Identification of membrane-bound calcium, calmodulin-dependent protein kinase II in canine heart
| Autor: | Martha Bass, Mary Frances Jett, Charles M. Schworer, Thomas R. Soderling |
|---|---|
| Rok vydání: | 1987 |
| Předmět: |
Myosin light-chain kinase
Biophysics P70-S6 Kinase 1 Calcium-Transporting ATPases macromolecular substances Mitogen-activated protein kinase kinase Biology Biochemistry MAP2K7 Dogs Ca2+/calmodulin-dependent protein kinase Animals Phosphorylation Molecular Biology MAP kinase kinase kinase Myocardium Calcium-Binding Proteins Membrane Proteins Phospholamban Molecular Weight Kinetics Sarcoplasmic Reticulum Cyclin-dependent kinase 9 Ca(2+) Mg(2+)-ATPase Protein Kinases |
| Zdroj: | Archives of Biochemistry and Biophysics. 255:354-360 |
| ISSN: | 0003-9861 |
| DOI: | 10.1016/0003-9861(87)90403-6 |
| Popis: | Phospholamban, the putative regulatory proteolipid of the Ca2/Mg2+ ATPase in cardiac sarcoplasmic reticulum, was selectively phosphorylated by a Ca2+/calmodulin (CaM)-dependent protein kinase associated with a cardiac membrane preparation. This kinase also catalyzed the phosphorylation of two exogenous proteins known to be phosphorylated by the multifunctional Ca2+/CaM-dependent protein kinase II Ca2+/CaM-kinase II), i.e., smooth muscle myosin light chains and glycogen synthase a. The latter protein was phosphorylated at sites previously shown to be phosphorylated by the purified multifunctional Ca2+/CaM-kinase II from liver and brain. The membrane-bound kinase did not phosphorylate phosphorylase b or cardiac myosin light chains, although these proteins were phosphorylated by appropriate, specific calmodulin-dependent protein kinases added exogenously. In addition to phospholamban, several other membrane-associated proteins were phosphorylated in a calmodulin-dependent manner. The principal one exhibited a Mr of approximately 56,000, a value similar to that of the major protein (57,000) in a partially purified preparation of Ca2+/CaM-kinase II from the soluble fraction of canine heart that was autophosphorylated in a calmodulin-dependent manner. These data indicate that the membrane-bound, calmodulin-dependent protein kinase that phosphorylates phospholamban in cardiac membranes is not a specific calmodulin-dependent kinase, but resembles the multifunctional Ca2+/CaM-kinase II. Our data indicate that this kinase may be present in both the particulate and soluble fractions of canine heart. |
| Databáze: | OpenAIRE |
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