Lipid phosphorylation in chloroplast envelopes - Evidence for galactolipidCTP-dependent kinase activities

Citation
Mo. Muller et al., Lipid phosphorylation in chloroplast envelopes - Evidence for galactolipidCTP-dependent kinase activities, J BIOL CHEM, 275(26), 2000, pp. 19475-19481
Citations number
46
Categorie Soggetti
Biochemistry & Biophysics
Journal title
JOURNAL OF BIOLOGICAL CHEMISTRY
ISSN journal
00219258 → ACNP
Volume
275
Issue
26
Year of publication
2000
Pages
19475 - 19481
Database
ISI
SICI code
0021-9258(20000630)275:26<19475:LPICE->2.0.ZU;2-K
Abstract
Lipid phosphorylation takes place within the chloroplast envelope. In addit ion to phosphatidic acid, phosphatidylinositol phosphate, and their corresp onding lyse-derivatives, we found that two novel lipids underwent phosphory lation in envelopes, particularly in the presence of carrier-free [gamma-P- 32]ATP, These two lipids incorporated radioactive phosphate in chloroplasts in the presence of [gamma-P-32]ATP or [P-32]P-i and light. Interestingly, these two lipids were preferentially phosphorylated in envelope membranes i n the presence [gamma-P-32]CTP, as the phosphoryl donor, or [gamma-P-32]ATP , when supplemented with CDP and nucleoside diphosphate kinase II. The lipi d kinase activity involved in this reaction was specifically inhibited in t he presence of cytosine 5'-O-(thiotriphosphate) (CTP gamma S) and sensitive to CTP chase, thereby showing that both lipids are phosphorylated by an en velope CTP-dependent lipid kinase. The lipids were identified as phosphoryl ated galactolipids by using an acid hydrolysis procedure that generated gal actose B-phosphate, CTP gamma S did not affect the import of the small ribu lose-bisphosphate carboxylase/oxygenase subunit into chloroplasts, the poss ible physiological role of this novel CTP-dependent galactolipid kinase act ivity in the chloroplast envelope is discussed.