Phosphorylation of partially purified 1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine:acetyl-CoA acetyltransferase from rat spleen.
A new improved method for purification of the enzyme 1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine: acetyl-CoA acetyltransferase (EC 2.3.1.67) from rat spleen is described. The catalytic subunit of cyclic AMP-dependent protein kinase in the presence of MgATP stimulated about 3-fold the activity of this partially purified enzyme activity. When [gamma-32P]ATP was included in the assay mixture, the analysis of phosphoprotein products by SDS/polyacrylamide-gel electrophoresis and autoradiography showed the incorporation of [32P]phosphate into a single protein band of about 30 kDa. Analysis of the phosphorylated amino acids indicated that the phosphate was incorporated into a serine residue. Activation of the acetylation reaction by the protein kinase was reversible. The reversal of the activation was coincident with the loss of the [32P]phosphate incorporated into the 30 kDa protein band, which suggests that the acetyltransferase is regulated by a phosphorylation-dephosphorylation mechanism dependent on cyclic AMP.
Gomez-Cambronero
J
J
Laboratorio de Nefrologia, Instituto de Investigaciones Medicas de la Fundacion Jimenez Diaz, Madrid, Spain.
Mato
J M
JM
Vivanco
F
F
Sanchez-Crespo
M
M
D000123:Acetyltransferases / Q000302:isolation & purification / Q000378:metabolism*; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D051381:Rats; D013154:Spleen / Q000201:enzymology*
D000596:Amino Acids; D000123:Acetyltransferases; C027628:acetyl-CoA-1-alkyl-2-lyso-sn-glycero-3-phosphocholine acetyltransferase; D011494:Protein Kinases