mua-6, a gene required for tissue integrity in Caenorhabditis elegans, encodes a cytoplasmic intermediate filament.
Locomotion in Caenorhabditis elegans requires force transmission through a network of proteins linking the skeletal muscle, via an intervening basal lamina and epidermis (hypodermis), to the cuticle. Mutations in mua-6 result in hypodermal rupture, muscle detachment from the bodywall, and progressive paralysis. It is shown that mua-6 encodes the cytoplasmic intermediate filament (cIF) A2 protein and that a MUA-6/IFA-2::GFP fusion protein that rescues the presumptive mua-6 null allele localizes to hypodermal hemidesmosomes. This result is consistent with what is known about the function of cIFs in vertebrates. Although MUA-6/IFA-2 is expressed embryonically, and plays an essential postembryonic role in tissue integrity, it is not required for embryonic development of muscle-cuticle linkages nor for the localization of other cIFs or hemidesmosome-associated proteins in the embryo. Finally, the molecular lesion in the mua-6(rh85) allele suggests that the head domain of the MUA-6/IFA-2 is dispensable for its function.
Department of Biological Sciences, University of Toledo, Toledo, OH 43606, USA.
Vera
V
Hapiak
Michelle Coutu
MC
Hresko
Lawrence A
LA
Schriefer
Kamlai
K
Saiyasisongkhram
Mark
M
Bercher
John
J
Plenefisch
D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000502:physiology; D017238:Genes, Helminth / Q000502:physiology*; D022002:Hemidesmosomes / Q000737:chemistry; D007381:Intermediate Filament Proteins / Q000235:genetics* / Q000502:physiology
D029742:Caenorhabditis elegans Proteins; D007381:Intermediate Filament Proteins; C000604213:Mua-6 protein, C elegans