title: Lumen morphogenesis in C. elegans requires the membrane-cytoskeleton linker erm-1.
abstract: Epithelial tubes are basic building blocks of complex organs, but their architectural requirements are not well understood. Here we show that erm-1 is a unique C. elegans ortholog of the ERM family of cytoskeleton-membrane linkers, with an essential role in lumen morphogenesis. ERM-1 localizes to the luminal membranes of those tubular organ epithelia which lack stabilization by cuticle. RNA interference (RNAi), a germline deletion, and overexpression of erm-1 cause cystic luminal phenotypes in these epithelia. Confocal and ultrastructural analyses indicate that erm-1 functions directly in apical membrane morphogenesis, rather than in epithelial polarity and junction assembly as has been previously proposed for ERMs. We also show that act-5/cytoplasmic actin and sma-1/beta-H-spectrin are required for lumen formation and functionally interact with erm-1. Our findings suggest that there are common structural constraints on the architecture of diverse organ lumina.
authors.affiliation: Laboratory of Developmental Immunology, Massachusetts General Hospital and Department of Pediatrics, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA. gobel@helix.mgh.harvard.edu
authors.forename: Verena
authors.initials: V
authors.lastname: Göbel
authors.forename: Peter L
authors.initials: PL
authors.lastname: Barrett
authors.forename: David H
authors.initials: DH
authors.lastname: Hall
authors.forename: John T
authors.initials: JT
authors.lastname: Fleming
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics; D017173:Caenorhabditis elegans / Q000378:metabolism* / Q000648:ultrastructure; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure; D016764:Cell Polarity / Q000235:genetics; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism* / Q000648:ultrastructure; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism / Q000648:ultrastructure; D008854:Microscopy, Electron; D038081:Organogenesis / Q000235:genetics; D034622:RNA Interference; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D013049:Spectrin / Q000235:genetics / Q000378:metabolism
chemical_list: C089021:ARP1 protein, S cerevisiae; D029742:Caenorhabditis elegans Proteins; D003598:Cytoskeletal Proteins; D029721:Drosophila Proteins; C488174:ERM-1 protein, C elegans; D029701:Saccharomyces cerevisiae Proteins; C112961:kst protein, Drosophila; D013049:Spectrin