 독성 억제를 위해 그것을 상영했다​​. 도서관은 변화와 화면의 엄격 성을 평가하기 위해 포도당과 갈락토스 판 (그림 2)에 도금. 단일 콜로니를 선택하고, 균주 카운터 Hsp104 플라스미드를 제거하기 위해 5-FOA를 사용하여 선정되었다. 이 균주는 그 독성을 확인하기 위해 평가되었다 것은 Hsp104 변종 않고, TDP-43 형...

Watch this Scientific Journal Video about Isolating Potentiated Hsp104 Variants Using Yeast Proteinopathy Models at JoVE.com

Isolating Potentiated Hsp104 Variants Using Yeast Proteinopathy Models

Yeast proteinopathy models are valuable tools to assess the toxicity and aggregation of proteins implicated in disease. Here, we present methods for screening Hsp104 variant libraries for toxicity suppressors. This protocol could be adapted to screen any protein library for toxicity suppressors of any protein that is toxic in yeast.

효력을 더 Hsp104 변종 사용 효모 Proteinopathy 모델을 분리

Many protein-misfolding disorders can be modeled in the budding yeast Saccharomyces cerevisiae. Proteins such as TDP-43 and FUS, implicated in amyotrophic ...

isolating-potentiated-hsp104-variants-using-yeast-proteinopathy-models

Research

JoVE Journal

Biology

8.1K 조회수.  Perelman School of Medicine at the University of Pennsylvania. Yeast proteinopathy models are valuable tools to assess the toxicity and aggregation of proteins implicated in disease. Here, we present methods for screening Hsp104 variant libraries for toxicity suppressors. This protocol could be adapted to screen any protein library for toxicity suppressors of any protein that is toxic in yeast.

비디오: Isolating Potentiated Hsp104 Variants Using Yeast Proteinopathy Models

Yeast As a Chassis for Developing Functional Assays to Study Human P53

The finding that the well-known mammalian P53 protein can act as a transcription factor (TF) in the yeast S. cerevisiae has allowed for the development of different functional assays to study the impacts of 1) binding site [i.e., response element (RE)] sequence variants on P53 transactivation specificity or 2) TP53 mutations, co-expressed cofactors, or small molecules on P53 transactivation activity. Different basic and translational research applications have been developed. Experimentally, these approaches exploit two major advantages of the yeast model. On one hand, the ease of genome editing enables quick construction of qualitative or quantitative reporter systems by exploiting isogenic strains that differ only at the level of a specific P53-RE to investigate sequence-specificity of P53-dependent transactivation. On the other hand, the availability of regulated systems for ectopic P53 expression allows the evaluation of transactivation in a wide range of protein expression. Reviewed in this report are extensively used systems that are based on color reporter genes, luciferase, and the growth of yeast to illustrate their main methodological steps and to critically assess their predictive power. Moreover, the extreme versatility of these approaches can be easily exploited to study different TFs including P63 and P73, which are other members of TP53 gene family.

Presented here are four protocols to construct and exploit yeast Saccharomyces cerevisiae reporter strains to study human P53 transactivation potential, impacts of its various cancer-associated mutations, co-expressed interacting proteins, and the effects of specific small molecules.

인간 P53을 연구하기 위한 기능성 어세이 개발을 위한 섀시로 효모

The finding that the well-known mammalian P53 protein can act as a transcription factor (TF) in the yeast S. cerevisiae has allowed for the development of ...

연구

암 연구학

Characterizing Histone Post-translational Modification Alterations in Yeast Neurodegenerative Proteinopathy Models

Neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) and Parkinson&#39;s disease (PD), cause the loss of hundreds of thousands of lives each year. Effective treatment options able to halt disease progression are lacking. Despite the extensive sequencing efforts in large patient populations, the majority of ALS and PD cases remain unexplained by genetic mutations alone. Epigenetics mechanisms, such as the post-translational modification of histone proteins, may be involved in neurodegenerative disease etiology and progression and lead to new targets for pharmaceutical intervention. Mammalian in vivo and in vitro models of ALS and PD are costly and often require prolonged and laborious experimental protocols. Here, we outline a practical, fast, and cost-effective approach to determining genome-wide alterations in histone modification levels using Saccharomyces cerevisiae as a model system. This protocol allows for comprehensive investigations into epigenetic changes connected to neurodegenerative proteinopathies that corroborate previous findings in different model systems while significantly expanding our knowledge of the neurodegenerative disease epigenome.

