title: NumbL is essential for Xenopus primary neurogenesis.
abstract: BACKGROUND
  Members of the vertebrate Numb family of cell fate determinants serve multiple functions throughout early embryogenesis, including an essential role in the development of the nervous system. The Numb proteins interact with various partner proteins and correspondingly participate in multiple cellular activities, including inhibition of the Notch pathway.
  
  
  RESULTS
  Here, we describe the expression characteristics of Numb and Numblike (NumbL) during Xenopus development and characterize the function of NumbL during primary neurogenesis. NumbL, in contrast to Numb, is expressed in the territories of primary neurogenesis and is positively regulated by the Neurogenin family of proneural transcription factors. Knockdown of NumbL afforded a complete loss of primary neurons and did not lead to an increase in Notch signaling in the open neural plate. Furthermore, we provide evidence that interaction of NumbL with the AP-2 complex is required for NumbL function during primary neurogenesis.
  
  
  CONCLUSIONS
  We demonstrate an essential role of NumbL during Xenopus primary neurogenesis and provide evidence for a Notch-independent function of NumbL in this context.
authors.affiliation: Institute of Developmental Biochemistry, University of Goettingen, Goettingen, Germany. khennin1@gwdg.de.
authors.forename: Frank
authors.initials: F
authors.lastname: Nieber
authors.forename: Marie
authors.initials: M
authors.lastname: Hedderich
authors.forename: Olaf
authors.initials: O
authors.lastname: Jahn
authors.forename: Tomas
authors.initials: T
authors.lastname: Pieler
authors.forename: Kristine A
authors.initials: KA
authors.lastname: Henningfeld
mesh_terms: D033962:Adaptor Protein Complex 2 / Q000378:metabolism; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D004625:Embryo, Nonmammalian; D005260:Female; D005786:Gene Expression Regulation; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D020043:Genes, Essential; D051379:Mice; D005810:Multigene Family; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D054258:Neural Plate / Q000378:metabolism; D055495:Neurogenesis / Q000235:genetics / Q000502:physiology*; D009474:Neurons / Q000378:metabolism; D051880:Receptors, Notch / Q000378:metabolism; D015398:Signal Transduction; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014982:Xenopus laevis / Q000196:embryology / Q000235:genetics / Q000378:metabolism*
chemical_list: D033962:Adaptor Protein Complex 2; D051792:Basic Helix-Loop-Helix Proteins; D009419:Nerve Tissue Proteins; D051880:Receptors, Notch; D029867:Xenopus Proteins; C549535:NOTCH1 protein, Xenopus; C000588938:NumbL protein, Xenopus; C101907:neurogenin, Xenopus