RNA binding protein QKI contributes to WT1 mRNA and suppresses apoptosis in ST cells

The RNA binding protein quaking (QKI), a key member of the STAR family, as an upstream gene could involve in much process including cell proliferation, apoptosis, differentiation and so on. However, the roles of QKI in germ cell, especially in swine testis (ST) cells, was not clear currently. And apoptosis plays important roles in the growth and development. The purpose of the present study was to clarify the relationship between QKI and apoptosis in ST cells. Firstly, our results showed that pEF1α-QKI and shQKI3 have clear effects on expression levels of QKI. Secondly, we established that QKI directly binds to WT1 3′UTR by binding with QRE-1 (2046–2052 bp, ACTAAC) only. Furthermore, QKI overexpression significantly increased the expression levels of WT1 and Bcl-2. QKI also has the effect on delaying the degradation of WT1 mRNA. In addition, we verified that QKI had a significantly suppressed apoptosis in ST cells. Finally, pBI-WT1 could make up for shQKI3-induced decrease in WT1, Bcl-2 mRNA levels and suppress apoptosis in ST cells. The results demonstrated that QKI was an important regulatory factor that affects apoptosis by targeting WT1 gene.