Selective elimination of messenger RNA prevents an incidence of untimely meiosis.
Much remains unknown about the molecular regulation of meiosis. Here we show that meiosis-specific transcripts are selectively removed if expressed during vegetative growth in fission yeast. These messenger RNAs contain a cis-acting region--which we call the DSR--that confers this removal via binding to a YTH-family protein Mmi1. Loss of Mmi1 function severely impairs cell growth owing to the untimely expression of meiotic transcripts. Microarray analysis reveals that at least a dozen such meiosis-specific transcripts are eliminated by the DSR-Mmi1 system. Mmi1 remains in the form of multiple nuclear foci during vegetative growth. At meiotic prophase these foci precipitate to a single focus, which coincides with the dot formed by the master meiosis-regulator Mei2. A meiotic arrest due to the loss of the Mei2 dot is released by a reduction in Mmi1 activity. We propose that Mei2 turns off the DSR-Mmi1 system by sequestering Mmi1 to the dot and thereby secures stable expression of meiosis-specific transcripts.
Harigaya
Yuriko
Y
Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, Hongo, Tokyo 113-0033, Japan.
Tanaka
Hirotsugu
H
Yamanaka
Soichiro
S
Tanaka
Kayoko
K
Watanabe
Yoshinori
Y
Tsutsumi
Chihiro
C
Chikashige
Yuji
Y
Hiraoka
Yasushi
Y
Yamashita
Akira
A
Yamamoto
Masayuki
M
D008540:Meiosis / Q000235:genetics*; D008938:Mitosis / Q000235:genetics; D011418:Prophase; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000166:cytology* / Q000235:genetics* / Q000254:growth & development; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D014158:Transcription, Genetic / Q000235:genetics; D039221:mRNA Cleavage and Polyadenylation Factors / Q000235:genetics / Q000378:metabolism
C512176:Mmi1 protein, S pombe; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029702:Schizosaccharomyces pombe Proteins; D039221:mRNA Cleavage and Polyadenylation Factors; C088896:mei2 protein, S pombe; C489539:mei4 protein, S pombe