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Steroidogenic acute regulatory protein expression is dependent upon post-translational effects of cAMP-dependent protein kinase A.
- Source :
-
Molecular and cellular endocrinology [Mol Cell Endocrinol] 2001 Feb 28; Vol. 173 (1-2), pp. 183-92. - Publication Year :
- 2001
-
Abstract
- Tropic hormones acutely stimulate adrenal and gonadal steroidogenesis by activation of the cAMP-dependent protein kinase A (PKA) signaling pathway and subsequent induction of Steroidogenic Acute Regulatory (StAR) protein (StAR) expression. We present a comparative study of StAR regulation in mouse adrenocortical Y1 and the derived PKA mutant Kin-8 cell lines to evaluate the PKA requirement for StAR expression. A parallel increase in StAR steady-state mRNA and protein was observed in Y1 cells. StAR mRNA was induced in 8-Br-cAMP-treated Kin-8 cells with maximal expression levels approx. 50% of that observed in Y1 cells. However, a corresponding increase in StAR protein, as detected by Western analysis, was absent in the Kin-8 cells. A similar distribution of StAR mRNA in active polysome fractions was observed for both 8-Br-cAMP-treated Y1 and Kin-8 cells, as well as a 2-fold increase in incorporation of [35S]methionine into StAR, which indicated translation was not blocked in Kin-8 cells. Together these data indicate that PKA functions at the post-translational level to regulate StAR expression and we propose that phosphorylation of StAR by PKA contributes to protein stability
- Subjects :
- 8-Bromo Cyclic Adenosine Monophosphate pharmacology
Animals
Blotting, Western
Cell Line
Cholesterol Side-Chain Cleavage Enzyme genetics
Cyclic AMP-Dependent Protein Kinases antagonists & inhibitors
Isoquinolines pharmacology
Mice
Molecular Sequence Data
Phosphoproteins biosynthesis
Phosphoproteins genetics
Phosphorylation drug effects
Precipitin Tests
RNA, Messenger genetics
RNA, Messenger metabolism
Steroidogenic Acute Regulatory Protein
Cyclic AMP-Dependent Protein Kinases metabolism
Gene Expression Regulation drug effects
Phosphoproteins metabolism
Protein Processing, Post-Translational drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 0303-7207
- Volume :
- 173
- Issue :
- 1-2
- Database :
- MEDLINE
- Journal :
- Molecular and cellular endocrinology
- Publication Type :
- Academic Journal
- Accession number :
- 11223189
- Full Text :
- https://doi.org/10.1016/s0303-7207(00)00410-x