title: The presence of protein kinase activity and acceptors of phosphate groups in nonpolysomal cytoplasmic messenger ribonucleoprotein complexes of embryonic chicken muscle.
abstract: Nonpolysomal cytoplasmic (free) mRNA.protein (mRNP) complexes of embryonic chicken muscle were purified by a combination of oligo(dT)-cellulose chromatography and sucrose density gradient centrifugation. The protein moieties of the purified mRNP complex were analyzed by two-dimensional gel electrophoresis using separation according to charge in the first dimension and molecular weight in the second. Sixteen polypeptides of Mr = 27,000 to 75,000 were present in the mRNP complex. These mRNP polypeptides displayed different electrophoretic migration properties than those of ribosomal proteins. A protein kinase activity was found associated with the mRNP. This enenzyme was able to transfer phosphate group(s) from ATP to at least three acidic mRNP polypeptides of Mr = 27,000, 38,000, and 73,000 and one basic polypeptide of Mr = 75,000. Among these, the Mr = 38,000 acidic polypeptide was the best acceptor of phosphate groups.
mesh_terms: D000818:Animals; D002642:Chick Embryo; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology*; D009698:Nucleoproteins / Q000378:metabolism*; D010766:Phosphorylation; D011132:Polyribosomes; D011494:Protein Kinases / Q000378:metabolism*; D012333:RNA, Messenger / Q000302:isolation & purification / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D009698:Nucleoproteins; D012333:RNA, Messenger; D012261:Ribonucleoproteins; D011494:Protein Kinases