title: The fission yeast MTREC and EJC orthologs ensure the maturation of meiotic transcripts during meiosis.
abstract: Meiosis is a highly regulated process by which genetic information is transmitted through sexual reproduction. It encompasses unique mechanisms that do not occur in vegetative cells, producing a distinct, well-regulated meiotic transcriptome. During vegetative growth, many meiotic genes are constitutively transcribed, but most of the resulting mRNAs are rapidly eliminated by the Mmi1-MTREC (Mtl1-Red1 core) complex. While Mmi1-MTREC targets premature meiotic RNAs for degradation by the nuclear 3'-5' exoribonuclease exosome during mitotic growth, its role in meiotic gene expression during meiosis is not known. Here, we report that Red5, an essential MTREC component, interacts with pFal1, an ortholog of eukaryotic translation initiation factor eIF4aIII in the fission yeast Schizosaccharomyces pombe In mammals, together with MAGO (Mnh1), Rnps1, and Y14, elF4AIII (pFal1) forms the core of the exon junction complex (EJC), which is essential for transcriptional surveillance and localization of mature mRNAs. In fission yeast, two EJC orthologs, pFal1 and Mnh1, are functionally connected with MTREC, specifically in the process of meiotic gene expression during meiosis. Although pFal1 interacts with Mnh1, Y14, and Rnps1, its association with Mnh1 is not disrupted upon loss of Y14 or Rnps1. Mutations of Red1, Red5, pFal1, or Mnh1 produce severe meiotic defects; the abundance of meiotic transcripts during meiosis decreases; and mRNA maturation processes such as splicing are impaired. Since studying meiosis in mammalian germline cells is difficult, our findings in fission yeast may help to define the general mechanisms involved in accurate meiotic gene expression in higher eukaryotes.
authors.affiliation: Department of Biology and Center for Molecular Communication and Signaling, Wake Forest University, Winston-Salem, North Carolina 27106, USA.
authors.forename: Bahjat Fadi
authors.initials: BF
authors.lastname: Marayati
authors.affiliation: Program of Human Genetics, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA.
authors.forename: Victoria
authors.initials: V
authors.lastname: Hoskins
authors.affiliation: Department of Biology and Center for Molecular Communication and Signaling, Wake Forest University, Winston-Salem, North Carolina 27106, USA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Boger
authors.affiliation: Department of Biology and Center for Molecular Communication and Signaling, Wake Forest University, Winston-Salem, North Carolina 27106, USA.
authors.forename: James F
authors.initials: JF
authors.lastname: Tucker
authors.affiliation: Department of Biology and Center for Molecular Communication and Signaling, Wake Forest University, Winston-Salem, North Carolina 27106, USA.
authors.forename: Emily S
authors.initials: ES
authors.lastname: Fishman
authors.affiliation: Department of Biology and Center for Molecular Communication and Signaling, Wake Forest University, Winston-Salem, North Carolina 27106, USA.
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Bray
authors.affiliation: Department of Biology and Center for Molecular Communication and Signaling, Wake Forest University, Winston-Salem, North Carolina 27106, USA.
authors.forename: Ke
authors.initials: K
authors.lastname: Zhang
mesh_terms: D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000378:metabolism; D005091:Exons; D063326:Exosome Multienzyme Ribonuclease Complex / Q000235:genetics / Q000378:metabolism; D055354:Exosomes / Q000235:genetics / Q000378:metabolism*; D007438:Introns; D008540:Meiosis; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D012568:Schizosaccharomyces / Q000235:genetics* / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism; D039221:mRNA Cleavage and Polyadenylation Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; C512176:Mmi1 protein, S pombe; D012333:RNA, Messenger; C583510:Red5 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; D039221:mRNA Cleavage and Polyadenylation Factors; D063326:Exosome Multienzyme Ribonuclease Complex; C586177:Mtl1 protein, S pombe; D053487:DEAD-box RNA Helicases
keywords: MAGO; MTREC; elF4AIII; exon junction complex; meiosis; splicing