Ubiquilin overexpression reduces GFP-polyalanine-induced protein aggregates and toxicity.
Ubiquilin overexpression reduces GFP-polyalanine-induced protein aggregates and toxicity.
复制标题
泛素过度表达可降低 GFP 聚丙氨酸诱导的蛋白质聚集和毒性。
DOI：
10.1016/j.yexcr.2007.04.006
复制
发表时间：
2007
影响因子：
3.7
通讯作者：
Monteiro,MervynJ
中科院分区：
文献类型：
--
作者：
Wang,Hongmin;Monteiro,MervynJ
Several human disorders are associated with an increase in a continuous stretch of alanine amino acids in proteins. These so-called polyalanine expansion diseases share many similarities with polyglutamine-related disorders, including a length-dependent reiteration of amino acid induction of protein aggregation and cytotoxicity. We previously reported that overexpression of ubiquilin reduces protein aggregates and toxicity of expanded polyglutamine proteins. Here, we demonstrate a similar role for ubiquilin toward expanded polyalanine proteins. Overexpression of ubiquilin-1 in HeLa cells reduced protein aggregates and the cytotoxicity associated with expression of a transfected nuclear-targeted GFP-fusion protein containing 37-alanine repeats (GFP-A37), in a dose dependent manner. Ubiquilin coimmunoprecipitated more with GFP proteins containing a 37-polyalanine tract compared to either 7 (GFP-A7), or no alanine tract (GFP). Moreover, overexpression of ubiquilin suppressed the increased vulnerability of HeLa cell lines stably expressing the GFP-A37 fusion protein to oxidative stress-induced cell death compared to cell lines expressing GFP or GFP-A7 proteins. By contrast, siRNA knockdown of ubiquilin expression in the GFP-A37 cell line was associated with decreased cellular proliferation, and increases in GFP protein aggregates, nuclear fragmentation, and cell death. Our results suggest that boosting ubiquilin levels in cells might provide a universal and attractive strategy to prevent toxicity of proteins containing reiterative expansions of amino acids involved in many human diseases.
