Open AccesshDREF Regulates Cell Proliferation and Expression of Ribosomal Protein Genes
Author(s) -
Daisuke Yamashita,
Yukako Sano,
Yuka Adachi,
Yuma Okamoto,
Hiroyuki Osada,
Takashi Takahashi,
Tomohiro Yamaguchi,
Takashi Osumi,
Fumiko Hirose
Publication year - 2007
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.01462-06
Subject(s) - biology , gene knockdown , chromatin immunoprecipitation , gene , microbiology and biotechnology , gene expression , ribosomal protein , transcription factor , transcription (linguistics) , electrophoretic mobility shift assay , cell growth , regulation of gene expression , promoter , transcriptional regulation , rna , genetics , ribosome , linguistics , philosophy
Although ribosomal proteins (RPs) are essential cellular constituents in all living organisms, mechanisms underlying regulation of their gene expression in mammals remain unclear. We have established that 22 out of 79 human RP genes contain sequences similar to the human DREF (DNA replication-related element-binding factor; hDREF) binding sequence (hDRE) within 200-bp regions upstream of their transcriptional start sites. Electrophoretic gel mobility shift assays and chromatin immunoprecipitation analysis indicated that hDREF binds to hDRE-like sequences in the RP genes both in vitro and in vivo. In addition, transient luciferase assays revealed that hDRE-like sequences act as positive elements for RP gene transcription and cotransfection of an hDREF-expressing plasmid was found to stimulate RP gene promoter activity. Like that of hDREF, expression of RP genes is increased during the late G1 to S phases, and depletion of hDREF using short hairpin RNA-mediated knockdown decreased RP gene expression and cell proliferation in normal human fibroblasts. Knockdown of the RPS6 gene also resulted in impairment of cell proliferation. These data suggest that hDREF is an important transcription factor for cell proliferation which plays roles in cell cycle-dependent regulation of a number of RP genes.