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Original Research ARTICLE Provisionally accepted The full-text will be published soon. Notify me

Front. Microbiol. | doi: 10.3389/fmicb.2019.02366

Messenger RNAs of yeast virus-like elements contain nontemplated 5' poly(A) leaders, and their expression is independent of eIF4E and Pab1

  • 1Faculty of Science, Charles University, Czechia

We employed virus-like elements (VLEs) pGKL1,2 from Kluyveromyces lactis as a model to investigate the previously neglected transcriptome of the broader group of yeast cytoplasmic linear dsDNA VLEs. We performed 5' and 3' RACE analyses of all pGKL1,2 mRNAs and found them not 3' polyadenylated and containing frequently uncapped 5' poly(A) leaders that are not complementary to VLE genomic DNA. The degree of 5' capping and/or 5' mRNA polyadenylation is specific to each gene and is controlled by the corresponding promoter region. The expression of pGKL1,2 transcripts is independent of eIF4E and Pab1 and is enhanced in lsm1Δ and pab1Δ strains. We suggest a model of primitive pGKL1,2 gene expression regulation in which the degree of 5' mRNA capping and 5' nontemplate polyadenylation, together with the presence of negative regulators such as Pab1 and Lsm1, play important roles. Our data also support a hypothesis of a close relationship between yeast linear VLEs and poxviruses.

Keywords: pGKL, poly(A) leader, poxvirus, eIF4E, Pab1, VLE, virus-like element, linear cytoplasmic plasmid, LSm1, translation, toxin, Pbp1, transcription, mRNA capping, 5' RACE, 3' RACE

Received: 26 Apr 2019; Accepted: 30 Sep 2019.

Copyright: © 2019 Vopálenský, Sýkora, Mašek and Pospíšek. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence:
Dr. Václav Vopálenský, Faculty of Science, Charles University, Prague, 128 43, Prague, Czechia,
Dr. Martin Pospíšek, Faculty of Science, Charles University, Prague, 128 43, Prague, Czechia,