Dependence of ATP-citrate lyase kinase activity on the phosphorylation of ATP-citrate lyase by cyclic AMP-dependent protein kinase.
ATP-citrate lyase from rat liver and adipose tissue is phosphorylated by either ATP-citrate lyase kinase or catalytic subunit of cyclic AMP-dependent protein kinase to 0.5-0.6 mol/subunit. We previously demonstrated that the site phosphorylated by ATP-citrate lyase kinase (peptide B) is different from that phosphorylated by catalytic subunit of cyclic AMP-dependent protein kinase (peptide A) (Ramakrishna, S., Pucci, D. L., and Benjamin, W.B. (1981) J. Biol. Chem. 256, 10213-10216). ATP-citrate lyase phosphorylation by both protein kinases added simultaneously was increased synergistically. When ATP-citrate lyase was first phosphorylated by catalytic subunit of cyclic AMP-dependent protein kinase, the net phosphorylation of the fragments subsequently phosphorylated by lyase kinase increased about 6-fold. However, when ATP-citrate lyase was first phosphorylated by lyase kinase, there was no effect on the subsequent phosphorylation of the enzyme by cyclic AMP-dependent protein kinase. Alkaline phosphatase-dephosphorylated ATP-citrate lyase was phosphorylated by catalytic subunit of cyclic AMP-dependent protein kinase to 0.9-1.0 mol/subunit. However, dephospho-ATP-citrate lyase was not phosphorylated by lyase kinase. The addition of both protein kinases simultaneously phosphorylated ATP-citrate lyase up to 2 mol/subunit. Phosphorylation of dephospho-ATP-citrate lyase first by catalytic subunit of cyclic AMP-dependent protein kinase and ATP enabled the lyase to be phosphorylated by lyase kinase. Peptide mapping and phosphoamino acid analysis of dephospho-ATP-citrate lyase phosphorylated by catalytic subunit of cyclic AMP-dependent protein kinase and/or lyase kinase conclusively showed that phosphorylation of ATP-citrate lyase by ATP-citrate lyase kinase was completely dependent on peptide A phosphorylation by cyclic AMP-dependent protein kinase. Furthermore, increased phosphorylation when both protein kinases were added simultaneously was due to increased phosphorylation at peptide B.
D001275:ATP Citrate (pro-S)-Lyase / Q000378:metabolism*; D000273:Adipose Tissue / Q000201:enzymology; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D000242:Cyclic AMP / Q000378:metabolism*; D008099:Liver / Q000201:enzymology; D010446:Peptide Fragments / Q000032:analysis; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D014357:Trypsin / Q000378:metabolism
D010446:Peptide Fragments; D000242:Cyclic AMP; D001275:ATP Citrate (pro-S)-Lyase; D011494:Protein Kinases; C032202:ATP-citrate lyase kinase; D014357:Trypsin