[SFP1 controls translation termination in Saccharomyces cerevisiae via regulation of the Sup35p (eRF3) level].

Translation termination in yeast performed by Sup45 (eRF1) and Sup35 (eRF3) proteins is a subject to complicated genetic control. Among the potential candidate genes that participate in regulation of translation termination is SFP1 encoding the global transcription factor Sfp1p. The data obtained earlier in our work indicate that SFP1 deletion causes a weak nonsense suppression mediated by a decrease in Sup35p amount. In this work, we performed a further study of mechanism by which SFP1 regulates translation termination efficiency. To this aim, effects of SFP1 overexpression on manifestation of SUP45 mutations, disturbing termination and causing nonsense suppression, and on Sup35p and Sup45p production were studied. It was shown that SFP1 overexpression causes a specific phenotypic change in mutants and increases the termination efficiency. Notably, the Sup45p amount in strains overexpressing SFP1 is not altered, while sup35p amount increases. Thus, we may state that SFP1 participates in the control of translation termination by means of regulation of Sup35p level.