Open AccessValproic acid‐mediated transcriptional regulation of human GM3 synthase (hST3Gal V) in SK‐N‐BE(2)‐C human neuroblastoma cells 1
Author(s) -
KWON Hawyoung,
KANG Namyoung,
DAE Hyunmi,
KIM Kyoungsook,
KIM Cheorlho,
DO Suil,
LEE Youngchoon
Publication year - 2008
Publication title -
acta pharmacologica sinica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.514
H-Index - 90
eISSN - 1745-7254
pISSN - 1671-4083
DOI - 10.1111/j.1745-7254.2008.00847.x
Subject(s) - microbiology and biotechnology , neuroblastoma , creb , biology , messenger rna , promoter , luciferase , gene expression , gene , transcriptional regulation , downregulation and upregulation , transcription factor , cell culture , chemistry , transfection , biochemistry , genetics
Aim: To investigate whether valproic acid (VPA) modulates human GM3 synthase (hST3Gal V) mRNA expression, as a part of ganglioside GM3 biosynthesis, in human neuroblastoma cells. Methods: Using RT‐PCR and immunofluo‐rescent confocal microscopy, we examined hST3 Gal V mRNA and GM3 levels during VPA‐induced differentiation of human neuroblastoma SK‐N‐BE(2)‐C cells. We characterized the VPA‐inducible promoter region within the hST3‐Gal V gene using luciferase constructs carrying 5′‐deletions of the hST3Gal V promoter. Results: RT‐PCR indicated that VPA‐mediated hST3 Gal V induction is transcriptionally regulated. Functional analysis of the 5′‐flanking region of the hST3Gal V gene demonstrated that the ‐177 to ‐83 region, which contains a cAMP‐responsive element (CRE) at ‐143, functions as the VPA‐inducible promoter by actively binding CRE binding protein (CREB). In addition, site‐directed mutagenesis and electrophoretic mobility shift assay indicated that the CRE at ‐143 is crucial for the VPA‐induced expression of hST3Gal V in SK‐N‐BE(2)‐C cells. Conclusion: Our results isolated the core promoter region in the hST3 Gal V promoter, a CRE at ‐143, and demonstrated that it is essential for transcriptional activation of hST3Gal V in VPA‐induced SK‐N‐BE(2)‐C cells. Subsequent CREB binding to this CRE mediates VPA‐dependent upregulation of hST3 Gal V gene expression.