Neuropathy-causing mutations in HSPB1 impair autophagy by disturbing the formation of SQSTM1/p62 bodies
Neuropathy-causing mutations in HSPB1 impair autophagy by disturbing the formation of SQSTM1/p62 bodies
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DOI：
10.1080/15548627.2019.1569930
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发表时间：
2019-06-03
期刊：
影响因子：
13.3
通讯作者：
Timmerman, Vincent
中科院分区：
文献类型：
--
作者：
Haidar, Mansour;Asselbergh, Bob;Timmerman, Vincent
热休克蛋白B 1（heat shock protein family B [small] member 1）是一种广泛表达的分子伴侣。HSPB 1的大多数突变导致轴突Charcot-Marie-Tooth神经病和/或远端遗传性运动神经病。在这项研究中，我们表明，在HSPB 1突变导致损伤的macroautophagic/autophagic流量。在HSPB 1敲除细胞中，我们证明了HSPB 1是自噬体形成所必需的，自噬体在HSPB 1的重新表达后被拯救。对各种HSPB 1变体（野生型和突变体）进行无标记LC-MS/MS分析，我们鉴定了自噬特异性相互作用物。我们揭示了野生型HSPB 1蛋白与自噬受体SQSTM 1/p62结合，SQSTM 1的PB 1结构域对这种相互作用至关重要。HSPB 1突变导致SQSTM 1/p62小体形成减少，随后吞噬细胞形成受损，表明HSPB 1通过与SQSTM 1相互作用在自噬中起调节作用。值得注意的是，自噬缺陷也可以在患者来源的运动神经元中得到证实，从而表明自噬损伤可能是HSPB 1突变导致周围神经病变的病理机制之一。远端遗传性运动神经病; GFP：绿色荧光蛋白; HSPA 8：热休克蛋白家族A（Hsp 70）成员8; HSPB 1/6/8：热休克蛋白家族B（小）成员1/6/8; LIR：LC 3相互作用区; LC 3 B：微管相关蛋白1轻链3 β; PB 1：Phox和Bem 1; SQSTM 1：隔离体1; STUB 1/CHIP：STIP 1同源性和含U盒蛋白1;乌巴：泛素相关; WIPI 1：WD重复结构域，磷酸肌醇相互作用1; WT：野生型
HSPB1 (heat shock protein family B [small] member 1) is a ubiquitously expressed molecular chaperone. Most mutations in HSPB1 cause axonal Charcot-Marie-Tooth neuropathy and/or distal hereditary motor neuropathy. In this study we show that mutations in HSPB1 lead to impairment of macroautophagic/autophagic flux. In HSPB1 knockout cells, we demonstrate that HSPB1 is necessary for autophagosome formation, which was rescued upon re-expression of HSPB1. Employing a label-free LC-MS/MS analysis on the various HSPB1 variants (wild type and mutants), we identified autophagy-specific interactors. We reveal that the wild-type HSPB1 protein binds to the autophagy receptor SQSTM1/p62 and that the PB1 domain of SQSTM1 is essential for this interaction. Mutations in HSPB1 lead to a decrease in the formation of SQSTM1/p62 bodies, and subsequent impairment of phagophore formation, suggesting a regulatory role for HSPB1 in autophagy via interaction with SQSTM1. Remarkably, autophagy deficits could also be confirmed in patient-derived motor neurons thereby indicating that the impairment of autophagy might be one of the pathomechanisms by which mutations in HSPB1 lead to peripheral neuropathy.Abbreviations: ACD: alpha-crystallin domain; ALS: amyotrophic lateral sclerosis; ATG14: autophagy related 14; BAG1/3: BCL2 associated athanogene 1/3; CMT: Charcot-Marie-Tooth; dHMN: distal hereditary motor neuropathy; GFP: green fluorescent protein; HSPA8: heat shock protein family A (Hsp70) member 8; HSPB1/6/8: heat shock protein family B (small) member 1/6/8; LIR: LC3-interacting region; LC3B: microtubule associated protein 1 light chain 3 beta; PB1: Phox and Bem1; SQSTM1: sequestosome 1; STUB1/CHIP: STIP1 homology and U-box containing protein 1; UBA: ubiquitin-associated; WIPI1: WD repeat domain, phosphoinositide interacting 1; WT: wild-type