SQSTM1/p62 interacts with FKBP38 and regulates cell cycle in Cashmere goat foetal fibroblasts

SQSTM1 (sequestosome 1, also known as p62) is a multifunctional scaffold protein implicated in diverse cell physiology processes, such as autophagy, cell signalling, and protein turnover. FKBP38 (FK506-binding protein 38) is a member of FKBPs family and plays a key role in various cellular processes, including signalling transduction, embryonic development and apoptosis. In order to explore the role of SQSTM1/p62 gene in cell-cycle progression and proliferation of goat foetal fibroblast (GFbs), SQSTM1/p62 gene was cloned and characterized. Furthermore, the yeast two-hybrid screening system was used to identify the interaction between SQSTM1/p62 and FKBP38. The results suggested that SQSTM1/p62 directly interacts with FKBP38. Overexpression vector pIRES-EGFP-SQSTM1/p62 and shRNA eukaryotic expression vector pRNAT-U6.1-shSQSTM1/p62 which harboured siRNA targeting the SQSTM1/p62 mRNA were constructed. The overexpression of SQSTM1/p62 gene in GFbs significantly increase the S-phase cells compared with control cells (p p Abbreviations: Aba: aureobasidin A; EIF1: eukaryotic translation initiation factor 1; FKBP: FK506-binding protein; FKBP38: FK506-binding protein 38; GFbs: goat foetal fibroblast; mTOR: mammalian target of rapamycin; PDLIM7: PDZ and LIM domain 7; SD: standard dropout; SQSTM1/p62: sequestosome 1SQSTM1（sequestosome 1，又称p62）是一种多功能支架蛋白，参与自噬、细胞信号传导、蛋白质周转等多种细胞生理过程。FKBP38（FK506结合蛋白38，FK506-binding protein 38）属于FKBP家族成员，在信号转导、胚胎发育和细胞凋亡等多种细胞进程中发挥关键作用。为探究SQSTM1/p62基因在山羊胎成纤维细胞（goat foetal fibroblast, GFbs）的细胞周期进程与增殖中的作用，本研究对SQSTM1/p62基因进行了克隆与特征分析。此外，本研究采用酵母双杂交筛选系统，鉴定SQSTM1/p62与FKBP38的相互作用。结果表明，SQSTM1/p62可与FKBP38直接相互结合。本研究构建了过表达载体pIRES-EGFP-SQSTM1/p62，以及携带有靶向SQSTM1/p62 mRNA的小干扰RNA（siRNA）的短发夹RNA（shRNA）真核表达载体pRNAT-U6.1-shSQSTM1/p62。在山羊胎成纤维细胞中过表达SQSTM1/p62基因后，与对照组细胞相比，S期细胞比例显著升高（原文此处“p p”疑似输入笔误）。缩写说明：Aba：金担子素A（aureobasidin A）；EIF1：真核翻译起始因子1（eukaryotic translation initiation factor 1）；FKBP：FK506结合蛋白（FK506-binding protein）；FKBP38：FK506结合蛋白38；GFbs：山羊胎成纤维细胞；mTOR：雷帕霉素靶蛋白（mammalian target of rapamycin）；PDLIM7：PDZ与LIM结构域蛋白7（PDZ and LIM domain 7）；SD：标准缺陷培养基（standard dropout）；SQSTM1/p62：sequestosome 1