Myristoylation of heparan sulfate proteoglycan and proteins occurs post-translationally in human colon carcinoma cells.
We have recently shown that the heparan sulfate proteoglycan of human colon carcinoma cells is acylated with both myristate and palmitate, two long-chain saturated fatty acids. In this study we show that cycloheximide did not significantly inhibit the incorporation of myristic acid into either proteoglycan or total protein pool. This lack of inhibition occurred under a condition in which protein synthesis was inhibited greater than 90%. Cycloheximide, on the other hand, did not affect the incorporation of [3H]myristic acid into fatty acid nor the intracellular interconversion of myristate to palmitate. Characterization of fatty acyl moiety in the proteoglycan and protein by reverse-phase HPLC revealed that approximately 60% of the covalently bound fatty acids was myristate and the remaining 40% was palmitate. These results indicate that in human colon carcinoma cells myristoylation of heparan sulfate proteoglycan and proteins occurs post-translationally, presumably in the Golgi complex.
Iozzo
R V
RV
Department of Pathology and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107.
Hacobian
N
N
D000215:Acylation; D011508:Chondroitin Sulfate Proteoglycans / Q000235:genetics*; D003110:Colonic Neoplasms; D003513:Cycloheximide / Q000494:pharmacology; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate / Q000235:genetics*; D006801:Humans; D007700:Kinetics; D019814:Myristic Acid; D009227:Myristic Acids / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics*; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism; D011499:Protein Processing, Post-Translational
D011508:Chondroitin Sulfate Proteoglycans; D003513:Cycloheximide; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D019814:Myristic Acid; D009227:Myristic Acids; D009363:Neoplasm Proteins; D019308:Palmitic Acid; D010169:Palmitic Acids