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Smicl (Smad-interacting CPSF 30-like) is an unusual protein that interacts with transcription factors as well as with the cleavage and polyadenylation specificity factor (CPSF). Previous work has shown that Smicl is expressed maternally in the Xenopus embryo and is later required for transcription of Chordin. In this paper we search for additional targets of Smicl. We identify many genes whose onset of expression at the midblastula transition (MBT) requires Smicl and is correlated with the translocation of Smicl from cytoplasm to nucleus. At least one such gene, Xiro1, is regulated via 3'-end processing. In searching for a general mechanism by which Smicl might regulate gene expression at the MBT, we have discovered that it interacts with the tail of Rpb1, the largest subunit of RNA polymerase II. Our results show that Smicl is required for the phosphorylation of the Rpb1 tail at serine 2 of the repeated heptapeptide YSPTSPS. This site becomes hyperphosphorylated at the MBT, thus allowing the docking of proteins required for elongation of transcription and RNA processing. Our work links the onset of zygotic gene expression in the Xenopus embryo with the translocation of Smicl from cytoplasm to nucleus, the phosphorylation of Rpb1 and the 3'-end processing of newly transcribed mRNAs.
Barrandon,
Non-coding RNAs regulating the transcriptional machinery.
2008, Pubmed
Barrandon,
Non-coding RNAs regulating the transcriptional machinery.
2008,
Pubmed Bushati,
Temporal reciprocity of miRNAs and their targets during the maternal-to-zygotic transition in Drosophila.
2008,
Pubmed Chalmers,
A Xenopus tropicalis oligonucleotide microarray works across species using RNA from Xenopus laevis.
2005,
Pubmed
,
Xenbase Collart,
The novel Smad-interacting protein Smicl regulates Chordin expression in the Xenopus embryo.
2005,
Pubmed
,
Xenbase Collart,
Smicl is a novel Smad interacting protein and cleavage and polyadenylation specificity factor associated protein.
2005,
Pubmed Down,
NestedMICA: sensitive inference of over-represented motifs in nucleic acid sequence.
2005,
Pubmed Dreyer,
Differential accumulation of oocyte nuclear proteins by embryonic nuclei of Xenopus.
1987,
Pubmed
,
Xenbase Egloff,
Cracking the RNA polymerase II CTD code.
2008,
Pubmed Ferg,
The TATA-binding protein regulates maternal mRNA degradation and differential zygotic transcription in zebrafish.
2007,
Pubmed Gilchrist,
Defining a large set of full-length clones from a Xenopus tropicalis EST project.
2004,
Pubmed
,
Xenbase Giraldez,
Zebrafish MiR-430 promotes deadenylation and clearance of maternal mRNAs.
2006,
Pubmed Gómez-Skarmeta,
Xiro, a Xenopus homolog of the Drosophila Iroquois complex genes, controls development at the neural plate.
1998,
Pubmed
,
Xenbase Graindorge,
Identification of post-transcriptionally regulated Xenopus tropicalis maternal mRNAs by microarray.
2006,
Pubmed
,
Xenbase Hirose,
RNA polymerase II is an essential mRNA polyadenylation factor.
1998,
Pubmed Hirose,
Phosphorylated RNA polymerase II stimulates pre-mRNA splicing.
1999,
Pubmed Hirose,
Phosphorylation of the C-terminal domain of RNA polymerase II plays central roles in the integrated events of eucaryotic gene expression.
2007,
Pubmed Kimelman,
The events of the midblastula transition in Xenopus are regulated by changes in the cell cycle.
1987,
Pubmed
,
Xenbase Lemaitre,
Dynamics of the genome during early Xenopus laevis development: karyomeres as independent units of replication.
1998,
Pubmed
,
Xenbase Li,
Xenopus NF-Y pre-sets chromatin to potentiate p300 and acetylation-responsive transcription from the Xenopus hsp70 promoter in vivo.
1998,
Pubmed
,
Xenbase Nag,
The poly(A)-dependent transcriptional pause is mediated by CPSF acting on the body of the polymerase.
2007,
Pubmed Newport,
A major developmental transition in early Xenopus embryos: II. Control of the onset of transcription.
1982,
Pubmed
,
Xenbase Newport,
A major developmental transition in early Xenopus embryos: I. characterization and timing of cellular changes at the midblastula stage.
1982,
Pubmed
,
Xenbase Orford,
The maternal CCAAT box transcription factor which controls GATA-2 expression is novel and developmentally regulated and contains a double-stranded-RNA-binding subunit.
1998,
Pubmed
,
Xenbase Ovsenek,
Analysis of CCAAT box transcription factor binding activity during early Xenopus laevis embryogenesis.
1991,
Pubmed
,
Xenbase Palancade,
Incomplete RNA polymerase II phosphorylation in Xenopus laevis early embryos.
2001,
Pubmed
,
Xenbase Peng,
Undamaged DNA transmits and enhances DNA damage checkpoint signals in early embryos.
2007,
Pubmed
,
Xenbase Peterlin,
Controlling the elongation phase of transcription with P-TEFb.
2006,
Pubmed Pfaffl,
A new mathematical model for relative quantification in real-time RT-PCR.
2001,
Pubmed Piepenburg,
Activin redux: specification of mesodermal pattern in Xenopus by graded concentrations of endogenous activin B.
2004,
Pubmed
,
Xenbase Ramis,
Xnrs and activin regulate distinct genes during Xenopus development: activin regulates cell division.
2007,
Pubmed
,
Xenbase Rosonina,
Analysis of the requirement for RNA polymerase II CTD heptapeptide repeats in pre-mRNA splicing and 3'-end cleavage.
2004,
Pubmed Schier,
The maternal-zygotic transition: death and birth of RNAs.
2007,
Pubmed Slack,
Regional biosynthetic markers in the early amphibian embryo.
1984,
Pubmed
