C. elegans dystroglycan DGN-1 functions in epithelia and neurons, but not muscle, and independently of dystrophin.
The C. elegans dystroglycan (DG) homolog DGN-1 is expressed in epithelia and neurons, and localizes to basement membrane (BM) surfaces. Unlike vertebrate DG, DGN-1 is not expressed in muscle or required for muscle function. dgn-1 null mutants are viable but sterile owing to severe disorganization of the somatic gonad epithelium, and show defects in vulval and excretory cell epithelia and in motoneuron axon guidance. The defects resemble those of epi-1 laminin alphaB mutants, suggesting that DGN-1 serves as a receptor for laminin. dgn-1(0)/+ animals are fertile but show gonad migration defects in addition to the defects seen in homozygotes, indicating that DGN-1 function is dosage sensitive. Phenotypic analyses show that DGN-1 and dystrophin-associated protein complex (DAPC) components have distinct and independent functions, in contrast to the situation in vertebrate muscle. The DAPC-independent functions of DGN-1 in epithelia and neurons suggest that vertebrate DG may also act independently of dystrophin/utrophin in non-muscle tissues.
Johnson
Robert P
RP
Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
Kang
Seong Hoon
SH
Kramer
James M
JM
D000595:Amino Acid Sequence; D000818:Animals; D001485:Basement Membrane / Q000378:metabolism; D001522:Behavior, Animal; D017173:Caenorhabditis elegans / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017124:Conserved Sequence; D049030:Dystroglycans / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016189:Dystrophin / Q000502:physiology*; D004847:Epithelial Cells / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009132:Muscles / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D029742:Caenorhabditis elegans Proteins; C511666:DGN-1 protein, C elegans; D016189:Dystrophin; D011993:Recombinant Fusion Proteins; D049030:Dystroglycans; D049452:Green Fluorescent Proteins