Department of Biochemistry and Molecular Biology, The Key Laboratory of Neurobiology and Vascular Biology, China.
Biochem Biophys Res Commun. 2013 Jun 28;436(2):162-8. doi: 10.1016/j.bbrc.2013.05.067. Epub 2013 May 31.
The Krüppel-like factor 4 is a DNA-binding transcriptional regulator that regulates a diverse array of cellular processes, including development, differentiation, proliferation, and apoptosis. The previous studies about KLF4 functions mainly focused on its role as a transcription factor, its functions in the cytoplasm are still unknown. In this study, we found that PDGF-BB could prompt the translocation of KLF4 to the cytoplasm through CRM1-mediated nuclear export pathway in vascular smooth muscle cells (VSMCs) and increased the interaction of KLF4 with actin in the cytoplasm. Further study showed that both KLF4 phosphorylation and SUMOylation induced by PDGF-BB participates in regulation of cytoskeletal organization by stabilizing the actin cytoskeleton in VSMCs. In conclusion, these results identify that KLF4 participates in the cytoskeletal organization by stabilizing cytoskeleton in the cytoplasm of VSMCs.
Krüppel 样因子 4 是一种 DNA 结合转录调节因子，可调节多种细胞过程，包括发育、分化、增殖和凋亡。先前关于 KLF4 功能的研究主要集中在其作为转录因子的作用上，其在细胞质中的功能尚不清楚。在这项研究中，我们发现在血管平滑肌细胞（VSMCs）中，血小板衍生生长因子-BB（PDGF-BB）可以通过 CRM1 介导的核输出途径促使 KLF4 易位到细胞质中，并增加 KLF4 与细胞质中肌动蛋白的相互作用。进一步的研究表明，PDGF-BB 诱导的 KLF4 磷酸化和 SUMO 化参与了细胞骨架的调节，通过稳定 VSMCs 中的肌动蛋白细胞骨架来稳定细胞骨架。总之，这些结果表明 KLF4 通过稳定 VSMCs 细胞质中的细胞骨架参与细胞骨架的组织。
