Synthesis and assembly of membrane glycoproteins: presence of leader peptide in nonglycosylated precursor of membrane glycoprotein of vesicular stomatitis virus.
Translation of mRNA encoding vesicular stomatitis virus envelope glycoprotein G by as membrane-free ribosomal extract obtained from HeLa cells yielded a nonglycosylated protein (G1 (Mr 63,000). In the presence of added microsomal membranes, G1 was converted to the glycosylated protein (G2 (Mr 67,000) which is inserted in the membrane vesicles as a transmembrane protein. Labeling with methionine donated by wheat germ initiator tRNA1Met showed that G1 but not G2 contains methionine in the NH2-terminal position. Determination of the NH2-terminal sequence of G1, G2, and G showed that a leader peptide of 16 amino acids is present in G1 but absent from the glycosylated proteins G2 and G. This leader peptide contains at least 62% hydrophobic amino acids and is removed presumably during insertion of G1 into the membrane.
D000595:Amino Acid Sequence; D006023:Glycoproteins / Q000096:biosynthesis*; D008565:Membrane Proteins / Q000096:biosynthesis*; D014176:Protein Biosynthesis; D011498:Protein Precursors / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012995:Solubility; D014721:Vesicular stomatitis Indiana virus / Q000378:metabolism*; D014764:Viral Proteins / Q000096:biosynthesis*
D006023:Glycoproteins; D008565:Membrane Proteins; D011498:Protein Precursors; D012333:RNA, Messenger; D014764:Viral Proteins