title: A transmembrane protein EIG121L is required for epidermal differentiation during early embryonic development.
abstract: Epidermal differentiation in the ventral ectoderm of Xenopus embryos is regulated by the bone morphogenetic protein (BMP) pathway. However, it remains unclear how the BMP pathway is activated and induces the epidermal fate in the ventral ectoderm. Here, we identify a novel player in the BMP pathway that is required for epidermal differentiation during Xenopus early embryonic development. We show that Xenopus EIG121L (xEIG121L) protein, an evolutionarily conserved transmembrane protein, is expressed in the ventral ectoderm at the gastrula and neurula stages. Almost complete knockdown of xEIG121L protein with antisense morpholino oligonucleotides in early Xenopus embryos results in severe developmental defects, including the inhibition of epidermal differentiation and the induction of neural genes. Remarkably, our analysis shows that BMP/Smad1 signaling is severely suppressed in the xEIG121L knockdown ectoderm. Moreover, immunoprecipitation and immunostaining experiments suggest that xEIG121L protein physically interacts, and co-localizes, with BMP receptors. Thus, our results identify a novel regulator of the BMP pathway that has a positive role in BMP signaling and plays an essential role in epidermal differentiation during early embryonic development.
authors.affiliation: Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Araki
authors.forename: Morioh
authors.initials: M
authors.lastname: Kusakabe
authors.forename: Eisuke
authors.initials: E
authors.lastname: Nishida
mesh_terms: D000818:Animals; D001483:Base Sequence; D052004:Bone Morphogenetic Protein Receptors / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D004475:Ectoderm / Q000378:metabolism*; D047108:Embryonic Development / Q000502:physiology*; D004817:Epidermis / Q000196:embryology*; D005775:Gastrula / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D057809:HEK293 Cells; D006801:Humans; D053505:Matrix Metalloproteinases, Secreted / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D015398:Signal Transduction / Q000502:physiology; D051898:Smad1 Protein / Q000235:genetics / Q000378:metabolism; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis
chemical_list: C557410:KIAA1324L protein, Xenopus; D008565:Membrane Proteins; D051898:Smad1 Protein; D029867:Xenopus Proteins; D052004:Bone Morphogenetic Protein Receptors; D053505:Matrix Metalloproteinases, Secreted