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Characterization of npl3‐95 as a Prion‐Like Protein Involved in Translation Termination in Saccharomyces cerevisiae
Author(s) -
Bracho Dina Paola,
Correa Maria E.,
Lasalde Clarivel,
González Jose A.,
Estrella Luis A.,
González Carlos I.
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.958.4
Subject(s) - saccharomyces cerevisiae , mutant , translation (biology) , asparagine , protein biosynthesis , biology , rna , eukaryotic translation , polysome , genetics , microbiology and biotechnology , ribosome , biochemistry , chemistry , yeast , messenger rna , gene , amino acid
Npl3 is a yeast protein that participates in various steps of mRNA biogenesis including: transcription, RNA export, processing and translation. Npl3 contains a N‐terminal region with a high glutamine and asparagine content. It also harbors a PXXP domain implicated in protein‐protein interactions. Our previous studies showed that the npl3‐95 allele within the RNA recognition motif 2 of Npl3 affects translation termination accuracy. This mutation causes the formation of high‐molecular weight (HMW) complexes not associated with polysomes. The aim of this project is to study if these novel HMW complexes are prion aggregates and their relationship with translation termination fidelity. To test this, we determined cytoplasmic inheritance of the mutant strain using cytoduction. We examined the sensitivity of the npl3‐ 95 strain and cytoductants to paromomycin. To evaluate the translation termination of cytoductants, the ade2‐1 analysis was also used. Yeast defective in translation termination allowed adenine synthesis and growth in media lacking adenine. Notably, the phenotypes observed in the npl3‐95 strain were “cured” by guanidine hydrochloride treatment and transferred through cytoplasmic inheritance. These results suggest that the mutant form encoded by the npl3‐95 allele acts as a prion‐like protein and further establishes a novel mechanism to regulate translation termination fidelity in yeast.