Author(s): Seasholtz AF, Gamm DM, Ballestero RP, Scarpetta MA, Uhler MD. Differential expression of mRNAs for protein kinase inhibitor isoforms in mouse brain. Proc Natl Acad Sci U S A. 1995 Feb 28;92(5):1734-8.
Journal: Proceedings Of The National Academy Of Sciences Of The United States Of America, Volume 92, Issue 5, Feb 1995
Many neurotransmitters are known to regulate neuronal cell function by means of activation of cAMP-dependent protein kinase (PKA) and phosphorylation of neuronal substrate proteins, including transcription factors and ion channels. Here, we have characterized the gene expression of two isoforms of a protein kinase inhibitor (PKI) specific for PKA in mouse brain by RNase protection and in situ hybridization histochemistry. The studies demonstrate that the PKI alpha isoform is abundant in many regions of the adult mouse brain but particularly in cerebellum, hypothalamus, hippocampus, and cortex. In contrast, PKI beta is present at much lower levels in most brain regions but is found in significant amounts in the cerebellum, as well as in distinct nuclei within the pons, medulla, and hypothalamus. These results are consistent with a regulatory role of endogenous PKI in PKA-mediated signal transduction in brain and suggest differential functions for the two isoforms of PKI within the central nervous system.