LOCALIZATION OF RC3 (NEUROGRANIN) IN RAT-BRAIN SUBCELLULAR-FRACTIONS

Previous studies have shown that RC3 (neurogranin) is a postsynaptic,p rotein kinase C (PKC)/calmodulin-binding substrate that accumulates th roughout the perikaryal and dendritic cytoplasm and is often closely a ssociated with the postsynaptic density (PSD) in dendritic spines of n eostriatal neurons. Here Western immunoblotting studies of rat brain s ubcellular fractions confirm that RC3 is predominantly a cytosolic pro tein but is found in lower amounts in membrane-enriched microsomes and synaptosomes. Solubilization of synaptosomes suggests that RC3 may on ly be loosely associated with the PSD.