Translational control of maskin mRNA by its 3' untranslated region.
BACKGROUND
Maskin is a member of the TACC (transforming acidic coiled-coil) domain proteins found in Xenopus laevis oocytes and embryos. It has been implicated in the co-ordination of the spindle and has been reported to mediate translational repression of cyclin B1 mRNA.


RESULTS
In the present study, we report that maskin mRNA is translationally repressed at the level of initiation in stage 4 oocytes and becomes activated in stage 6 oocytes. The translational repression of maskin mRNA correlates with the presence of a short poly(A) tail on this mRNA in stage 4 oocytes. The 3'-UTR (untranslated region) of maskin can confer the translational regulation to a reporter mRNA, and so can the 3'-UTR of human TACC3. A conserved GUCU repeat element was found to repress translation in both stage 4 and stage 6 oocytes, but deletion of this element did not abrogate repression in stage 4 oocytes. UV cross-linking experiments indicated that overlapping sets of proteins bind efficiently to both the maskin and the cyclin B1 3'-UTRs. As reported previously, CPEB [CPE (cytoplasmic polyadenylation element)-binding protein] binds to the cyclin B1 3'-UTR, but its binding to the maskin 3'-UTR is minimal. By RNA affinity chromatography and MS, we identified the EDEN-BP [EDEN (embryonic deadenylation element)-binding protein] as one of the proteins binding to both the maskin and the cyclin B1 3'-UTRs.


CONCLUSIONS
Maskin mRNA is translationally regulated by at least two repressor elements and an activation element. One of the repessor elements is the evolutionarily conserved GUCU repeat. EDEN-BP binds to both the maskin and cyclin B1 3'-UTRs, indicating it may be involved in the deadenylation of these mRNAs.
Meijer
Hedda A
HA
School of Pharmacy, University of Nottingham, University Park, Nottingham, UK.
Radford
Helois E
HE
Wilson
Lolita S
LS
Lissenden
Sarah
S
de Moor
Cornelia H
CH
D020413:3' Untranslated Regions / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019926:Cyclin B / Q000378:metabolism; D056744:Cyclin B1; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism; D009866:Oogenesis; D011061:Poly A / Q000378:metabolism; D011132:Polyribosomes / Q000378:metabolism; D011485:Protein Binding; D014176:Protein Biosynthesis / Q000235:genetics*; D016601:RNA-Binding Proteins / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D012097:Repressor Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics*; D029867:Xenopus Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014982:Xenopus laevis / Q000235:genetics*
D020413:3' Untranslated Regions; C534699:CCNB1 protein, human; D019926:Cyclin B; D056744:Cyclin B1; C110462:EDEN-specific RNA-binding protein, Xenopus; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; C474872:TACC3 protein, Xenopus; D014157:Transcription Factors; D029867:Xenopus Proteins; D011061:Poly A