title: Distribution of endogenously phosphorylated proteins in subcellular fractions of rat cerebral cortex.
abstract: The cerebral cortex from adult rats was separated into several subcellular fractions by using established methods of differential and sucrose density gradient centrifugation. Aliquots from each fraction were incubated with γ-(32)P-ATP, in the presence and absence of adenosine 3',5'-monophosphate (cyclic AMP), and its protein constituents were separated by means of SDS-slab gel electrophoresis. Fractions containing nuclei, synaptosomes, myelin, microsomes, and soluble proteins each showed a characteristic pattern of protein staining and of endogenously phosphorylated proteins detected by autoradiography of the gels. Cyclic AMP-stimulated phosphorylation of proteins with MW 78K and 84K can serve as markers for membranes of synaptic origin, while cyclic AMP-independent phosphorylation of low-molecular-weight proteins (15K-20K) is characteristic of myelin. The finding of different phosphoproteins in various subcellular fractions may be related to the diversity of cellular functions known to be regulated by phosphorylative activity.
authors.affiliation: Biochemistry Laboratory Missouri Institute of Psychiatry School of Medicine, University of Missouri, Columbia, 5400 Arsenal Street, 63139, St. Louis, Missouri.
authors.forename: Y H
authors.initials: YH
authors.lastname: Ehrlich
authors.forename: L G
authors.initials: LG
authors.lastname: Davis
authors.forename: T
authors.initials: T
authors.lastname: Gilfoil
authors.forename: E G
authors.initials: EG
authors.lastname: Brunngraber