Poly(C) binding protein family is a transcription factor in mu-opioid receptor gene expression.
The mouse mu-opioid receptor (MOR) gene has two promoters, referred to as distal and proximal promoter. Previously, our colleagues reported that a 26-base pair (bp) cis-acting element of the mouse MOR gene activates MOR gene expression. Here, we report the cloning of four members of the poly(C) binding protein (PCBP) family and show that the 26-bp polypyrimidine stretch in MOR proximal promoter interacts with these PCBPs and activates MOR transcription. The PCBPs bind not only to single-stranded but also to double-stranded DNA. The nuclear run-off assay and semiquantitative RT-PCR shows that PCBPs enhance the transcription rate of MOR gene. Furthermore, we performed refined mapping to elucidate the core region (-317/-304) involved in mediating the PCBP-induced MOR promoter activity. Decoy oligonucleotides against the polypyrimidine stretch inhibit the PCBP-induced MOR promoter activity, thereby reconfirming the role of this element in regulating MOR promoter activity. Chromatin immunoprecipitation assay confirmed the interaction of PCBPs with MOR promoter in vivo. In conclusion, we demonstrate that PCBPs act as a transcription factor and positively regulate MOR gene expression in NMB cells.
Kim
Sung-Su
SS
Department of Pharmacology, University of Minnesota Medical School, 6-120 Jackson Hall, 321 Church St. SE, Minneapolis, MN 55455, USA. kimxx558@umn.edu
Pandey
Krishan K
KK
Choi
Hack Sun
HS
Kim
Seong-Youl
SY
Law
Ping-Yee
PY
Wei
Li-Na
LN
Loh
Horace H
HH
D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D045744:Cell Line, Tumor; D003001:Cloning, Molecular; D017931:DNA Primers; D004268:DNA-Binding Proteins; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D051379:Mice; D011066:Poly C / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D034741:RNA, Small Interfering / Q000378:metabolism; D016601:RNA-Binding Proteins; D017450:Receptors, Opioid, mu / Q000235:genetics*; D014157:Transcription Factors / Q000378:metabolism / Q000502:physiology*
D002352:Carrier Proteins; D017931:DNA Primers; D004268:DNA-Binding Proteins; C121375:Pcbp1 protein, mouse; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; D017450:Receptors, Opioid, mu; D014157:Transcription Factors; D011066:Poly C