This protocol outlines experimental procedures to characterize genome-wide changes in the levels of histone post-translational modifications (PTM) occurring in connection with the overexpression of proteins associated with ALS and Parkinson&#39;s disease in Saccharomyces cerevisiae models. After SDS-PAGE separation, individual histone PTM levels are detected with modification-specific antibodies via Western blotting.

효 모 신경 Proteinopathy 모델에서 특성화 히스톤 포스트 번역 상 수정 변경

Neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) and Parkinson&#39;s disease (PD), cause the loss of hundreds of thousands of lives ...

유전학

A Comparative Approach to Characterize the Landscape of Host-Pathogen Protein-Protein Interactions

Significant efforts were gathered to generate large-scale comprehensive protein-protein interaction network maps. This is instrumental to understand the pathogen-host relationships and was essentially performed by genetic screenings in yeast two-hybrid systems. The recent improvement of protein-protein interaction detection by a Gaussia luciferase-based fragment complementation assay now offers the opportunity to develop integrative comparative interactomic approaches necessary to rigorously compare interaction profiles of proteins from different pathogen strain variants against a common set of cellular factors.
This paper specifically focuses on the utility of combining two orthogonal methods to generate protein-protein interaction datasets: yeast two-hybrid (Y2H) and a new assay, high-throughput Gaussia princeps protein complementation assay (HT-GPCA) performed in mammalian cells.
A large-scale identification of cellular partners of a pathogen protein is performed by mating-based yeast two-hybrid screenings of cDNA libraries using multiple pathogen strain variants. A subset of interacting partners selected on a high-confidence statistical scoring is further validated in mammalian cells for pair-wise interactions with the whole set of pathogen variants proteins using HT-GPCA. This combination of two complementary methods improves the robustness of the interaction dataset, and allows the performance of a stringent comparative interaction analysis. Such comparative interactomics constitute a reliable and powerful strategy to decipher any pathogen-host interplays.

This article focuses on the identification of high-confident interaction datasets between host and pathogen proteins using a combination of two orthogonal methods: yeast two-hybrid followed by a high-throughput interaction assay in mammalian cells called HT-GPCA.

호스트 병원체 단백질 - 단백질 상호 작용의 풍경의 특성을 비교 접근

Significant efforts were gathered to generate  large-scale comprehensive protein-protein interaction network maps. This is  instrumental to understand the ...

면역학 및 감염병학

Genetic Studies of Human DNA Repair Proteins Using Yeast as a Model System 

Understanding the roles of human DNA repair proteins in genetic pathways is a formidable challenge to many researchers. Genetic studies in mammalian systems have been limited due to the lack of readily available tools including defined mutant genetic cell lines, regulatory expression systems, and appropriate selectable markers. To circumvent these difficulties, model genetic systems in lower eukaryotes have become an attractive choice for the study of functionally conserved DNA repair proteins and pathways. We have developed a model yeast system to study the poorly defined genetic functions of the Werner syndrome helicase-nuclease (WRN) in nucleic acid metabolism. Cellular phenotypes associated with defined genetic mutant backgrounds can be investigated to clarify the cellular and molecular functions of WRN through its catalytic activities and protein interactions. The human WRN gene and associated variants, cloned into DNA plasmids for expression in yeast, can be placed under the control of a regulatory plasmid element. The expression construct can then be transformed into the appropriate yeast mutant background, and genetic function assayed by a variety of methodologies. Using this approach, we determined that WRN, like its related RecQ family members BLM and Sgs1, operates in a Top3-dependent pathway that is likely to be important for genomic stability. This is described in our recent publication [1] at <a href="http://www.impactaging.com">www.impactaging.com</a>. Detailed methods of specific assays for genetic complementation studies in yeast are provided in this paper.

Genetic Studies of Human DNA Repair Proteins Using Yeast as a Model System

Genetic studies in yeast can be employed to investigate the molecular and cellular functions of human genes in cellular DNA metabolism. Methods are described for the genetic characterization of the human WRN gene product defective in the premature aging disorder Werner syndrome in functionally conserved pathways using yeast as a tractable model system.

인간의 DNA 수리 단백질의 유전자 연구는 모델 시스템으로 효모를 사용하여

Understanding the roles of human DNA repair proteins in genetic pathways is a formidable challenge to many researchers.  Genetic studies in mammalian ...

