ATP-citrate lyase phosphorylation in rat adipose tissue.
Previous in vitro studies demonstrated that ATP-citrate lyase is phosphorylated by cyclic AMP-dependent protein kinase at peptide A, containing a phosphoserine residue, and by ATP-citrate lyase kinase at peptide B, containing both phosphoserine and phosphothreonine residues (Ramakrishna, S., Pucci, D. L., and Benjamin, W. B. (1983) J. Biol. Chem. 258, 4950-4956). In the present study, trypsin-digested, radiolabeled ATP-citrate lyase from rat epididymal fat pads was analyzed by high performance liquid chromatography. Phosphorylation occurred at three amino acid residues within two different peptide sequences; one (peptide a) contained phosphoserine and the other (peptide b) contained phosphoserine and phosphothreonine. The retention times and molecular weights were the same for peptides a and A and peptides b and B. Isoproterenol action increased peptide a phosphorylation and, to a lesser extent, peptide b phosphorylation. Insulin action also increased peptide a phosphorylation, but did not increase peptide b phosphorylation.
D001275:ATP Citrate (pro-S)-Lyase / Q000302:isolation & purification / Q000378:metabolism*; D000273:Adipose Tissue / Q000201:enzymology*; D000818:Animals; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D010446:Peptide Fragments / Q000032:analysis; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014357:Trypsin
D010446:Peptide Fragments; D001275:ATP Citrate (pro-S)-Lyase; D011494:Protein Kinases; D014357:Trypsin; D007545:Isoproterenol