Enterocyte differentiation marker intestinal alkaline phosphatase is a target gene of the gut-enriched Krüppel-like factor

Brian F. Hinnebusch, Aleem Siddique, J. Welles Henderson, Madhu S. Malo, Wenying Zhang, Christopher P. Athaide, Mario A. Abedrapo, Xinming Chen, Vincent W. Yang, Richard A. Hodin

Research output: Contribution to journalArticlepeer-review

96 Scopus citations

Abstract

We have examined the role that the transcription factor gut-enriched Krüppel-like factor (KLF4 or GKLF) plays in activating the enterocyte differentiation marker gene intestinal alkaline phosphatase (IAP). A yeast one-hybrid screen was used to identify proteins interacting with a previously identified cis-element (IF-III) located within the human IAP gene promoter. DNA-protein interactions were determined by using EMSA. Northern blot analysis was used to study RNA expression in human colon cancer RKO cells engineered to overexpress KLF4. Transient transfections with IAP-luciferase reporter constructs were used to characterize the mechanisms by which KLF4 activates IAP transcription. The yeast one-hybrid screen and EMSA identified KLF4 as binding to IF-III. RKO cells induced to overexpress KLF4 demonstrated a corresponding dose-dependent increase in IAP expression, and EMSA with nuclear extract from these cells confirmed that KLF4 binds to the IF-III element. Transient transfections revealed that KLF4 transactivated the IAP gene largely via a critical segment in the IAP promoter that includes the IF-III cis-element. Mutant KLF4 constructs failed to fully activate IAP. We have identified the enterocyte differentiation marker IAP as a KLF4 target gene. IAP transactivation by KLF4 is likely mediated through a critical region located within the proximal IAP promoter region.

Original languageEnglish (US)
Pages (from-to)G23-G30
JournalAmerican Journal of Physiology - Gastrointestinal and Liver Physiology
Volume286
Issue number1 49-1
DOIs
StatePublished - Jan 2004

Keywords

  • Gene regulation
  • Intestine
  • Transcription factor

ASJC Scopus subject areas

  • Physiology
  • Hepatology
  • Gastroenterology
  • Physiology (medical)

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