死孢子体1
自噬
信号转导衔接蛋白
细胞生物学
生物
袋3
泛素
信号转导
支架蛋白
转录因子
生物化学
基因
细胞凋亡
作者
Junyan Shi,Jerry Wong,Paulina Piesik,Gabriel Fung,Jingchun Zhang,Julienne Jagdeo,Xiaotao Li,Eric Jan,Honglin Luo
出处
期刊:Autophagy
[Informa]
日期:2013-10-25
卷期号:9 (10): 1591-1603
被引量:102
摘要
The adaptor protein, sequestosome 1 (SQSTM1)/p62, plays an essential role in mediating selective autophagy. It serves as an autophagy receptor targeting ubiquitinated proteins to autophagosomes for degradation. In addition, it functions as a scaffold protein to regulate signaling pathways. Here we explored the interplay between coxsackievirus B3 (CVB3) and SQSTM1-mediated selective autophagy. We reported that SQSTM1 was cleaved at glycine 241 following CVB3 infection through the activity of viral protease 2Apro. The resulting cleavage fragments of SQSTM1 were no longer the substrates of autophagy, and their ability to form protein aggregates was greatly decreased. Although the C-terminal truncation sustained the binding activity of SQSTM1 to microtubule-associated protein 1 light chain (LC3), it failed to interact with ubiquitinated proteins. It was also found that colocalization between the C-terminal fragment of SQSTM1 (SQSTM1-C) and LC3 and ubiquitin within the punctate structures was markedly disrupted. Moreover, we observed that SQSTM1-C retained the ability of SQSTM1 to stabilize antioxidant transcription factor NFE2L2 [nuclear factor (erythroid-derived 2)-like 2]; however, both the N-terminal fragment of SQSTM1 (SQSTM1-N) and SQSTM1-C lost the function of SQSTM1 in activating NFKB (the nuclear factor of kappa light polypeptide gene enhancer in B-cells) pathway. Collectively, our results suggest a novel model by which cleavage of SQSTM1 as a result of CVB3 infection impairs the function of SQSTM1 in selective autophagy and host defense signaling.
科研通智能强力驱动
Strongly Powered by AbleSci AI