Fatty acylation of polypeptides in the nematode Caenorhabditis elegans

Covalent modification of eucaryotic proteins, involving addition of fatty acyl groups, is a widespread phenomenon. Here we describe the occurrence of this form of covalent modification in the free-living nematode, Caenorhabditis elegans. Following incubation in the presence of either [3H]-myristic acid or [3H]-palmitic acid, specific C. elegans polypeptides became labelled. Chemical analysis revealed that following incubation of C. elegans with [3H]-myristic acid, polypeptides became labelled with myristoyl, palmitoyl or stearoyl moieties; after incubation with [3H]-palmitic acid, palmitoyl or stearoyl moieties were incorporated into polypeptides. Fatty acyl groups were linked to target polypeptides, predominantly through alkali-labile thioester or ester linkages and acid-labile amide linkages. Where myristoylation involved an amide linkage, the modified amino acid was usually glycine. Preliminary immunological evidence indicated that heterotrimeric GTP-binding protein alpha subunit(s) are possible target(s) for acylation in C. elegans.