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.
Publication types
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Animals
-
Body Patterning / genetics
-
Caenorhabditis elegans / metabolism*
-
Caenorhabditis elegans / ultrastructure
-
Caenorhabditis elegans Proteins / genetics
-
Caenorhabditis elegans Proteins / isolation & purification
-
Caenorhabditis elegans Proteins / metabolism*
-
Cell Membrane / metabolism*
-
Cell Membrane / ultrastructure
-
Cell Polarity / genetics
-
Cytoskeletal Proteins / genetics
-
Cytoskeletal Proteins / isolation & purification
-
Cytoskeletal Proteins / metabolism*
-
Cytoskeleton / metabolism*
-
Cytoskeleton / ultrastructure
-
Drosophila Proteins / genetics
-
Drosophila Proteins / metabolism
-
Epithelial Cells / metabolism
-
Epithelial Cells / ultrastructure
-
Microscopy, Electron
-
Organogenesis / genetics
-
RNA Interference
-
Saccharomyces cerevisiae Proteins / genetics
-
Saccharomyces cerevisiae Proteins / metabolism
-
Spectrin / genetics
-
Spectrin / metabolism
Substances
-
ARP1 protein, S cerevisiae
-
Caenorhabditis elegans Proteins
-
Cytoskeletal Proteins
-
Drosophila Proteins
-
ERM-1 protein, C elegans
-
Saccharomyces cerevisiae Proteins
-
kst protein, Drosophila
-
Spectrin