The Ha-ras protein, p21, is modified by a derivative of mevalonate and methyl-esterified when expressed in the insect/baculovirus system.
Using the insect/baculovirus expression system, we demonstrate the incorporation of [3H]mevalonate and [3H]methyl groups into recombinant c-Ha-ras protein (p21). Unlike the post-translational palmitoylation of p21 expressed in this system, the modification by mevalonate is not removed by hydroxylamine suggesting the absence of a thioester linkage. It is highly likely that the insect expression system recognizes the C-terminal CAAX Motif in p21, incorporates the mevalonate into the recently described polyisoprenylation modification and carboxyl-methylates the protein.
Department of Molecular Sciences, Wellcome Research Laboratories, Beckenham, Kent, UK.
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D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D004952:Esters; D015870:Gene Expression; D066298:In Vitro Techniques; D007304:Insect Viruses; D007313:Insecta; D008798:Mevalonic Acid / Q000378:metabolism*; D008969:Molecular Sequence Data; D015689:Oncogene Protein p21(ras) / Q000378:metabolism*; D011092:Polyethylene Glycols; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000378:metabolism; D012995:Solubility; D013329:Structure-Activity Relationship
D004952:Esters; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D015689:Oncogene Protein p21(ras); D008798:Mevalonic Acid