ADENOSINE 3'-5'-MONOPHOSPHATE RECEPTOR PROTEINS IN MAMMALIAN BRAIN

Abstract

C(cyclic)AMP receptor proteins present in mammalian brain were identified and characterized with the use of the photoaffinity label 8-azido[32P]cAMP. Cytosol and membrane fractions from various regions of rat, guinea pig and bovine brain contained 2 specific cAMP receptor proteins with apparent MW of 47,000 and 52,000-55,000. Subcellular fractionation studies showed the highest amounts of these cAMP receptor proteins associated with cytosol fractions and synaptic membrane fractions. For both the cytosol and membrane fractions, the 2 cAMP receptor proteins represented almost all of the proteins specifically labeled by 8-azido[32P]cAMP and appeared to be the regulatory subunits of cAMP-dependent protein kinases.