Skip to main content
The Journal of Neuroscience logoLink to The Journal of Neuroscience
. 1987 Mar 1;7(3):847–853. doi: 10.1523/JNEUROSCI.07-03-00847.1987

Similarities between protein IIIa and protein IIIb, two prominent synaptic vesicle-associated phosphoproteins

MD Browning, CK Huang, P Greengard
PMCID: PMC6569067  PMID: 3104551

Abstract

Protein IIIa (Mr 74,000) and protein IIIb (Mr 55,000) are 2 major phosphoproteins found in mammalian brain. It was previously shown in intact nerve cells that the phosphorylation state of these 2 proteins could be increased by electrical stimulation, by depolarizing agents in the presence of calcium, and by 8-bromo-cAMP. We now report that protein IIIa and protein IIIb possess significant structural homology, as indicated by immunochemical studies using polyclonal and monoclonal antibodies and by peptide-mapping studies. A quantitative radioimmunoassay using immunolabeling in SDS-polyacrylamide gels has been used to study the tissue distribution and regional and subcellular distribution in the brain of the 2 proteins. The 2 proteins were found only in nervous tissue and the adrenal medulla. Subcellular fractionation studies suggested that both proteins are associated with synaptic vesicles.


Articles from The Journal of Neuroscience are provided here courtesy of Society for Neuroscience

RESOURCES