title: Cell-free synthesis and co-translational processing of the human asialoglycoprotein receptor.
abstract: The human asialoglycoprotein receptor is a 46-kDa membrane glycoprotein. It is initially synthesized as a 40-kDa precursor species possessing two N-linked high-mannose oligosaccharides which is subsequently converted to the 46-kDa mature product upon modification of its oligosaccharides of the complex form [Schwartz, A. L. & Rup, D. (1983) J. Biol. Chem. 258, 11 249-11 255]. To investigate further the biosynthesis of the human asialoglycoprotein receptor, we have utilized a cell-free wheat germ translation system supplemented with dog pancreatic microsomal membranes and programmed with HepG2 and human liver RNA. The primary translation product of the human receptor is a single 34-kDa species and this species is expressed throughout human fetal and adult development. The primary translation product possesses no cleavable signal peptide and is cotranslationally glycosylated to form the 40-kDa precursor species. In addition, the human asialoglycoprotein receptor is co-translationally inserted into microsomal membranes such that a 4-kDa cytoplasmic tail is susceptible to trypsin digestion.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D037263:Asialoglycoprotein Receptor; D002474:Cell-Free System; D004285:Dogs; D006801:Humans; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism; D008113:Liver Neoplasms / Q000378:metabolism; D008861:Microsomes / Q000378:metabolism; D014176:Protein Biosynthesis; D011971:Receptors, Immunologic / Q000032:analysis / Q000096:biosynthesis*; D014357:Trypsin / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D037263:Asialoglycoprotein Receptor; D011971:Receptors, Immunologic; D014357:Trypsin