title: Progress through G1 and S in relation to net protein accumulation in human NHIK 3025 cells.
abstract: We have investigated whether human NHIK 3025 cells are dependent upon a net increase in cellular protein content in order to traverse G1 and S. The increase in DNA and protein content was studied by means of two-parameter flow cytometry using populations of cells synchronized by mitotic selection. By adding 1 microM cycloheximide to the medium protein synthesis was partially inhibited, resulting in negligible net accumulation of protein. The cells were able to enter S and progress through S under such conditions. The latter was the case whether the cells had been accumulating protein during G1 or not. The results further indicate that the larger cells enter S earlier and traverse S at a higher rate than the smaller cells. Our conclusion is that net accumulation of protein does not seem to be a prerequisite for traverse through G1 and S, i.e. DNA replication may be dissociated from the general growth of cell mass.
mesh_terms: D002460:Cell Line; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D006801:Humans; D007399:Interphase; D007700:Kinetics; D014176:Protein Biosynthesis
chemical_list: D004247:DNA; D003513:Cycloheximide