생물학

Purification of Hsp104, a Protein Disaggregase

Hsp104 is a hexameric AAA+ protein1 from yeast, which couples ATP hydrolysis to protein disaggregation2-10 (Fig. 1). This activity imparts two key selective advantages. First, renaturation of disordered aggregates by Hsp104 empowers yeast survival after various protein-misfolding stresses, including heat shock3,5,11,12. Second, remodeling of cross-beta amyloid fibrils by Hsp104 enables yeast to exploit myriad prions (infectious amyloids) as a reservoir of beneficial and heritable phenotypic variation13-22. Remarkably, Hsp104 directly remodels preamyloid oligomers and amyloid fibrils, including those comprised of the yeast prion proteins Sup35 and Ure223-30. This amyloid-remodeling functionality is a specialized facet of yeast Hsp104. The E. coli orthologue, ClpB, fails to remodel preamyloid oligomers or amyloid fibrils26,31,32.
Hsp104 orthologues are found in all kingdoms of life except, perplexingly, animals. Indeed, whether animal cells possess any enzymatic system that couples protein disaggregation to renaturation (rather than degradation) remains unknown33-35. Thus, we and others have proposed that Hsp104 might be developed as a therapeutic agent for various neurodegenerative diseases connected with the misfolding of specific proteins into toxic preamyloid oligomers and amyloid fibrils4,7,23,36-38. There are no treatments that directly target the aggregated species associated with these diseases. Yet, Hsp104 dissolves toxic oligomers and amyloid fibrils composed of alpha-synuclein, which are connected with Parkinson's Disease23 as well as amyloid forms of PrP39. Importantly, Hsp104 reduces protein aggregation and ameliorates neurodegeneration in rodent models of Parkinson's Disease23 and Huntington's disease38. Ideally, to optimize therapy and minimize side effects, Hsp104 would be engineered and potentiated to selectively remodel specific aggregates central to the disease in question4,7. However, the limited structural and mechanistic understanding of how Hsp104 disaggregates such a diverse repertoire of aggregated structures and unrelated proteins frustrates these endeavors30,40-42.
To understand the structure and mechanism of Hsp104, it is essential to study the pure protein and reconstitute its disaggregase activity with minimal components. Hsp104 is a 102kDa protein with a pI of ~5.3, which hexamerizes in the presence of ADP or ATP, or at high protein concentrations in the absence of nucleotide43-46. Here, we describe an optimized protocol for the purification of highly active, stable Hsp104 from E. coli. The use of E. coli allows simplified large-scale production and our method can be performed quickly and reliably for numerous Hsp104 variants. Our protocol increases Hsp104 purity and simplifies His6-tag removal compared to a previous purification method from E. coli47. Moreover, our protocol is more facile and convenient than two more recent protocols26,48.

Here, we describe a protocol for the purification of highly active Hsp104, a hexameric AAA+ protein from yeast, which couples ATP hydrolysis to protein disaggregation. This scheme exploits a His6-tagged construct for affinity purification from E. coli followed by anion-exchange chromatography, His6-tag removal with TEV protease, and size-exclusion chromatography.

Hsp104의 정화, 단백질 Disaggregase

Hsp104 is a hexameric AAA+ protein1 from yeast, which couples ATP hydrolysis to protein disaggregation2-10 (Fig. 1). This activity imparts two key ...

Growth Assays to Assess Polyglutamine Toxicity in Yeast

Protein misfolding is associated with many human diseases, particularly neurodegenerative diseases, such as Alzheimer&#x2019;s disease, Parkinson's disease, and Huntington's disease 1. Huntington's disease (HD) is caused by the abnormal expansion of a polyglutamine (polyQ) region within the protein huntingtin. The polyQ-expanded huntingtin protein attains an aberrant conformation (i.e. it misfolds) and causes cellular toxicity 2. At least eight further neurodegenerative diseases are caused by polyQ-expansions, including the Spinocerebellar Ataxias and Kennedy&#x2019;s disease 3.
The model organism yeast has facilitated significant insights into the cellular and molecular basis of polyQ-toxicity, including the impact of intra- and inter-molecular factors of polyQ-toxicity, and the identification of cellular pathways that are impaired in cells expressing polyQ-expansion proteins 3-8. Importantly, many aspects of polyQ-toxicity that were found in yeast were reproduced in other experimental systems and to some extent in samples from HD patients, thus demonstrating the significance of the yeast model for the discovery of basic mechanisms underpinning polyQ-toxicity. 
A direct and relatively simple way to determine polyQ-toxicity in yeast is to measure growth defects of yeast cells expressing polyQ-expansion proteins. This manuscript describes three complementary experimental approaches to determine polyQ-toxicity in yeast by measuring the growth of yeast cells expressing polyQ-expansion proteins. The first two experimental approaches monitor yeast growth on plates, the third approach monitors the growth of liquid yeast cultures using the BioscreenC instrument. 
Furthermore, this manuscript describes experimental difficulties that can occur when handling yeast polyQ models and outlines strategies that will help to avoid or minimize these difficulties. The protocols described here can be used to identify and to characterize genetic pathways and small molecules that modulate polyQ-toxicity. Moreover, the described assays may serve as templates for accurate analyses of the toxicity caused by other disease-associated misfolded proteins in yeast models.

