title: Monomeric mature protein of Nodal-related 3 activates Xbra expression.
abstract: Nodal and related proteins play central roles in axes formation, mesendoderm induction, neural patterning, and left-right development. However, Xenopus nodal-related 3 (Xnr3) has unique activities in regulating neural induction and convergent extension movements. Xnr3 is distinguished from other transforming growth factor-beta superfamily members by the absence of the seventh conserved cysteine at the C terminus of the protein, and little is known about the molecular mechanism of Xnr3 action. In this study, we report a novel and unique mechanism of action that the mature region of Xenopus tropicalis nodal-related 3 (Xtnr3) functions as a monomer. Comparative analyses between Xtnr3 and Xnr5 revealed regions required for dimerization: (1) a conserved glycine, (2) the seventh cysteine, and (3) a putative alpha-helix located between the third and the fourth cysteines. These results indicate that the mature region of Nodal-related 3 entirely differs from other Nodal-related proteins in its mechanism of action.
authors.affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Haramoto
authors.forename: Shuji
authors.initials: S
authors.lastname: Takahashi
authors.forename: Makoto
authors.initials: M
authors.lastname: Asashima
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D019281:Dimerization; D004625:Embryo, Nonmammalian; D008969:Molecular Sequence Data; D055456:Nodal Signaling Ligands; D017434:Protein Structure, Tertiary / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D020825:T-Box Domain Proteins / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000737:chemistry* / Q000378:metabolism*; D014981:Xenopus; D029867:Xenopus Proteins / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D055456:Nodal Signaling Ligands; D011993:Recombinant Fusion Proteins; D020825:T-Box Domain Proteins; C116765:TBXT protein, Xenopus; D016212:Transforming Growth Factor beta; D029867:Xenopus Proteins; C094620:nodal3.1 protein, Xenopus; C418882:nodal5 protein, Xenopus