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Cyclic AMP‐dependent protein kinase and Ca 2+ ‐calmodulin stimulate the formation of polyphosphoinositjdes in a sarcoplasmic reticulum preparation of rabbit heart
Author(s) -
Enyedi Ágnes,
Faragó Anna,
Sarkadi B.,
Gárdos G.
Publication year - 1984
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(84)80948-5
Subject(s) - phospholamban , endoplasmic reticulum , calmodulin , protein kinase a , protein subunit , phosphatidylinositol , biochemistry , chemistry , kinase , biophysics , biology , enzyme , gene
A rabbit heart membrane fraction enriched in sarcoplasmic reticulum was incubated in a reaction mixture containing [γ‐ 32 P]ATP. The catalytic subunit of cyclic AMP‐dependent protein kinase enhanced the 32 P‐labelling of both phosphatidylinositol‐4‐phosphate and phosphatidylinositol‐4,5‐bisphosphate. Ca 2+ ‐calmodulin also increased the 32 P‐incorporation into both polyphosphoinositides. Upon SDS gel‐electrophoretic analysis of the membrane proteins, phospholamban was found to be concurrently phosphorylated by the exogenous catalytic subunit as well as by an endogenous Ca 2+ ‐calmodulm‐dependent protein kinase.