This manuscript describes three complementary protocols for assessing the toxicity of polyglutamine (polyQ)-expansion proteins in the yeast Saccharomyces cerevisiae. These protocols can easily be modified to monitor the toxicity of other misfolded proteins in yeast.

성장 Assays은 효모에서 Polyglutamine 독성을 평가하기 위해

Protein misfolding is associated with many human diseases, particularly neurodegenerative diseases, such as Alzheimer&#x2019;s disease, Parkinson's ...

Coupled Assays for Monitoring Protein Refolding in Saccharomyces cerevisiae

Proteostasis, defined as the combined processes of protein folding/biogenesis, refolding/repair, and degradation, is a delicate cellular balance that must be maintained to avoid deleterious consequences 1. External or internal factors that disrupt this balance can lead to protein aggregation, toxicity and cell death. In humans this is a major contributing factor to the symptoms associated with neurodegenerative disorders such as Huntington's, Parkinson's, and Alzheimer's diseases 10. It is therefore essential that the proteins involved in maintenance of proteostasis be identified in order to develop treatments for these debilitating diseases. This article describes techniques for monitoring in vivo protein folding at near-real time resolution using the model protein firefly luciferase fused to green fluorescent protein (FFL-GFP). FFL-GFP is a unique model chimeric protein as the FFL moiety is extremely sensitive to stress-induced misfolding and aggregation, which inactivates the enzyme 12. Luciferase activity is monitored using an enzymatic assay, and the GFP moiety provides a method of visualizing soluble or aggregated FFL using automated microscopy. These coupled methods incorporate two parallel and technically independent approaches to analyze both refolding and functional reactivation of an enzyme after stress. Activity recovery can be directly correlated with kinetics of disaggregation and re-solubilization to better understand how protein quality control factors such as protein chaperones collaborate to perform these functions. In addition, gene deletions or mutations can be used to test contributions of specific proteins or protein subunits to this process. In this article we examine the contributions of the protein disaggregase Hsp104 13, known to partner with the Hsp40/70/nucleotide exchange factor (NEF) refolding system 5, to protein refolding to validate this approach.

Coupled Assays for Monitoring Protein Refolding in Saccharomyces cerevisiae

This article describes the use of a firefly luciferase-GFP fusion protein to investigate in vivo protein folding in Saccharomyces cerevisiae. Using this reagent, refolding of a model heat-denatured protein can be monitored simultaneously by fluorescence microscopy and an enzymatic assay to probe the roles of proteostasis network components in protein quality control.

의 모니터링 단백질 접힘에 대한 결합 분석 실험<em&gt; 사카 cerevisiae의</em

Proteostasis, defined as the combined processes of protein folding/biogenesis, refolding/repair, and degradation, is a delicate cellular balance that must ...

Genetic and Biochemical Approaches for In Vivo and In Vitro Assessment of Protein Oligomerization: The Ryanodine Receptor Case Study

Oligomerization is often a structural requirement for proteins to accomplish their specific cellular function. For instance, tetramerization of the ryanodine receptor (RyR) is necessary for the formation of a functional Ca2+ release channel pore. Here, we describe detailed protocols for the assessment of protein self-association, including yeast two-hybrid (Y2H), co-immunoprecipitation (co-IP) and chemical cross-linking assays. In the Y2H system, protein self-interaction is detected by &#946;-galactosidase assay in yeast co-expressing GAL4 bait and target fusions of the test protein. Protein self-interaction is further assessed by co-IP using HA- and cMyc-tagged fusions of the test protein co-expressed in mammalian HEK293 cells. The precise stoichiometry of the protein homo-oligomer is examined by cross-linking and SDS-PAGE analysis following expression in HEK293 cells. Using these different but complementary techniques, we have consistently observed the self-association of the RyR N-terminal domain and demonstrated its intrinsic ability to form tetramers. These methods can be applied to protein-protein interaction and homo-oligomerization studies of other mammalian integral membrane proteins.

