title: Flow kinetics of mouse histocompatibility antigens.
abstract: Major histocompatibility antigens of the mouse (H-2 antigens) are found on a variety of different cell types and constitute a class of integral membrane-bound glycoproteins involved in tissue graft rejection and immune surveillance. We used monospecific alloantibodies directed against mouse H-2 antigens and standard pulse-chase technique to investigate the flow kinetics of delivery of newly synthesized membrane constituents to the cell surface. [35S]Methionine was injected intraperitoneally, and, after a chase with unlabeled methionine, livers were excised and fractionated into endoplasmic reticulum, Golgi apparatus, and plasma membrane fractions. Label first appeared in H-2 antigens located within the endoplasmic reticulum. Maximum specific activity observed between 5-7 min after injection of label was followed by a rapid loss of label. H-2 antigens of Golgi apparatus also were labeled early. Peak specific activity observed 15-25 min after injection of label was again followed by rapid loss of label. H-2 antigens of the plasma membrane were labeled last and appeared to accumulate radioactivity with no evidence of rapid turnover. These results provide evidence for a precursor-product relationship between H-2 antigens located within the cell on membranes of endoplasmic reticulum and Golgi apparatus and those on the plasma membrane. Flow of individual membrane-bound glycoproteins from their sites of synthesis and insertion into the membrane of the endoplasmic reticulum to the plasma membrane through the Golgi apparatus is indicated.
mesh_terms: D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D006183:H-2 Antigens; D007700:Kinetics; D008099:Liver / Q000276:immunology*; D051379:Mice; D008970:Molecular Weight; D014176:Protein Biosynthesis; D011506:Proteins / Q000032:analysis; D011863:Radioimmunoassay; D013347:Subcellular Fractions / Q000032:analysis
chemical_list: D006183:H-2 Antigens; D011506:Proteins