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

Abstract

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 Sphase cells compared with control cells (p < .05). Furthermore, SQSTM1/p62 gene silencing in GFbs leads to a significant decrease of S-phase cells and cell cycle arrest compared with control cells (p < .05). These data indicate that SQSTM1/p62 gene plays an important role in cell-cycle and proliferation of Cashmere GFbs.