Genetic and Biochemical Approaches for In Vivo and In Vitro Assessment of Protein Oligomerization: The Ryanodine Receptor Case Study

Oligomerization of the ryanodine receptor, a homo-tetrameric ion channel mediating Ca2+ release from intracellular stores, is critical for skeletal and cardiac muscle contraction. Here, we present complementary in vivo and in vitro methods to detect protein self-association and determine homo-oligomer stoichiometry.

대한 유전 및 생화학 적 접근<em&gt; 생체</em&gt; 및<em&gt; 체외</em&gt; 단백질 올리고머의 평가 다음 Ryanodine 수용체 사례 연구

Oligomerization is often a structural requirement for proteins to accomplish their specific cellular function. For instance, tetramerization of the ...

High-throughput Screening for Protein-based Inheritance in S. cerevisiae

The encoding of biological information that is accessible to future generations is generally achieved via changes to the DNA sequence. Long-lived inheritance encoded in protein conformation (rather than sequence) has long been viewed as paradigm-shifting but rare. The best characterized examples of such epigenetic elements are prions, which possess a self-assembling behavior that can drive the heritable manifestation of new phenotypes. Many archetypal prions display a striking N/Q-rich sequence bias and assemble into an amyloid fold. These unusual features have informed most screening efforts to identify new prion proteins. However, at least three known prions (including the founding prion, PrPSc) do not harbor these biochemical characteristics. We therefore developed an alternative method to probe the scope of protein-based inheritance based on a property of mass action: the transient overexpression of prion proteins increases the frequency at which they acquire a self-templating conformation. This paper describes a method for analyzing the capacity of the yeast ORFeome to elicit protein-based inheritance. Using this strategy, we previously found that &gt;1% of yeast proteins could fuel the emergence of biological traits that were long-lived, stable, and arose more frequently than genetic mutation. This approach can be employed in high throughput across entire ORFeomes or as a targeted screening paradigm for specific genetic networks or environmental stimuli. Just as forward genetic screens define numerous developmental and signaling pathways, these techniques provide a methodology to investigate the influence of protein-based inheritance in biological processes.

High-throughput Screening for Protein-based Inheritance in S. cerevisiae

This protocol describes a high-throughput methodology to functionally screen for protein-based inheritance in S. cerevisiae.

S. cerevisiae 에 단백질 기반 상속에 대 한 높은 처리량 검열

The encoding of biological information that is accessible to future generations is generally achieved via changes to the DNA sequence. Long-lived ...

A Method to Study &#945;-Synuclein Toxicity and Aggregation Using a Humanized Yeast Model

Parkinson's disease is the second most common neurodegenerative disorder and is characterized by progressive cell death caused by the formation of Lewy bodies containing misfolded and aggregated &#945;-synuclein. &#945;-synuclein is an abundant presynaptic protein that regulates synaptic vesicle trafficking, but the accumulation of its proteinaceous inclusions results in neurotoxicity. Recent studies have revealed that various genetic factors, including bacterial chaperones, could reduce the formation of &#945;-synuclein aggregates in vitro. However, it is also important to monitor the anti-aggregation effect in the cell to apply this as a potential treatment for the patients. It would be ideal to use neuronal cells, but these cells are difficult to handle and take a long time to exhibit the anti-aggregation phenotype. Therefore, a quick and effective in vivo tool is required for the further evaluation of in vivo anti-aggregation activity. The method described here was used to monitor and analyze the anti-aggregation phenotype in the humanized yeast Saccharomyces cerevisiae, which expressed human &#945;-synuclein. This protocol demonstrates in vivo tools that could be used for monitoring &#945;-synuclein-induced cellular toxicity, as well as the formation of &#945;-synuclein aggregates in cells.

An in vivo physiological model of &#945;-synuclein is required to study and understand the pathogenesis of Parkinson's disease. We describe a method to monitor the cytotoxicity and aggregate formation of &#945;-synuclein using a humanized yeast model.

인간화 효모 모델을 이용한 α-시뉴클레인 독성 및 응집을 연구하는 방법

Parkinson's disease is the second most common neurodegenerative disorder and is characterized by progressive cell death caused by the formation of Lewy ...

효력을 더 Hsp104 변종 사용 효모 Proteinopathy 모델을 분리

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