研究發現調控肌萎縮性脊髓側索硬化症的新基因
作者:
小柯機器人發布時間:2019/11/26 15:26:14
美國哈佛大學-麻省理工學院博德研究所Benjamin M. Neale組和Sali M. K. Farhan組合作,在肌萎縮性脊髓側索硬化症(ALS)的外顯子組測序中,發現一種新的熱休克蛋白編碼基因-DNAJC7。11月25日,《自然—神經科學》在線發表了這一成果。
為了發現ALS的新基因,研究人員分析了3,864例病例和7,839個遺傳匹配的對照外顯子組數據。研究人員在ALS病例中觀察到顯著過量的稀有蛋白截短變異體,這些變異集中在受限基因中。
通過基因水平的分析,研究人員測定了已知的ALS基因,如SOD1、NEK1和FUS。研究人員還觀察到高度受限基因DNAJC7中存在多個截然不同的蛋白截短變體。
DNAJC7的信號強度明顯高於全基因組的顯著性,免疫印跡表明,攜帶p.Arg156Ter變體的ALS患者其成纖維細胞中缺少DNAJC7蛋白。DNAJC7編碼熱休克蛋白家族成員HSP40,它與HSP70蛋白合作通過調控新生多肽的摺疊和降解蛋白質的清除來促進蛋白質穩態。
當這些過程不受調控時,細胞內會發生異常蛋白的錯誤摺疊和積累並導致蛋白聚合,這是神經退行性疾病的病理學標誌。該研究揭示了DNAJC7是調控ALS的新基因。
附:英文原文
Title: Exome sequencing in amyotrophic lateral sclerosis implicates a novel gene, DNAJC7 , encoding a heat-shock protein
Author: Sali M. K. Farhan, Daniel P. Howrigan, Liam E. Abbott, Joseph R. Klim, Simon D. Topp, Andrea E. Byrnes, Claire Churchhouse, Hemali Phatnani, Bradley N. Smith, Evadnie Rampersaud, Gang Wu, Joanne Wuu, Aleksey Shatunov, Alfredo Iacoangeli, Ahmad Al Khleifat, Daniel A. Mordes, Sulagna Ghosh, Kevin Eggan, Rosa Rademakers, Jacob L. McCauley, Rebecca Schle, Stephan Zchner, Michael Benatar, J. Paul Taylor, Michael Nalls, Marc Gotkine, Pamela J. Shaw, Karen E. Morrison, Ammar Al-Chalabi, Bryan Traynor, Christopher E. Shaw, David B. Goldstein, Matthew B. Harms, Mark J. Daly, Benjamin M. Neale
Issue&Volume: 2019-11-25
Abstract: To discover novel genes underlying amyotrophic lateral sclerosis (ALS), we aggregated exomes from 3,864 cases and 7,839 ancestry-matched controls. We observed a significant excess of rare protein-truncating variants among ALS cases, and these variants were concentrated in constrained genes. Through gene level analyses, we replicated known ALS genes including SOD1, NEK1 and FUS. We also observed multiple distinct protein-truncating variants in a highly constrained gene, DNAJC7. The signal in DNAJC7 exceeded genome-wide significance, and immunoblotting assays showed depletion of DNAJC7 protein in fibroblasts in a patient with ALS carrying the p.Arg156Ter variant. DNAJC7 encodes a member of the heat-shock protein family, HSP40, which, along with HSP70 proteins, facilitates protein homeostasis, including folding of newly synthesized polypeptides and clearance of degraded proteins. When these processes are not regulated, misfolding and accumulation of aberrant proteins can occur and lead to protein aggregation, which is a pathological hallmark of neurodegeneration. Our results highlight DNAJC7 as a novel gene for ALS.
DOI: 10.1038/s41593-019-0530-0
Source: https://www.nature.com/articles/s41593-019-0530-0