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Calcium‐ and phospholipid‐dependent phosphorylation of ribulose‐1,5‐bisphosphate carboxylase/oxygenase small subunit by a chloroplast envelope‐bound protein kinase in situ
Author(s) -
Muto Shoshi,
Shimogawara Kousuke
Publication year - 1985
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(85)80085-5
Subject(s) - biochemistry , ribulose 1,5 bisphosphate , protein kinase a , chloroplast membrane , biology , chemistry , phosphorylation , oxygenase , chloroplast , enzyme , thylakoid , gene
Phosphorylation of the ribulose‐1,5‐bisphosphate carboxylase/oxygenase small subunit and other polypeptides by a protein kinase bound to the chloroplast envelope in situ was inhibited by EGTA, but not by calmodulin antagonists. When the envelope membrane was extracted with 90% ( ) cold acetone, the protein kinase activity was completely lost. The activity was restored by adding a lipid fraction extracted from the chloroplast envelope, or phospholipids such as phosphatidylserine and phosphatidylcholine. Treatment of the envelope with phospholipases decreased the protein kinase activity. This was restored by the addition of phospholipids. These results strongly suggest that the envelope‐bound protein kinase is a Ca 2+ ‐and phospholipid‐dependent enzyme.