TRIM32 is an E3 ubiquitin ligase for dysbindin.
TRIM32 is an E3 ubiquitin ligase for dysbindin.
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DOI：
10.1093/hmg/ddp167
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发表时间：
2009-07-01
影响因子：
3.5
通讯作者：
Blake DJ
中科院分区：
文献类型：
--
作者：
Locke M;Tinsley CL;Benson MA;Blake DJ
编码三方基序蛋白32(TRIM32)的基因突变导致两种看似不同的疾病：肢带型2H肌营养不良症(LGMD2H)或肌管性肌病(STM)和Bardet-Biedl综合征11型(BBS11)。尽管TRIM32与蛋白质泛素化有关，但人们对其底物和致病突变的分子后果知之甚少。在本文中，我们证明了TRIM32是一种广泛表达的泛素连接酶，定位于骨骼肌的Z线。使用酵母双杂交系统，我们发现TRIM32结合并泛素化dybindin，这是一种与精神分裂症的遗传病因有关的蛋白质，增加了它的降解。小干扰RNA介导的TRIM32在成肌细胞中的敲除导致了异常结合蛋白水平的升高。重要的是，与LGMD2H/STM相关的TRIM32突变D487N和R394H会削弱泛素连接酶对debindin的活性，并且在异源细胞中被错误定位。这些突变体能够在转基因细胞中与野生型TRIM32进行自结合和免疫共沉淀。此外，D487N突变株能同时与debindin及其E2酶结合，但在单素化方面存在缺陷。相比之下，BBS11突变体P130S与野生型蛋白相比没有表现出任何生化差异。我们的数据证明TRIM32是一个异常结合蛋白的调节因子，并表明LGMD2H/STM突变可能会损害底物泛素化。
Mutations in the gene encoding tripartite motif protein 32 (TRIM32) cause two seemingly diverse diseases: limb-girdle muscular dystrophy type 2H (LGMD2H) or sarcotubular myopathy (STM) and Bardet–Biedl syndrome type 11(BBS11). Although TRIM32 is involved in protein ubiquitination, its substrates and the molecular consequences of disease-causing mutations are poorly understood. In this paper, we show that TRIM32 is a widely expressed ubiquitin ligase that is localized to the Z-line in skeletal muscle. Using the yeast two-hybrid system, we found that TRIM32 binds and ubiquitinates dysbindin, a protein implicated in the genetic aetiology of schizophrenia, augmenting its degradation. Small-interfering RNA-mediated knock-down of TRIM32 in myoblasts resulted in elevated levels of dysbindin. Importantly, the LGMD2H/STM-associated TRIM32 mutations, D487N and R394H impair ubiquitin ligase activity towards dysbindin and were mislocalized in heterologous cells. These mutants were able to self-associate and also co-immunoprecipitated with wild-type TRIM32 in transfected cells. Furthermore, the D487N mutant could bind to both dysbindin and its E2 enzyme but was defective in monoubiquitination. In contrast, the BBS11 mutant P130S did not show any biochemical differences compared with the wild-type protein. Our data identify TRIM32 as a regulator of dysbindin and demonstrate that the LGMD2H/STM mutations may impair substrate ubiquitination.
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DOI：
10.1073/pnas.0600158103
发表时间：
2006-04-18
影响因子：
11.1
作者：
Chiang, AP;Beck, JS;Sheffield, VC
通讯作者：
Sheffield, VC
影响因子：
4.7
作者：
Horn, EJ;Albor, A;Kulesz-Martin, M
通讯作者：
Kulesz-Martin, M
影响因子：
30.8
作者：
Avela, K;Lipsanen-Nyman, M;Lehesjoki, AE
通讯作者：
Lehesjoki, AE
影响因子：
3.3
作者：
Campbell, Edward M.;Dodding, Mark P.;Hope, Thomas J.
通讯作者：
Hope, Thomas J.
影响因子：
2
作者：
Moore, SJ;Green, JS;Parfrey, PS
通讯作者：
Parfrey, PS