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Type 2 inositol trisphosphate receptor gene expression in hepatocytes is regulated by cyclic AMP
- Source :
- Biochemical and Biophysical Research Communications. 486:659-664
- Publication Year :
- 2017
- Publisher :
- Elsevier BV, 2017.
-
Abstract
- The type 2 inositol 1,4,5-trisphosphate receptor (IP3R2) is the principal intracellular Ca2+ release channel in hepatocytes, and so is important for bile secretion and other functions. IP3R2 activity is regulated in part by post-translational modifications but little is known about transcriptional regulation of its expression. We found that both IP3R2 mRNA and protein levels in liver were increased during fasting. Treatment of hepatocytes with forskolin or 8-CPT-cAMP also increased IP3R2, and this was reduced by actinomycin D. Analysis of the IP3R2 promoter revealed five CREs, and CREB potently increased promoter activity. Mutation of CRE4 or CRE5 decreased induction by CREB, and ChIP assay showed recruitment of CREB to these sites. Adenylyl cyclase (AC) 6 and 9 were the principal AC isoforms detected in rat hepatocytes, and silencing either one decreased organic anion secretion, which depends on IP3R2. Secretion furthermore was increased by overnight but not acute treatment with forskolin or 8-CPT-cAMP. These findings provide evidence that IP3R2 expression is transcriptionally regulated by cAMP via CREB binding to CRE elements in its promoter. The findings furthermore suggest that this mechanism is relevant for hormonal regulation of bile secretion.
- Subjects :
- Male
0301 basic medicine
Primary Cell Culture
Biophysics
Response Elements
CREB
Biochemistry
Article
Rats, Sprague-Dawley
Adenylyl cyclase
03 medical and health sciences
chemistry.chemical_compound
Gene expression
Cyclic AMP
Transcriptional regulation
Animals
Humans
Inositol 1,4,5-Trisphosphate Receptors
Inositol
Secretion
RNA, Messenger
Promoter Regions, Genetic
Molecular Biology
Binding Sites
Forskolin
biology
Colforsin
Fasting
Hep G2 Cells
Cell Biology
Thionucleotides
Inositol trisphosphate receptor
CREB-Binding Protein
Molecular biology
Rats
030104 developmental biology
Gene Expression Regulation
chemistry
Mutation
Dactinomycin
Hepatocytes
biology.protein
Adenylyl Cyclases
Protein Binding
Signal Transduction
Subjects
Details
- ISSN :
- 0006291X
- Volume :
- 486
- Database :
- OpenAIRE
- Journal :
- Biochemical and Biophysical Research Communications
- Accession number :
- edsair.doi.dedup.....d1baaacc0a48a61e9bed5ce921891998