KLF7 promotes preadipocyte proliferation via activation of the Akt signaling pathway by <italic>Cis</italic>-regulating CDKN3
Ziqiu Jia, Jin Zhao, Shu‐Li Shao, Hu Xu, Wen Li, Mahmood Khan, Weiyu Wang, Weiwei Zhang, Yingning Sun
Abstract
<p indent="0mm">Krüppel-like transcription factor 7 (KLF7) promotes preadipocyte proliferation; however, its target gene in this process has not yet been identified. Using KLF7 ChIP-seq analysis, we previously showed that a KLF7-binding peak is present upstream of the cyclin-dependent kinase inhibitor 3 gene ( <italic>CDKN3</italic>) in chicken preadipocytes. In the present study, we identify <italic>CDKN3</italic> as a target gene of KLF7 that mediates the effects of KLF7 on preadipocyte proliferation. Furthermore, 5′-truncating mutation analysis shows that the minimal promoter is located between nt –160 and nt –7 (relative to the translation initiation codon ATG) of <italic>CDKN3</italic>. KLF7 overexpression increases <italic>CDKN3</italic> promoter activity in the DF-1 and immortalized chicken preadipocyte (ICP1) cell lines. Deletion of the putative binding site of KLF7 abolishes the promotive effect of KLF7 overexpression on <italic>CDKN3</italic> promoter activity. Moreover, <italic>CDKN3</italic> knockdown and overexpression assays reveal that <italic>CDKN3</italic> enhances ICP1 cell proliferation. Flow cytometry analysis shows that <italic>CDKN3</italic> accelerates the G1/S transition. Furthermore, we find that KLF7 promotes ICP1 cell proliferation via Akt phosphorylation by regulating <italic>CDKN3</italic>. Taken together, our results suggest that KLF7 promotes preadipocyte proliferation by activating the Akt signaling pathway by <italic>cis</italic>-regulating <italic>CDKN3</italic>, thus driving the G1/S transition.