title: Kcnip1 a Ca²⁺-dependent transcriptional repressor regulates the size of the neural plate in Xenopus.
abstract: In amphibian embryos, our previous work has demonstrated that calcium transients occurring in the dorsal ectoderm at the onset of gastrulation are necessary and sufficient to engage the ectodermal cells into a neural fate by inducing neural specific genes. Some of these genes are direct targets of calcium. Here we search for a direct transcriptional mechanism by which calcium signals are acting. The only known mechanism responsible for a direct action of calcium on gene transcription involves an EF-hand Ca²⁺ binding protein which belongs to a group of four proteins (Kcnip1 to 4). Kcnip protein can act in a Ca²⁺-dependent manner as a transcriptional repressor by binding to a specific DNA sequence, the Downstream Regulatory Element (DRE) site. In Xenopus, among the four kcnips, we show that only kcnip1 is timely and spatially present in the presumptive neural territories and is able to bind DRE sites in a Ca²⁺-dependent manner. The loss of function of kcnip1 results in the expansion of the neural plate through an increased proliferation of neural progenitors. Later on, this leads to an impairment in the development of anterior neural structures. We propose that, in the embryo, at the onset of neurogenesis Kcnip1 is the Ca²⁺-dependent transcriptional repressor that controls the size of the neural plate. This article is part of a Special Issue entitled: 13th European Symposium on Calcium.
authors.affiliation: Université Toulouse 3, Centre de Biologie du Développement, 118 routes de Narbonne, F31062 Toulouse, Cedex 04, France; CNRS UMR5547, Toulouse F31062 France; GDRE CNRS, n° 731, Toulouse, France; Centro Nacional de Biotechnología, CSIC, Madrid, Spain; CIBERNED, Madrid, Spain.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Néant
authors.affiliation: Centro Nacional de Biotechnología, CSIC, Madrid, Spain; CIBERNED, Madrid, Spain.
authors.forename: Britt
authors.initials: B
authors.lastname: Mellström
authors.affiliation: Centro Nacional de Biotechnología, CSIC, Madrid, Spain; CIBERNED, Madrid, Spain.
authors.forename: Paz
authors.initials: P
authors.lastname: Gonzalez
authors.affiliation: GDRE CNRS, n° 731, Toulouse, France; Centro Nacional de Biotechnología, CSIC, Madrid, Spain; CIBERNED, Madrid, Spain.
authors.forename: Jose R
authors.initials: JR
authors.lastname: Naranjo
authors.affiliation: Université Toulouse 3, Centre de Biologie du Développement, 118 routes de Narbonne, F31062 Toulouse, Cedex 04, France; CNRS UMR5547, Toulouse F31062 France; GDRE CNRS, n° 731, Toulouse, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Moreau
authors.affiliation: Université Toulouse 3, Centre de Biologie du Développement, 118 routes de Narbonne, F31062 Toulouse, Cedex 04, France; CNRS UMR5547, Toulouse F31062 France; GDRE CNRS, n° 731, Toulouse, France. Electronic address: catherine.leclerc@univ-tlse3.fr.
authors.forename: Catherine
authors.initials: C
authors.lastname: Leclerc
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology*; D051605:Kv Channel-Interacting Proteins / Q000235:genetics / Q000378:metabolism*; D054258:Neural Plate / Q000166:cytology / Q000196:embryology*; D055495:Neurogenesis / Q000502:physiology; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D020218:Response Elements; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis
chemical_list: D051605:Kv Channel-Interacting Proteins; D012097:Repressor Proteins; D029867:Xenopus Proteins; D002118:Calcium
keywords: Ca(2+) signaling; DREAM; Early neurogenesis; Embryo; KChIP; Neural plate; Xenopus laevis; kcnip