TY - JOUR
T1 - Functional significance of nuclear export and mRNA binding of meiotic regulator Spo5 in fission yeast
AU - Togashi, Naoyuki
AU - Yamashita, Akira
AU - Sato, Masamitsu
AU - Yamamoto, Masayuki
N1 - Funding Information:
We are grateful to Drs. Ravi Dhar and Takatomi Yamada for providing the materials. We highly appreciate assistance of Dr. Mayumi Arata and Mr. Yuichi Shichino in quantitative experiments. This work was supported by Grants-in-Aid for Specially Promoted Research and Scientific Research (S) (to M.Y.) and for Scientific Research (C) (to A.Y.) from Japan Society for the Promotion of Science (JSPS), and Grant-in-Aid for Scientific Research on Priority Areas “Cell Proliferation Control” from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) (to M.S.). This work was also supported in part by the Global COE Program (Integrative Life Science Based on the Study of Biosignaling Mechanisms), MEXT, Japan.
PY - 2014/7/15
Y1 - 2014/7/15
N2 - Background: Meiotic cells undergo two rounds of nuclear division and generate gametes. Previous studies have indicated that a number of transcription factors modulate the transcriptome in successive waves during meiosis and spore formation in fission yeast. However, the mechanisms underlying the post-transcriptional regulation in meiosis are not fully understood. The fission yeast spo5 + gene encodes a meiosis-specific RNA-binding protein, which is required for the progression of meiosis II and spore formation. However, the target RNA molecules of Spo5 are yet to be identified. Characterization of meiosis-specific RNA-binding proteins will provide insight into how post-transcriptional regulation influence gene expression during sexual differentiation. Results: To assess the functional significance of RNA-recognition motifs (RRMs) of Spo5, we constructed a series of new spo5 truncated mutants and previously reported spo5 missense mutants. In addition, we isolated novel spo5 missense mutants. The phenotypic characteristics of these mutants indicated that the RRMs are essential for both the localization and function of the protein. Interestingly, Spo5 is exported from the nucleus to the cytoplasm via the Rae1-dependent mRNA export pathway, but is unlikely to be involved in global mRNA export. Furthermore, cytoplasmic localization of Spo5 is important for its function, which suggests the involvement of Spo5 in post-transcriptional regulation. We identified pcr1 + mRNA as one of the critical targets of Spo5. The pcr1 + gene encodes an activating transcription factor/cAMP response element binding (ATF/CREB) transcription factor family. Among the four family members, namely Pcr1, Atf1, Atf21, and Atf31, only the mRNA encoding Pcr1 binds to Spo5. Conclusions: Spo5 is exported from the nucleus with mRNAs via the Rae1-dependent pathway. RRMs are necessary for this process and also for the function of Spo5 after the nuclear export. Spo5 appears to influence the activity of pcr1 + mRNA, and the mechanism of how Spo5 stimulates the mRNA to promote the progression of meiosis II and spore formation remains an intriguing question for future research.
AB - Background: Meiotic cells undergo two rounds of nuclear division and generate gametes. Previous studies have indicated that a number of transcription factors modulate the transcriptome in successive waves during meiosis and spore formation in fission yeast. However, the mechanisms underlying the post-transcriptional regulation in meiosis are not fully understood. The fission yeast spo5 + gene encodes a meiosis-specific RNA-binding protein, which is required for the progression of meiosis II and spore formation. However, the target RNA molecules of Spo5 are yet to be identified. Characterization of meiosis-specific RNA-binding proteins will provide insight into how post-transcriptional regulation influence gene expression during sexual differentiation. Results: To assess the functional significance of RNA-recognition motifs (RRMs) of Spo5, we constructed a series of new spo5 truncated mutants and previously reported spo5 missense mutants. In addition, we isolated novel spo5 missense mutants. The phenotypic characteristics of these mutants indicated that the RRMs are essential for both the localization and function of the protein. Interestingly, Spo5 is exported from the nucleus to the cytoplasm via the Rae1-dependent mRNA export pathway, but is unlikely to be involved in global mRNA export. Furthermore, cytoplasmic localization of Spo5 is important for its function, which suggests the involvement of Spo5 in post-transcriptional regulation. We identified pcr1 + mRNA as one of the critical targets of Spo5. The pcr1 + gene encodes an activating transcription factor/cAMP response element binding (ATF/CREB) transcription factor family. Among the four family members, namely Pcr1, Atf1, Atf21, and Atf31, only the mRNA encoding Pcr1 binds to Spo5. Conclusions: Spo5 is exported from the nucleus with mRNAs via the Rae1-dependent pathway. RRMs are necessary for this process and also for the function of Spo5 after the nuclear export. Spo5 appears to influence the activity of pcr1 + mRNA, and the mechanism of how Spo5 stimulates the mRNA to promote the progression of meiosis II and spore formation remains an intriguing question for future research.
KW - ATF/CREB family
KW - Fission yeast
KW - Meiosis
KW - RNA export
KW - RNA-binding protein
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U2 - 10.1186/1471-2180-14-188
DO - 10.1186/1471-2180-14-188
M3 - Article
C2 - 25023750
AN - SCOPUS:84904087216
SN - 1471-2180
VL - 14
JO - BMC Microbiology
JF - BMC Microbiology
IS - 1
M1 - 188
ER -