Acanthamoeba myosin I heavy chain kinase is activated by phosphatidylserine-enhanced phosphorylation
| Autor: | T J Lynch, Edward D. Korn, Hanna Brzeska |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
inorganic chemicals
Myosin light-chain kinase biology Cyclin-dependent kinase 2 Autophosphorylation macromolecular substances Cell Biology Mitogen-activated protein kinase kinase environment and public health Biochemistry MAP2K7 Cell biology enzymes and coenzymes (carbohydrates) biology.protein bacteria Cyclin-dependent kinase 9 Molecular Biology Rho-associated protein kinase MAPK14 |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 0021-9258 |
| DOI: | 10.1016/s0021-9258(19)39630-9 |
| Popis: | The actin-activated Mg2(+)-ATPase activities of myosins I from Acanthamoeba castellanii are fully expressed only when a single amino acid on their heavy chain is phosphorylated by myosin I heavy chain kinase. Here we show that kinase isolated by a procedure designed to minimize its phosphorylation during purification can incorporate up to 7.5 mol of phosphate/mol of enzyme when incubated with ATP, possibly by autophosphorylation. The rate of phosphorylation is enhanced about 20-fold by phosphatidylserine but is unaffected by calcium ions. Phosphorylation increases the rate at which the kinase phosphorylates the regulatory site of myosin I by about 50-fold. These results suggest that (auto?)phosphorylation may regulate the activity of myosin I heavy chain kinase in vivo. The stimulation of kinase phosphorylation by phosphatidylserine (other phospholipids have not yet been tested) is of particular interest because myosin I has been shown to be tightly associated with membranes, especially the plasma membrane. |
| Databáze: | OpenAIRE |
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