Open Access3′ poly(A) is dispensable for translation
Author(s) -
Anjanette M. Searfoss,
Reed B. Wickner
Publication year - 2000
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.97.16.9133
Subject(s) - messenger rna , translation (biology) , rna , p bodies , rna silencing , biology , rna helicase a , microbiology and biotechnology , helicase , mutant , protein biosynthesis , genetics , gene , rna interference
In wild-type cells, the 3′ poly(A) structure is necessary for translation of mRNA and for mRNA stability. Thesuperkiller 2 (ski2), ski3, ski6, ski7 , andski8 mutations enhance the expression of the poly(A)− mRNAs of yeast RNA viruses. Ski2p is a DEVH-box RNA helicase and Slh1p resembles Ski2p. Both repress L-A double-stranded RNA (dsRNA) virus copy number, further suggesting that their functions may overlap. We find thatslh1 Δski2 Δ double mutants are healthy (in the absence of viruses) and show normal rates of turnover of several cellular mRNAs. Theslh1 Δski2 Δ strains translate electroporated nonpoly(A) mRNA with the same kinetics as polyA+ mRNA. Thus, the translation apparatus is inherently capable of efficiently using nonpoly(A) mRNA even in the presence of normal amounts of competing poly(A)+ mRNA, but is normally prevented from doing so by the combined action of the nonessential proteins Ski2p and Slh1p.