RRC ID 46026
Author Bernadskaya YY, Patel FB, Hsu HT, Soto MC.
Title Arp2/3 promotes junction formation and maintenance in the Caenorhabditis elegans intestine by regulating membrane association of apical proteins.
Journal Mol. Biol. Cell
Abstract It has been proposed that Arp2/3, which promotes nucleation of branched actin, is needed for epithelial junction initiation but is less important as junctions mature. We focus here on how Arp2/3 contributes to the Caenorhabditis elegans intestinal epithelium and find important roles for Arp2/3 in the maturation and maintenance of junctions in embryos and adults. Electron microscope studies show that embryos depleted of Arp2/3 form apical actin-rich microvilli and electron-dense apical junctions. However, whereas apical/basal polarity initiates, apical maturation is defective, including decreased apical F-actin enrichment, aberrant lumen morphology, and reduced accumulation of some apical junctional proteins, including DLG-1. Depletion of Arp2/3 in adult animals leads to similar intestinal defects. The DLG-1/AJM-1 apical junction proteins, and the ezrin-radixin-moesin homologue ERM-1, a protein that connects F-actin to membranes, are required along with Arp2/3 for apical F-actin enrichment in embryos, whereas cadherin junction proteins are not. Arp2/3 affects the subcellular distribution of DLG-1 and ERM-1. Loss of Arp2/3 shifts both ERM-1 and DLG-1 from pellet fractions to supernatant fractions, suggesting a role for Arp2/3 in the distribution of membrane-associated proteins. Thus, Arp2/3 is required as junctions mature to maintain apical proteins associated with the correct membranes.
Volume 22(16)
Pages 2886-99
Published 2011-8-15
DOI 10.1091/mbc.E10-10-0862
PII mbc.E10-10-0862
PMID 21697505
PMC PMC3154884
MeSH Actin-Related Protein 2-3 Complex / genetics Actin-Related Protein 2-3 Complex / metabolism* Actins / metabolism Animals Caenorhabditis elegans / cytology* Caenorhabditis elegans / metabolism Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / metabolism Cell Membrane / metabolism* Cytoskeletal Proteins / metabolism Embryonic Development Intercellular Junctions / metabolism* Intestinal Mucosa / embryology Intestinal Mucosa / metabolism Intestinal Mucosa / ultrastructure Intestines / cytology* Larva / cytology Larva / metabolism Membrane Proteins / metabolism Microscopy, Fluorescence Multiprotein Complexes / genetics Multiprotein Complexes / metabolism Phalloidine / metabolism Phenotype Protein Transport RNA Interference Subcellular Fractions / metabolism
IF 3.905
Times Cited 19
C.elegans tm677