Phosphorylation of the regulatory subunit of type II beta cAMP-dependent protein kinase by cyclin B/p34cdc2 kinase impairs its binding to microtubule-associated protein 2

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 90; no. 12; pp. 5418 - 5422
• Main Authors: Keryer, G, Luo, Z, Cavadore, J C, Erlichman, J, Bornens, M
• Format: Journal Article
• Language: English
• Published: Washington, DC National Acad Sciences 15.06.1993; National Academy of Sciences of the United States of America
• Subjects: Adenosine Triphosphate - metabolism; Analytical, structural and metabolic biochemistry; Animals; Binding Sites; Biological and medical sciences; Brain - enzymology; Carrier Proteins - metabolism; Cattle; CDC2 Protein Kinase - isolation & purification; CDC2 Protein Kinase - metabolism; Cyclins - metabolism; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; HeLa Cells; Humans; Isoenzymes - isolation & purification; Isoenzymes - metabolism; Macromolecular Substances; Microtubule-Associated Proteins - isolation & purification; Microtubule-Associated Proteins - metabolism; Peptide Fragments - metabolism; Phosphoproteins - isolation & purification; Phosphoproteins - metabolism; Phosphorylation; Protein Binding; Protein Kinases - isolation & purification; Protein Kinases - metabolism; Recombinant Fusion Proteins - isolation & purification; Recombinant Fusion Proteins - metabolism; Starfish - enzymology; Transferases; Phosphorylation; Regulation(control); Enzyme; Isozyme; Protein kinase; Affinity; Microtubule associated protein; Intracellular; Regulatory subunit; Localization
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.90.12.5418

Subcellular localization of type II cAMP-dependent protein kinase is determined by the interactions of the regulatory subunit (RII) with specific RII-anchoring proteins. By using truncated NH2-terminal RII beta fusion proteins expressed in Escherichia coli and the mitotic protein kinase p34cdc2 isolated from HeLa cells or starfish oocytes, we investigated the in vitro phosphorylation of RII beta by these kinases. The putative site for phosphorylation by the mitotic kinases is Thr-69 in the NH2-terminal domain of RII beta. This phosphorylation site matches the consensus sequence X(T/S)PX(K/R) for p34cdc2 recognition and belongs to a well-conserved sequence found in all RII beta sequences known to date. In contrast to phosphorylation by casein kinase II or the cAMP-dependent protein kinase catalytic subunit, phosphorylation of RII beta by mitotic kinases impaired its interaction with a well-known RII-anchoring protein, the neuronal microtubule-associated protein 2. The potential regulatory significance of the phosphorylation of this site on the interaction with microtubule-associated protein 2 and other RII-anchoring proteins and the physiological relevance of this cyclin B/p34cdc2 kinase-catalyzed modification of RII beta (or phosphorylation by other proline-directed protein kinases) are discussed.