TY - JOUR

T1 - Nonsense mutations in the yeast SUP35 gene affect the [PSI+] prion propagation

AU - Trubitsina, Nina P.

AU - Zemlyanko, Olga M.

AU - Bondarev, Stanislav A.

AU - Zhouravleva, Galina A.

N1 - Funding Information: Funding: This work was supported by grants from Russian Science Foundation [grant 18‐14‐00050] (plasmid construction, fluorescence microscopy, mutation analysis in haploids) and Russian Foundation for Basic Research [grant 17‐54‐150002] (individual mutation analysis in diploids). Technical help was provided by Resource Center “Development of Molecular and Cell Technologies” of St. Petersburg State University. Authors declare no conflict of interest. Publisher Copyright: © 2020 by the authors. Licensee MDPI, Basel, Switzerland. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/3

Y1 - 2020/3

N2 - The essential SUP35 gene encodes yeast translation termination factor eRF3. Previously, we isolated nonsense mutations sup35-n and proposed that the viability of such mutants can be explained by readthrough of the premature stop codon. Such mutations, as well as the prion [PSI+], can appear in natural yeast populations, and their combinations may have different effects on the cells. Here, we analyze the effects of the compatibility of sup35-n mutations with the [PSI+] prion in haploid and diploid cells. We demonstrated that sup35-n mutations are incompatible with the [PSI+] prion, leading to lethality of sup35-n [PSI+] haploid cells. In diploid cells the compatibility of [PSI+] with sup35-n depends on how the corresponding diploid was obtained. Nonsense mutations sup35-21, sup35-74, and sup35-218 are compatible with the [PSI+] prion in diploid strains, but affect [PSI+] properties and lead to the formation of new prion variant. The only mutation that could replace the SUP35 wild-type allele in both haploid and diploid [PSI+] strains, sup35-240, led to the prion loss. Possibly, short Sup351–55 protein, produced from the sup35-240 allele, is included in Sup35 aggregates and destabilize them. Alternatively, single molecules of Sup351–55 can stick to aggregate ends, and thus interrupt the fibril growth. Thus, we can conclude that sup35-240 mutation prevents [PSI+] propagation and can be considered as a new pnm mutation.

AB - The essential SUP35 gene encodes yeast translation termination factor eRF3. Previously, we isolated nonsense mutations sup35-n and proposed that the viability of such mutants can be explained by readthrough of the premature stop codon. Such mutations, as well as the prion [PSI+], can appear in natural yeast populations, and their combinations may have different effects on the cells. Here, we analyze the effects of the compatibility of sup35-n mutations with the [PSI+] prion in haploid and diploid cells. We demonstrated that sup35-n mutations are incompatible with the [PSI+] prion, leading to lethality of sup35-n [PSI+] haploid cells. In diploid cells the compatibility of [PSI+] with sup35-n depends on how the corresponding diploid was obtained. Nonsense mutations sup35-21, sup35-74, and sup35-218 are compatible with the [PSI+] prion in diploid strains, but affect [PSI+] properties and lead to the formation of new prion variant. The only mutation that could replace the SUP35 wild-type allele in both haploid and diploid [PSI+] strains, sup35-240, led to the prion loss. Possibly, short Sup351–55 protein, produced from the sup35-240 allele, is included in Sup35 aggregates and destabilize them. Alternatively, single molecules of Sup351–55 can stick to aggregate ends, and thus interrupt the fibril growth. Thus, we can conclude that sup35-240 mutation prevents [PSI+] propagation and can be considered as a new pnm mutation.

KW - Nonsense mutations

KW - Prion

KW - S.cerevisiae

KW - Sup35

KW - Translation termination

KW - Yeast

KW - [PSI]

KW - DETERMINANT

KW - [PSI+]

KW - translation termination

KW - SACCHAROMYCES-CEREVISIAE

KW - yeast

KW - OVEREXPRESSION

KW - S

KW - PROTEIN EXTRACTION

KW - SUP45

KW - NON-MENDELIAN FACTOR

KW - PSI(+)

KW - cerevisiae

KW - prion

KW - nonsense mutations

KW - DEPENDENT LETHALITY

KW - EXPRESSION

KW - TRANSLATION TERMINATION

UR - http://www.scopus.com/inward/record.url?scp=85080881356&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/f2c454ef-9cf8-341a-a1c1-11630233c587/

U2 - 10.3390/ijms21051648

DO - 10.3390/ijms21051648

M3 - Article

C2 - 32121268

AN - SCOPUS:85080881356

VL - 21

JO - International Journal of Molecular Sciences

JF - International Journal of Molecular Sciences

SN - 1422-0067

IS - 5

M1 - 1648

ER -