Heterogeneity of protein kinase NII: Multiple subunit-polypeptides

• Published in: FEBS letters Vol. 203; no. 1; pp. 104 - 108
• Main Authors: Qi, Shang-Le, Yukioka, Munehiko, Morisawa, Seiji, Inoue, Akira
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 14.07.1986; Elsevier
• Subjects: Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Cell Nucleus - enzymology; electrophoresis; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Isoelectric Point; Isoenzymes - analysis; liver; Liver - enzymology; Macromolecular Substances; Molecular Weight; Phosphoproteins - analysis; protein kinase; Protein Kinases - analysis; Rats; Transferases; Heterogeneity; Vertebrata; Mammalia; Rat; Protein kinase; Liver; Rodentia; Two dimensional electrophoresis; Subunit
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(86)81446-6

Protein kinase NII has a αα'β 2 subunit structure, and consists of a chromatographically heterogeneous population. By two-dimensional polyacrylamide gel electrophoresis, each subunit was resolved into multiple polypeptides with various pI values: α subunit, 4 spots; α' subunit, 10 spots; and β subunit, 4 spots. NII underwent autophosphorylation on β subunits. Fractions of α and α' polypeptides also occurred as phosphoforms as shown by alkaline phosphatase treatment. In addition, α' subunit had another motif for heterogeneity, which separated α' polypeptides into two groups, and was exemplified by NIIa and NIIb that showed different enzyme kinetics and the nuclear localization. We interpret these results to account for the basis of the functional as well as molecular heterogeneities of protein kinase NII. Protein kinase NII Heterogeneity Subunit polypeptide 2D Polyacrylamide gel electrophoresis Alkaline phosphatase Autophosphorylation