Control of macromolecular synthesis in proliferating and resting syrian hamster cells in monolayer culture. III. Electrophoretic patterns of newly synthesized proteins in synchronized proliferating cells and resting cells

Abstract

Electrophoretic patterns of newly synthesized proteins have been compared for hamster embryo fibroblasts in asynchronous cultures, mitotically synchronized cultures, and stationaq phase cultures. Only proteins with molecular weight between 30,000 and 150,000, comprising 60-70 7i of the total cell proteins and excluding histones and collagen were included in the comparison. Although no significant differences could be detected between such patterns for cells at different stages of the cell cycle, significant differences were detectcd between patterns for cells i n stationary phase and for proliferating asynchronous or synchronous cells in any stage of the cell cycle. These differences amounted to at least 5%) of the newly synthesized cellular proteins. Much larger differences were detected between patterns €rom a nuclear fraction of proliferating and resting cells. These results indicate that normal cells in stationary phase are arrested in a state distinct from any phase of the normal cell cycle and may provide a biochemical marker for resting cells.

Protein Synthesis during Photocontrolled Progression of the Cell Cycle in Single‐celled Protonemata of the Fern Adiantum Capillus‐veneris

“…On activation of small lymphocytes, the rate of protein synthesis was accelerated immediately after the stimulation and increased 20-fold over the base line determined before stimulation of DNA synthesis (1). Similar results were reported by many investigators (2)(3)(4)(5)8). But in fern protonemata (Figs.…”

“…BECKER & $TANNERS (8) in studies by one-dimensional gel electro-phoresis, observed a significant difference in the electrophoretic patterns of labelled proteins for cultured Syrian hamster cells in the stationary phase arresed in G , and the proliferating phase, but no significant difference at any stage of the cell cycle in proliferating cells. Similar results have also been obtained in Chinese hamster ovary cells (10) and 3T3 mouse fibroblast cells (9,22).…”

The regulation of DNA synthesis in quiescent lymphocytes by cytoplasmic inhibitors.

“…These results rule out the possibility that the observed inhibition of DNA synthesis was due to small molecular weight substances such, as cyclic nucleotides or prostaglandins or to the competitive inhibition of [3H]TTP incorporation by nonradioactive TTP. Although a number of studies have suggested that quiescent cells contain protein species that are absent in their proliferating counterparts (23)(24)(25)(26), it is presently unclear whether the inhibitory protein described here is unique to resting lymphocytes. It is also unknown whether this protein is continuously synthesized by resting cells or if it represents a stable cellular constituent.…”

Synthesis of 'decidualization-associated protein' in tissues of the rat uterus and placenta during pregnancy

“…Electrophoresis was carried out as previously described (Bell et al, 1977) except that samples containing 100 pg protein were applied to 5% (w/v) acrylamide separating gels. Sodium dodecyl sulphate polyacrylamide gel electrophoresis was carried out as described by Becker & Stanners (1972). Measurement of radioactivity.…”