Korean J Physiol Pharmacol.  2005 Dec;9(6):333-339.

PKA-Mediated Regulation of B/K Gene Transcription in PC12 Cells

• Choi MH
• Kim HS
• Choi SH
• Kim MY
• Jang YS
• Jang YM
• Lee JH
• Jeong SW
• Kim IK
• Kwon OJ

Abstract

B/K protein is a novel protein containing double C2-like domains. We examined the specific signaling pathway that regulates the transcription of B/K in PC12 cells. When the cells were treated with forskolin (50microM), B/K mRNA and protein levels were time-dependently decreased, reaching the lowest level at 3 or 4 hr, and thereafter returning to the control level. Chemicals such as dibutyryl-cAMP, cell- permeable cyclic AMP (cAMP) analogue and CGS21680, adenosine receptor A2A agonist, also repressed the B/K transcription. However, 1, 9-dideoxyforskolin did not show inhibitory effect on B/K transcription, suggesting direct involvement of cAMP in the forskolin-induced inhibition of B/K transcription. Effect of forskolin, dibutyryl cAMP and CGS21680 was significantly reduced in PKA-deficient PC12 cell line (PC12-123.7). One cAMP-response element (CRE) -like sequence (B/K CLS) was found in the promoter region of B/K DNA, and electrophoretic mobility shift assay indicated its binding to CREM and CREB. Forskolin significantly suppressed the promoter activity in CHO-K1 cells transfected with the constructs containing B/K CLS, but not with the construct in which B/K CLS was mutated (AC: TG). Taken together, we suggest that the transcription of B/K gene in PC12 cells may be regulated by PKA-dependent mechanism.

Keyword

B/K protein; Cyclic AMP; Protein kinase A; PC12 cells; Forskolin; cAMP response element

MeSH Terms

Animals
Colforsin
Cyclic AMP
Cyclic AMP-Dependent Protein Kinases
DNA
Electrophoretic Mobility Shift Assay
PC12 Cells*
Promoter Regions, Genetic
Receptors, Purinergic P1
RNA, Messenger
Colforsin
Cyclic AMP
Cyclic AMP-Dependent Protein Kinases
DNA
RNA, Messenger
Receptors, Purinergic P1