title: Endogenous cyclic AMP-stimulated phosphorylation of a Wolfgram protein component in rabbit central-nervous-system myelin.
abstract: Cyclic AMP-stimulated phosphorylation of membrane proteins in central-nervous-system myelin was investigated, with rabbit brain myelin. Subfractionation of a myelin membrane preparation by sucrose-density-gradient centrifugation produced a rapidly sedimenting population of membrane vesicles containing 5'-nucleotidase and acetylcholinesterase, a light membrane fraction containing myelin basic protein and 2',3'-cyclic nucleotide 3'-phosphodiesterase, and an intermediate membrane fraction containing the highest specific activity of 2',3'-cyclic nucleotide 3'-phosphodiesterase and a small proportion of myelin basic protein. Cyclic AMP stimulation of protein phosphorylation was confined to a protein of Mr 49 700, which co-electrophoresed with the upper component of the Wolfgram protein doublet. Cyclic AMP did not affect the phosphorylation of myelin basic protein. Cyclic AMP-stimulated phosphorylation of this protein followed 2',3'-cyclic nucleotide 3'-phosphodiesterase activity on subcellular fractionation and was correspondingly high in the intermediate or 'myelin-like' fraction on sucrose-density-gradient centrifugation.
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000648:ultrastructure; D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D000242:Cyclic AMP / Q000494:pharmacology*; D066298:In Vitro Techniques; D008854:Microscopy, Electron; D009185:Myelin Proteins / Q000378:metabolism*; D010766:Phosphorylation; D011817:Rabbits; D013268:Stimulation, Chemical; D013347:Subcellular Fractions / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D009185:Myelin Proteins; C028312:Wolfgram proteins; D000242:Cyclic AMP