Biogenesis of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, an integral glycoprotein of the endoplasmic reticulum.
Using a cell line, C100, that overproduces 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase; EC 1.1.1.34) 100-fold, we have studied the synthesis and insertion of this protein into the endoplasmic reticulum. The enzyme is synthesized on membrane-bound polysomes. It is cotranslationally but not post-translationally inserted into dog pancreatic microsomes. This cotranslational insertion is dependent upon signal recognition particle. HMG-CoA reductase is glycosylated with an oligosaccharide(s) of the "high-mannose" type sensitive to endo-beta-D-N-acetylglucosaminidase H. Partial determination of the NH2-terminal amino acid sequence of the in vitro translation product and the mature polypeptide indicate they are the same and demonstrate there is no cleavage of an NH2-terminal signal sequence.
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D004285:Dogs; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006023:Glycoproteins / Q000096:biosynthesis*; D006903:Hydroxymethylglutaryl CoA Reductases / Q000096:biosynthesis*; D007425:Intracellular Membranes / Q000378:metabolism; D008565:Membrane Proteins / Q000096:biosynthesis*; D010455:Peptides / Q000378:metabolism; D011132:Polyribosomes / Q000378:metabolism; D014176:Protein Biosynthesis; D011498:Protein Precursors / Q000378:metabolism; D021382:Protein Sorting Signals
D006023:Glycoproteins; D008565:Membrane Proteins; D010455:Peptides; D011498:Protein Precursors; D021382:Protein Sorting Signals; D006903:Hydroxymethylglutaryl CoA Reductases