title: Interrelationships between protein kinases and spectrin phosphorylation in human erythrocytes.
abstract: Casein kinase and histone kinase(s) are solubilized from human erythrocyte membranes by buffered ionic solutions (0.1 mM EDTA and subsequent 0.8 M NaCl, pH 8) containing 0.2% Triton X-100. Casein kinase is separated from histone kinase(s) by submitting the crude extracts directly to chromatography on a phosphocellulose column, eluted with a continuous linear gradient of potassium phosphate buffer, pH 7.0, containing 0.2% Triton X-100. Under these conditions, the membrane-bound casein kinase activity is almost completely recovered into a quite stable preparation, free of histone kinase activity. In contrast, it undergoes a dramatic loss of activity when the extraction and the subsequent phosphocellulose chromatography are carried out with buffers which do not contain Triton X-100. Isolated spectrin, the most abundant membrane protein, is phosphorylated, in the presence of [gamma-32P]ATP, only by casein kinase while histone kinase is ineffective. Only the smaller subunit (band II) of isolated spectrin (and not the larger one (band I) is involved in such a phosphorylation process, as in the endogenous phosphorylation occurring in intact erythrocytes.
mesh_terms: D047388:Casein Kinases; D004910:Erythrocyte Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D010766:Phosphorylation; D006656:Protamine Kinase / Q000097:blood; D011494:Protein Kinases / Q000097:blood* / Q000302:isolation & purification; D013049:Spectrin / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D008565:Membrane Proteins; D013049:Spectrin; D011494:Protein Kinases; D047388:Casein Kinases; D006656:Protamine Kinase