title: Rapid in Vivo Acylation of Acyl Carrier Protein with Exogenous Fatty Acids in Spirodela oligorrhiza.
abstract: Posttranslational acylation of several chloroplast proteins with palmitic acid was recently demonstrated in Spirodela oligorrhiza (AK Mattoo, M Edelman [1987] Proc Natl Acad Sci USA 84: 1497-1501). We have now identified an in vivo acylated, soluble protein having an apparent M(r) of 10 kilodaltons on sodium dodecyl sulfate-polyacrylamide gel electrophoresis as an acylated form of acyl carrier protein (ACP). This 10-kilodalton protein is present in low abundance, and its acylation is light-stimulated. Turnover of the acyl moiety but not the apo-protein is rapid in the light. The acylated 10-kilodalton protein coelectrophoreses with in vitro synthesized palmitoyl-acyl carrier protein and is immunoprecipitated from soluble extracts with an antibody raised against spinach ACP. Cerulenin, an inhibitor of beta-ketoacyl-ACP synthetase, inhibited in vivo acylation of Spirodela ACP. Cell-free extracts of Spirodela plants were able to catalyze the transfer of palmitate from palmitoyl-CoA to ACP, suggesting the existence in higher plants of a pathway for acylation of ACP that involves transacylation from acyl-CoA.
authors: Plant Hormone Laboratory, U.S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, Maryland 20705.
authors: A K
authors: AK
authors: Mattoo
authors: F E
authors: FE
authors: Callahan
authors: R A
authors: RA
authors: Mehta
authors: J B
authors: JB
authors: Ohlrogge