Spindle-localized CPE-mediated translation controls meiotic chromosome segregation.
Meiotic progression requires the translational activation of stored maternal mRNAs, such as those encoding cyclin B1 or mos. The translation of these mRNAs is regulated by the cytoplasmic polyadenylation element (CPE) present in their 3'UTRs, which recruits the CPE-binding protein CPEB. This RNA-binding protein not only dictates the timing and extent of translational activation by cytoplasmic polyadenylation but also participates, together with the translational repressor Maskin, in the transport and localization, in a quiescent state, of its targets to subcellular locations where their translation will take place. During the early development of Xenopus laevis, CPEB localizes at the animal pole of oocytes and later on at embryonic spindles and centrosomes. Disruption of embryonic CPEB-mediated translational regulation results in abnormalities in the mitotic apparatus and inhibits embryonic mitosis. Here we show that spindle-localized translational activation of CPE-regulated mRNAs, encoding for proteins with a known function in spindle assembly and chromosome segregation, is essential for completion of the first meiotic division and for chromosome segregation in Xenopus oocytes.
Centre for Genomic Regulation (CRG), C/ Dr. Aiguader, 88, 08003 Barcelona, Spain.
Carolina
C
Eliscovich
Isabel
I
Peset
Isabelle
I
Vernos
Raúl
R
Méndez
D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D020090:Chromosome Segregation; D019926:Cyclin B / Q000235:genetics / Q000378:metabolism; D056744:Cyclin B1; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D016547:Kinesins / Q000235:genetics / Q000378:metabolism; D008540:Meiosis / Q000502:physiology*; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D009865:Oocytes / Q000166:cytology / Q000502:physiology; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D026723:Polyadenylation; D014176:Protein Biosynthesis; D017231:Proto-Oncogene Proteins c-mos / Q000235:genetics / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D008941:Spindle Apparatus / Q000378:metabolism*; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism; D014982:Xenopus laevis / Q000196:embryology
D018797:Cell Cycle Proteins; D019926:Cyclin B; D056744:Cyclin B1; D004268:DNA-Binding Proteins; C490913:KIFF22 protein, Xenopus; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; C486551:TPX2 protein, Xenopus; D029867:Xenopus Proteins; C495329:Mos protein, Xenopus; D017231:Proto-Oncogene Proteins c-mos; D016547:Kinesins