Open AccessHormonal Regulation of an Islet-Specific Enhancer in the Pancreatic Homeobox Gene STF-1
Author(s) -
Seema D. Sharma,
Ulupi S. Jhala,
Tracy Johnson,
Kevin Ferreri,
Janet L. Leonard,
Marc Montminy
Publication year - 1997
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.17.5.2598
Subject(s) - biology , enhancer , homeobox , pax4 , islet , homeobox a1 , gene expression , microbiology and biotechnology , regulation of gene expression , endocrinology , medicine , pancreas , gene , pancreatic islets , genetics , insulin
The homeobox protein STF-1 appears to function as a master control switch for expression of the pancreatic program during development. Here we characterize a composite enhancer which directs STF-1 expression to pancreatic islet cells via two functional elements that recognize the nuclear factors HNF-3beta and BETA-2. In keeping with their inhibitory effects on islet cell maturation, glucocorticoids were found to repress STF-1 gene expression by interfering with HNF-3beta activity on the islet-specific enhancer. Overexpression of HNF-3beta suppressed glucocorticoid receptor-mediated inhibition of the STF-1 gene, and our results suggest that the expansion of pancreatic islet precursor cells during development may be restricted by hormonal cues which regulate STF-1 gene expression.