title: Inhibitory diffusible factor IDF45, a G1 phase inhibitor.
abstract: An inhibitory diffusible factor of 45 kDa (IDF45) was isolated from medium conditioned by dense cultures of 3T3 cells. The procedure involved Bio-Gel P150 chromatography and 2 reverse-phase FPLC. After the final step of purification, 60 ng/ml of IDF45 inhibited 50% of alpha-globulin-stimulated DNA synthesis. It was shown that IDF45 acted in the G1 phase of the cell cycle. When added for 8 h in the G1 phase of the cell cycle, it was able to inhibit DNA synthesis in the S phase which followed this G1 phase. Furthermore, IDF45 inhibited the early stimulation of RNA synthesis induced by alpha-globulin.
mesh_terms: D000510:Alpha-Globulins / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D004247:DNA / Q000096:biosynthesis; D006131:Growth Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D007399:Interphase / Q000187:drug effects*; D051379:Mice; D012313:RNA / Q000096:biosynthesis
chemical_list: D000510:Alpha-Globulins; D006131:Growth Inhibitors; D012313:RNA; D004247:DNA