Autoradiographic localization of particulate cyclic amp-dependent protein kinase in mammalian brain using[3H] cyclic AMP: Implications for organization of second messenger systems

Abstract

Cyclic AMP's regulatory role as an intracellular second messenger is well established. In brain and other tissues, specific proteins that bind cyclic AMP have been shown to be the regulatory subunits of cystolic and particulate cyclic AMP-dependent protein kinases. This study of the autoradiographic localization of specific [3H]cyclic AMP binding revealed the heterogeneous distribution of particualte cyclic AMP-dependent protein kinase in the mammalian central nervous system. Specific [3H]cyclic AMP binding to tissue sections was of high affinity (KD = 60 nM) and saturable (Bmax= 5 pmol/mg protein). Purine and pyrimidine nucleotide analogues demonstrated inhibition constants against [3H]cycl..