Caenorhabditis elegans PlexinA, PLX-1, interacts with transmembrane semaphorins and regulates epidermal morphogenesis.
The plexin family transmembrane proteins are putative receptors for semaphorins, which are implicated in the morphogenesis of animal embryos, including axonal guidance. We have generated and characterized putative null mutants of the C. elegans plexinA gene, plx-1. plx-1 mutants exhibited morphological defects: displacement of ray 1 and discontinuous alae. The epidermal precursors for the affected organs were aberrantly arranged in the mutants, and a plx-1::gfp transgene was expressed in these epidermal precursor cells as they underwent dynamic morphological changes. Suppression of C. elegans transmembrane semaphorins, Ce-Sema-1a and Ce-Sema-1b, by RNA interference caused a displacement of ray 1 similar to that of plx-1 mutants, whereas mutants for the Ce-Sema-2a/mab-20 gene, which encodes a secreted-type semaphorin, exhibited phenotypes distinct from those of plx-1 mutants. A heterologous expression system showed that Ce-Sema-1a, but not Ce-Sema-2a, physically bound to PLX-1. Our results indicate that PLX-1 functions as a receptor for transmembrane-type semaphorins, and, though Ce-Sema-2a and PLX-1 both play roles in the regulation of cellular morphology during epidermal morphogenesis, they function rather independently.
Fujii
Takashi
T
Division of Biological Science, Nagoya University Graduate School of Science, Chikusa-ku, Nagoya 464-8602, Japan.
Nakao
Fumi
F
Shibata
Yukimasa
Y
Shioi
Go
G
Kodama
Eiji
E
Fujisawa
Hajime
H
Takagi
Shin
S
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans / Q000235:genetics / Q000254:growth & development* / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000502:physiology*; D015816:Cell Adhesion Molecules, Neuronal / Q000502:physiology*; D018076:DNA, Complementary / Q000235:genetics; D018509:DNA, Helminth / Q000235:genetics; D004817:Epidermis / Q000254:growth & development; D015870:Gene Expression; D017238:Genes, Helminth; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000502:physiology*; D010641:Phenotype; D011956:Receptors, Cell Surface / Q000235:genetics / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000235:genetics; D039961:Semaphorins; D017386:Sequence Homology, Amino Acid; D013623:Tail / Q000254:growth & development
D029742:Caenorhabditis elegans Proteins; D015816:Cell Adhesion Molecules, Neuronal; D018076:DNA, Complementary; D018509:DNA, Helminth; D008164:Luminescent Proteins; D009419:Nerve Tissue Proteins; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; D039961:Semaphorins; C492117:plx-1 protein, C elegans; D049452:Green Fluorescent Proteins