title: The minus-end actin capping protein, UNC-94/tropomodulin, regulates development of the Caenorhabditis elegans intestine.
abstract: BACKGROUND
  Tropomodulins are actin-capping proteins that regulate the stability of the slow-growing, minus-ends of actin filaments. The C. elegans tropomodulin homolog, UNC-94, has sequence and functional similarity to vertebrate tropomodulins. We investigated the role of UNC-94 in C. elegans intestinal morphogenesis.
  
  
  RESULTS
  In the embryonic C. elegans intestine, UNC-94 localizes to the terminal web, an actin- and intermediate filament-rich structure that underlies the apical membrane. Loss of UNC-94 function results in areas of flattened intestinal lumen. In worms homozygous for the strong loss-of-function allele, unc-94(tm724), the terminal web is thinner and the amount of F-actin is reduced, pointing to a role for UNC-94 in regulating the structure of the terminal web. The non-muscle myosin, NMY-1, also localizes to the terminal web, and we present evidence that increasing actomyosin contractility by depleting the myosin phosphatase regulatory subunit, mel-11, can rescue the flattened lumen phenotype of unc-94 mutants.
  
  
  CONCLUSIONS
  The data support a model in which minus-end actin capping by UNC-94 promotes proper F-actin structure and contraction in the terminal web, yielding proper shape of the intestinal lumen. This establishes a new role for a tropomodulin in regulating lumen shape during tubulogenesis.
authors.affiliation: Department of Biology, SUNY College at Geneseo, Geneseo, New York.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Cox-Paulson
authors.forename: Vincent
authors.initials: V
authors.lastname: Cannataro
authors.forename: Thomas
authors.initials: T
authors.lastname: Gallagher
authors.forename: Corey
authors.initials: C
authors.lastname: Hoffman
authors.forename: Gary
authors.initials: G
authors.lastname: Mantione
authors.forename: Matthew
authors.initials: M
authors.lastname: Mcintosh
authors.forename: Malan
authors.initials: M
authors.lastname: Silva
authors.forename: Nicole
authors.initials: N
authors.lastname: Vissichelli
authors.forename: Rachel
authors.initials: R
authors.lastname: Walker
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Simske
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Ono
authors.forename: Harold
authors.initials: H
authors.lastname: Hoops
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology*; D007422:Intestines / Q000166:cytology / Q000196:embryology*; D009154:Mutation; D018995:Myosin Heavy Chains / Q000235:genetics / Q000378:metabolism; D051348:Tropomodulin / Q000235:genetics / Q000378:metabolism*
chemical_list: D000199:Actins; D029742:Caenorhabditis elegans Proteins; C480836:NMY-1 protein, C elegans; D051348:Tropomodulin; C480760:UNC-94 protein, C elegans; D018995:Myosin Heavy Chains
keywords: actomyosin contractility; terminal web; tubulogenesis