Sinup, a novel Siaz-interacting nuclear protein, modulates neural plate formation in the zebrafish embryos.
Siah, the vertebrate homologue of the Drosophila seven in absentia (sina) gene, is well conserved from Drosophila to mammal and involved in ubiquitination and proteasome-dependent degradation of various target proteins. To identify cellular proteins interacting with Siah, we screened a zebrafish cDNA library with zebrafish Siah (Siaz) as bait in a yeast two-hybrid assay. We identified a cDNA encoding a novel protein composed of 145 amino acids and termed it as Sinup (Siaz-interacting-nuclear-protein). Sinup is a novel nuclear protein that binds to the highly conserved C-terminal protein-interacting domain of Siaz both in vivo and in vitro. During development, sinup transcripts are abundant from the one-cell stage to the early blastula and then markedly diminished, suggesting sinup largely exists as maternal transcripts. sinup overexpression induced lateral expansion of the neural plate and in consequence caused ectopic expression of otx-2 and hoxb1b during the late gastrula stage. In addition, the lateral/paraxial expression of wnt8 at the onset of gastrulation is suppressed by the forced expression of sinup while the expression levels of various dorso-ventral markers are unaffected. In contrast, interfering with sinup functions using sinup morpholino oligonucleotides gradually diminished the anterior neuroectoderm from the posterior region, and resulted in compete loss of hindbrain at the 3-somites stage. Our report suggests that sinup expression should be tightly regulated during early embryonic development for the proper neural plate formation.
Ro
Hyunju
H
School of Bioscience and Biotechnology, College of Natural Sciences, Chungnam National University, Daejeon 305-764, Republic of Korea.
Won
Minho
M
Lee
Su-Ui
SU
Kim
Kyoon E
KE
Huh
Tae-Lin
TL
Kim
Cheol-Hee
CH
Rhee
Myungchull
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000378:metabolism / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000096:biosynthesis; D018076:DNA, Complementary / Q000378:metabolism; D004475:Ectoderm / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D015723:Gene Library; D005982:Glutathione Transferase / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D018398:Homeodomain Proteins / Q000096:biosynthesis; D006801:Humans; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009432:Neural Crest / Q000196:embryology*; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D009841:Oligonucleotides / Q000737:chemistry; D051857:Otx Transcription Factors; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012313:RNA / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection; D020798:Two-Hybrid System Techniques; D044767:Ubiquitin-Protein Ligases; D051153:Wnt Proteins; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology*; D000098563:Seven in Absentia Proteins
D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D018076:DNA, Complementary; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D009841:Oligonucleotides; D051857:Otx Transcription Factors; C502531:Sinup protein, zebrafish; D051153:Wnt Proteins; D029961:Zebrafish Proteins; C094521:wnt8a protein, zebrafish; D049452:Green Fluorescent Proteins; D012313:RNA; D044767:Ubiquitin-Protein Ligases; D000098563:Seven in Absentia Proteins; D005982:Glutathione Transferase