title: eIF-2 initiation factor activity in Yoshida ascites hepatoma AH 130 cells and in 4-dimethylaminoazobenzene-induced liver tumor tissue during growth.
abstract: Eukaryotic initiation factor 2 (eIF-2) preparations from mid-log and plateau-phase Yoshida ascites hepatoma AH 130 cells, from the liver of Yoshida ascites tumor-bearing rats and from 4-dimethylaminoazobenzene (DAB)-induced liver tumor tissue were assayed for ternary complex formation with 3H-met-tRNAf and GTP on nitrocellulose filters. The eIF-2 factor was extracted from postnuclear homogenate supernatants by high-salt wash and purified by ion exchange chromatography on DEAE-cellulose and phosphocellulose. The results here reported demonstrate changes of 3H-met-tRNAf X eIF-2 X GTP ternary complex formation under the conditions studied. Higher rates of ternary complex formation are present in control rat liver and in DAB-induced liver tumor tissue. The liver of Yoshida ascites tumor-bearing rats and the Yoshida ascites hepatoma cells show reduced rates of ternary complex formation, that are mostly evident at the plateau-phase of the intraperitoneal ascites cell growth. The present observations may be attributable to changes in the growing conditions of plateau-phase ascites cells, with accumulation in Gl phase, affecting the ability of eIF-2 to enter in the sequential assembly of the eukaryotic protein synthesis initiation complex.
mesh_terms: D000818:Animals; D015852:Eukaryotic Initiation Factor-2; D006160:Guanosine Triphosphate / Q000378:metabolism; D008099:Liver / Q000254:growth & development / Q000378:metabolism*; D008114:Liver Neoplasms, Experimental / Q000378:metabolism*; D010442:Peptide Chain Initiation, Translational; D010448:Peptide Initiation Factors / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D012343:RNA, Transfer / Q000378:metabolism; D051381:Rats; D004124:p-Dimethylaminoazobenzene
chemical_list: D015852:Eukaryotic Initiation Factor-2; D010448:Peptide Initiation Factors; D011506:Proteins; D006160:Guanosine Triphosphate; D012343:RNA, Transfer; D004124:p-Dimethylaminoazobenzene