Protein kinases A and C phosphorylate purified Ca2+-ATPase from rat cortex, cerebellum and hippocampus.
Biochim Biophys Acta
; 1448(1): 99-108, 1998 Nov 19.
Article
in En
| MEDLINE
| ID: mdl-9824678
ABSTRACT
The plasma membrane Ca2+-ATPase (PMCA), the enzyme responsible for the maintenance of intracellular calcium homeostasis, is regulated by several independent mechanisms. In this paper we report that the protein kinases A and C differentially activate the Ca2+-ATPase purified from synaptosomal membranes of rat cortex, cerebellum and hippocampus. The effect of protein kinases was more pronounced for the cortical enzyme, whereas cerebellar and hippocampal Ca2+-ATPases were activated to a lesser degree. The preparation of Ca2+-ATPase contained the phosphoamino acids, i.e., P-Ser and P-Thr, indicating that the enzyme was purified in phosphorylated state. The phosphorylation of Ca2+-ATPase by PKA and PKC increased the amount of phosphoamino acids, but in a region-dependent manner. Using the specific antibodies against N-terminal portion of four main PMCA isoforms we have characterized the isoforms composition of Ca2+-ATPase purified from the nervous endings of examined brain areas. Our results indicate that the activity of calcium pump is related to its phosphorylated state, and that the phosphorylation is region-dependent. Moreover, the differences observed could be related to the composition of PMCA isoforms in the different brain areas. Phosphorylation of the plasma membrane Ca2+-ATPase appears to be a mechanism to control its activity. The results support also the possible involvement of PKA and PKC.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Brain
/
Protein Kinase C
/
Cell Membrane
/
Calcium-Transporting ATPases
/
Cyclic AMP-Dependent Protein Kinases
Limits:
Animals
Language:
En
Journal:
Biochim Biophys Acta
Year:
1998
Document type:
Article
Affiliation country:
Poland