Phosphorylation of protein tyrosine by human erythrocyte casein kinase A.
Human erythrocyte casein kinase A, previously identified as a seryl, threonyl kinase, was found also to catalyze the phosphorylation of protein tyrosine. Phosphorylation of tyrosyl residues was detected in angiotensin-II and in several tyrosine containing synthetic peptides. In addition, phosphorylation on tyrosyl residues was also observed in alkylated bovine serum albumin and in band 3 and ankyrin purified from human erythrocyte membranes. The identification of phosphotyrosine was conducted using two-dimensional thin layer electrophoresis at pH 1.9 and 3.5 after acid hydrolysis of the phosphoproteins. It should be noted, however, that the major phosphorylation sites in band 3 and ankyrin catalyzed by casein kinase A were seryl and threonyl residues.
D000804:Angiotensin II / Q000378:metabolism; D017487:Ankyrins; D047388:Casein Kinases; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D013912:Threonine / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism*
D017487:Ankyrins; D007527:Isoenzymes; D008565:Membrane Proteins; D010455:Peptides; D000804:Angiotensin II; D013912:Threonine; D014443:Tyrosine; D012694:Serine; D011494:Protein Kinases; D047388:Casein Kinases