Cloning and Characterization of a Dictyostelium Myosin I Heavy Chain Kinase Activated by Cdc42 and Rac
| Autor: | Amjad Mahasneh, Thomas T. Egelhoff, Sheu Fen Lee, Graham P. Côté |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Myosin light-chain kinase
Molecular Sequence Data Protozoan Proteins Guanosine Cell Cycle Proteins macromolecular substances Biochemistry Substrate Specificity Serine chemistry.chemical_compound GTP-Binding Proteins Myosin Animals Dictyostelium Amino Acid Sequence Cloning Molecular Molecular Biology cdc42 GTP-Binding Protein Saccharomyces cerevisiae Sequence Homology Amino Acid biology Kinase Autophosphorylation Cell Biology biology.organism_classification rac GTP-Binding Proteins Enzyme Activation Isoenzymes chemistry Calcium-Calmodulin-Dependent Protein Kinases Phosphorylation |
| Zdroj: | Journal of Biological Chemistry. 271:27044-27048 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.271.43.27044 |
| Popis: | The motile activities of the small, single-headed class I myosins (myosin I) from the lower eukaryotes Acanthamoeba and Dictyostelium are activated by phosphorylation of a single serine or threonine residue in the head domain of the heavy chain. Recently, we purified a myosin I heavy chain kinase (MIHCK) from Dictyostelium based on its ability to activate the Dictyostelium myosin ID isozyme (Lee, S. -F., and Côté, G. P. (1995) J. Biol. Chem. 270, 11776-11782). The complete sequence of the Dictyostelium MIHCK has now been determined, revealing a protein of 98 kDa that is composed of an amino-terminal domain rich in proline, glutamine, and serine, a putative Cdc42/Rac binding motif, and a carboxyl-terminal kinase catalytic domain. MIHCK shares significant sequence identity with the Saccharomyces cerevisiae Ste20p kinase and the mammalian p21-activated kinase. Gel overlay assays and affinity chromatography experiments showed that MIHCK interacted with GTPgammaS (guanosine 5'-3-O-(thiotriphosphate))-labeled Cdc42 and Rac1 but not RhoA. In the presence of GTPgammaS-Rac1 MIHCK autophosphorylation increased from 1 to 9 mol of phosphate/mol, and the rate of Dictyostelium myosin ID phosphorylation was stimulated 10-fold. MIHCK may therefore provide a direct link between Cdc42/Rac signaling pathways and motile processes driven by myosin I molecules. |
| Databáze: | OpenAIRE |
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