FATTY ACYLATION OF POLYPEPTIDES IN THE NEMATODE CAENORHABDITIS-ELEGANS

Covalent modification of eucaryotic proteins, involving addition of fa tty acyl groups, is a widespread phenomenon. Here we describe the occu rrence of this form of covalent modification in the free-living nemato de, Caenorhabditis elegans. Following incubation in the presence of ei ther [H-3]-myristic acid or [H-3]-palmitic acid, specific C. elegans p olypeptides became labelled. Chemical analysis revealed that following incubation of C. elegans with [H-3]-myristic acid, polypeptides becam e labelled with myristoyl, palmitoyl or stearoyl moieties; after incub ation with [H-3]-palmitic acid, palmitoyl or stearoyl moieties were in corporated into polypeptides. Fatty acyl groups were linked to target polypeptides, predominantly through alkali-labile thioester or ester l inkages and acid-labile amide linkages. Where myristoylation involved an amide linkage, the modified amino acid was usually glycine. Prelimi nary immunological evidence indicated that heterotrimeric GTP-binding protein alpha subunit(s) are possible target(s) for acylation in C. el egans. (C) 1998 Elsevier Science B.V.