Informational suppressor alleles of the eEF1A gene, fertility and cell degeneration in Podospora anserina

Abstract

Mutations that increase readthrough at a UGA stop codon (informational suppressor mutations) were created in the gene (AS4) that encodes translation elongation factor eEF1A in the filamentous fungus Podospora amserina. The results strongly suggest that the net charge of the eEF1A protein controls the accuracy of translation. Physiological analysis of the mutant strains shows that some of the alleles dominantly increase life span, while only one drastically modifies fertility. This exceptional allele (AS4-56) causes a wide array of phenotypes, including a new growth cessation phenomenon that is different from Senescence or Crippled Growth, previously known degenerative syndromes that are both controlled by AS4. The data emphasise the fact that eEF1A exerts a complex control over cellular physiology.

Rab-GDI Complex Dissociation Factor Expressed through Translational Frameshifting in Filamentous Ascomycetes

“…The regulatory proteins, whose diminished expression could be responsible for both alterations as hypothesized by Picard-Bennoun, are still unknown. Moreover, altering translation accuracy results in altered lifespan [17,18], through presently unknown mechanism(s) [15,17,19,20]. While sequencing the P. anserina genome, we identified potential candidates regulated by recoding that could explain the importance of maintaining a certain level of translational error [21].…”