Covalent attachment of palmitoleic acid (C16:1 delta 9) to proteins in Saccharomyces cerevisiae. Evidence for a third class of acylated proteins.
Saccharomyces cerevisiae was used as a model system to characterize the covalent attachment of palmitoleic acid to proteins. Chemically synthesized cis-[9,10-3H]hexadecenoic acid (palmitoleic acid) was used to demonstrate the attachment of this lipid species to at least six proteins (m = 122, 58, 45, 41, 31, and 17 kDa). The majority of the labeled proteins are distinct from those labeled with [3H]palmitic acid (16:0). Based on the lability of the bond in the presence of methanolic KOH or hydroxylamine (pH 8), we propose that [3H] palmitoleic acid is attached to proteins via a thioester linkage. The identity of the palmitoleic acid was established by C-18 reverse phase high performance thin layer chromatography and argentation thin layer chromatography analysis after the fatty acid was liberated from the proteins by either transesterification or saponification. Incorporation of [3H]palmitoleic acid into proteins was only slightly inhibited (relative to [3H] myristic acid) by the presence of cycloheximide, indicating that the attachment of [3H]palmitoleic acid occurs post-translationally. This report is the first description of multiprotein acylation by a long chain unsaturated fatty acid.
Casey
W M
WM
Department of Microbiology, North Carolina State University, Raleigh 27695-7615.
Gibson
K J
KJ
Parks
L W
LW
D000215:Acylation; D002250:Carbon Radioisotopes; D002855:Chromatography, Thin Layer; D004591:Electrophoresis, Polyacrylamide Gel; D005229:Fatty Acids, Monounsaturated / Q000138:chemical synthesis / Q000378:metabolism*; D005656:Fungal Proteins / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D014316:Tritium
D002250:Carbon Radioisotopes; D005229:Fatty Acids, Monounsaturated; D005656:Fungal Proteins; D014316:Tritium; C008757:palmitoleic acid