title: Turnover of protein components of the plasma membrane of Saccharomyces cerevisiae.
abstract: The peptide composition of plasma membrane in Saccharomyces cerevisiae cells growing at different temperatures between 18 and 38 degrees C was studied using SDS-polyacrylamide gel electrophoresis. Stability of the proteins, both qualitative and quantitative, was observed at the tested temperatures. Treatment for 2 h with cycloheximide decreased by about 50% the amount of a 80 kDa membrane peptide at 18, 23, 28 and 33 degrees C, with no other apparent effects. At 38 degrees C the 80 kDa peptide was not affected by the presence of the drug. Addition of tunicamycin to cultures at concentrations partially inhibitory to growth caused a large accumulation of the 80 kDa peptide in the plasma membrane, which cycloheximide did not modify. Pulse-chase experiments indicated a low rate of turnover of total plasma membranes in cells growing at 18 and 28 degrees C. In contrast, at 38 degrees C about 50% of the radioactivity in plasma membranes disappeared after a 2 h chase. The 80 kDa protein band was the only one with significant differential decay.
mesh_terms: D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003520:Cyclophosphamide / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D005656:Fungal Proteins / Q000378:metabolism*; D007700:Kinetics; D008565:Membrane Proteins / Q000378:metabolism*; D008970:Molecular Weight; D010455:Peptides / Q000032:analysis; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D013696:Temperature; D014415:Tunicamycin / Q000494:pharmacology
chemical_list: D005656:Fungal Proteins; D008565:Membrane Proteins; D010455:Peptides; D014415:Tunicamycin; D003520:Cyclophosphamide