Transcriptomic analysis of the effect of cytoplasmic Rat1 (cRat1)

ABSTRACT: The main decay pathway of yeast mRNAs in the cytoplasm uses the 5’-3’ exonuclease Xrn1. This protein shuttles from the cytoplasm to the nucleus, where it has a role as transcription factor. We have recently demonstrated that importing depends on two nuclear localization sequences (NLS 1 & NLS2) and that exporting depends on its binding (presumably co-transcriptional) to mRNAs. It is also known that Xrn1 is able to degrade decapped mRNAs that are still being translated by ribosomes. In this work, we analyze the pleiotropic functions of Xrn1 by comparing the phenotypes of yeast strains lacking Xrn1 or its capacity to be imported into the nucleus with those of the substitution of Xrn1 by a cytoplasmic version of the paralogous 5’-3’ exonuclease Rat1 (cRat1). We find that most of the global phenotypes of an xrn1 mutant are partially complemented by cRat1 indicating that this 5’-3’ exonuclease has a similar enzymatic capacity as Xrn1 and that the lack of a cytoplasmic 5’-3’-exoribonuclease is the cause of the physiological defects of an xrn1 mutant. The capacity of cRat1 to perform co-translational decay is, however, very limited. The comparison with the strain carrying Xrn1 with non-functional NLSs (Xrn1ΔNLS1/2) shows that it is slightly deficient in 5’→3’-co-translational decay but much more efficient than cRat1. In both strains, cRat1 and Xrn1ΔNLS1/2, the lack of nuclear Xrn1 has a very minor influence on cell growth experiment in wild type and xrn1 mutant strains.

ORGANISM(S): Saccharomyces cerevisiae

PROVIDER: GSE198240 | GEO | 2024/06/01

REPOSITORIES: GEO