title: The nodal target gene Xmenf is a component of an FGF-independent pathway of ventral mesoderm induction in Xenopus.
abstract: The interplay of fibroblast growth factor (FGF) and nodal signaling in the Xenopus gastrula marginal zone specifies distinct populations of presumptive mesodermal cells. Cells in the vegetal marginal zone, making up the presumptive leading edge mesoderm, are exposed to nodal signaling, as evidenced by SMAD2 activation, but do not appear to be exposed to FGF signaling, as evidenced by the lack of MAP kinase (MAPK) activation. However, in the animal marginal zone, activation of both SMAD2 and MAPK occurs. The differential activation of these two signaling pathways in the marginal zone results in the vegetal and animal marginal zones expressing different genes at gastrulation, and subsequently having different fates, with the vegetal marginal zone contributing to ventral mesoderm (e.g. ventral blood island) and the animal marginal zone giving rise to dorsal fates (e.g. notochord and somite). We report here the cloning of a cDNA encoding a novel nuclear protein, Xmenf, that is expressed in the vegetal marginal zone. The expression of Xmenf is induced by nodal signaling and negatively regulated by FGF signaling. Results from animal cap studies indicate that Xmenf plays a role in the pathway of ventral mesoderm induction in the vegetal marginal zone.
mesh_terms: D028341:Activins / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D019521:Body Patterning; D019070:Cell Lineage; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D015723:Gene Library; D049452:Green Fluorescent Proteins; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008164:Luminescent Proteins / Q000378:metabolism; D020935:MAP Kinase Signaling System; D008648:Mesoderm / Q000378:metabolism*; D008954:Models, Biological; D008969:Molecular Sequence Data; D055456:Nodal Signaling Ligands; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D010957:Plasmids / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011506:Proteins; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D051899:Smad2 Protein; D013997:Time Factors; D014018:Tissue Distribution; D015534:Trans-Activators / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics; D014981:Xenopus; D029867:Xenopus Proteins / Q000235:genetics / Q000502:physiology*; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D008164:Luminescent Proteins; C113775:Ndr2 protein, vertebrate; D055456:Nodal Signaling Ligands; D009687:Nuclear Proteins; D011500:Protein Synthesis Inhibitors; D011506:Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C485173:STK38L protein, Xenopus; D051899:Smad2 Protein; C497785:Smad2 protein, Xenopus; D015534:Trans-Activators; D016212:Transforming Growth Factor beta; D029867:Xenopus Proteins; C474187:menf.1 protein, Xenopus; D028341:Activins; D049452:Green Fluorescent Proteins; D005346:Fibroblast Growth Factors; D012313:RNA; D001616:beta-Galactosidase