title: Synthesis of plasma membrane-associated and secretory immunoglobulin in diploid lymphocytes.
abstract: The half disappearance time for detectable plasma membrane-associated and cytoplasmic immunoglobulin after treatment of continuously growing diploid lymphocytes with inhibitors of protein and RNA synthesis was studied. Also, the amount of plasma membrane-associated and cytoplasmic immunoglobulin of synchronized cells in the G(1) phase of the cell cycle has been studied. Plasma membrane-associated immunoglobulin has a half disappearance time of 45 min after inhibition of protein synthesis. By contrast, after treatment of cells with actinomycin D for 24 hr, plasma membrane-associated immunoglobulin remains relatively unchanged whereas cytoplasmic immunoglobulin decreased by almost 90%. In the G(1) phase of the cell cycle, plasma membrane-associated immunoglobulin and cytoplasmic immunoglobulin were 70 and 10%, respectively, of that in logarithmically growing cells, and the half disappearance of M-Ig after treatment of cells with puromycin was again 45 min. In toto, these results suggest that perhaps secreted and plasma membrane-associated immunoglobulin may be separately controlled by the cells.
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000276:immunology*; D003593:Cytoplasm / Q000276:immunology*; D004171:Diploidy; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis*; D008214:Lymphocytes / Q000378:metabolism*; D011817:Rabbits
chemical_list: D007136:Immunoglobulins