Kruppel Like Factor 4, Gut (KLF4)

Krueppel-like factor 4  acts as a transcriptional activator or repressor depending on the promoter context and/or cooperation with other transcription factors. For example, Klf4 transactivates the iNOS promoter in cooperation with p65 (RelA), and the p21Cip1/Waf1 promoter in cooperation with p53, but it directly suppresses the p53 promoter and inhibits ornithine decarboxylase promoter activity by competing with specificity protein-1 (Sp-1). Klf4 also interacts with the p300/CBP transcription co-activators.KLF4 also contains a potential nuclear localization signal. The human KLF4 protein shares 91% sequence identity with mouse Ezf. Northern blot analysis detected a 3.5-kb KLF4 transcript in RNA from both human umbilical vein endothelial cells and human aortic endothelial cells.