1. Protein kinase A type I activates a CRE-element more efficiently than protein kinase A type II regardless of C subunit isoform
- Author
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Sigurd Ørstavik, Anne-Katrine Kvissel, Sissel Eikvar, Anja C. V. Larsen, Øystein Stakkestad, and Bjørn Steen Skålhegg
- Subjects
Protein subunit ,lcsh:Animal biochemistry ,Cyclic AMP-Dependent Protein Kinase Type II ,Response Elements ,CREB ,Biochemistry ,lcsh:Biochemistry ,Genes, Reporter ,Cyclic AMP ,Cyclic AMP Response Element-Binding Protein ,Humans ,Protein Isoforms ,lcsh:QD415-436 ,Luciferases ,Protein kinase A ,lcsh:QP501-801 ,Molecular Biology ,Regulation of gene expression ,Reporter gene ,biology ,HEK 293 cells ,Subcellular localization ,Cell biology ,Cyclic AMP-Dependent Protein Kinase Type I ,HEK293 Cells ,Gene Expression Regulation ,biology.protein ,Protein Binding ,Research Article - Abstract
Background Protein kinase A type I (PKAI) and PKAII are expressed in most of the eukaryotic cells examined. PKA is a major receptor for cAMP and specificity is achieved partly through tissue-dependent expression and subcellular localization of subunits with different biochemical properties. In addition posttranslational modifications help fine tune PKA activity, distribution and interaction in the cell. In spite of this the functional significance of two forms of PKA in one cell has not been fully determined. Here we have tested the ability of PKAI and PKAII formed by expression of the regulatory (R) subunits RIα or RIIα in conjunction with Cα1 or Cβ2 to activate a co-transfected luciferace reporter gene, controlled by the cyclic AMP responsive element-binding protein (CREB) in vivo. Results We show that PKAI when expressed at equal levels as PKAII was significantly (p < 0.01) more efficient in inducing Cre-luciferace activity at saturating concentrations of cAMP. This result was obtained regardless of catalytic subunit identity. Conclusion We suggest that differential effects of PKAI and PKAII in inducing Cre-luciferace activity depend on R and not C subunit identity.
- Published
- 2011