The PLEXIN PLX-2 and the ephrin EFN-4 have distinct roles in MAB-20/Semaphorin 2A signaling in Caenorhabditis elegans morphogenesis.
Semaphorins are extracellular proteins that regulate axon guidance and morphogenesis by interacting with a variety of cell surface receptors. Most semaphorins interact with plexin-containing receptor complexes, although some interact with non-plexin receptors. Class 2 semaphorins are secreted molecules that control axon guidance and epidermal morphogenesis in Drosophila and Caenorhabditis elegans. We show that the C. elegans class 2 semaphorin MAB-20 binds the plexin PLX-2. plx-2 mutations enhance the phenotypes of hypomorphic mab-20 alleles but not those of mab-20 null alleles, indicating that plx-2 and mab-20 act in a common pathway. Both mab-20 and plx-2 mutations affect epidermal morphogenesis during embryonic and in postembryonic development. In both contexts, plx-2 null mutant phenotypes are much less severe than mab-20 null phenotypes, indicating that PLX-2 is not essential for MAB-20 signaling. Mutations in the ephrin efn-4 do not synergize with mab-20, indicating that EFN-4 may act in MAB-20 signaling. EFN-4 and PLX-2 are coexpressed in the late embryonic epidermis where they play redundant roles in MAB-20-dependent cell sorting.
Nakao
Fumi
F
Division of Biological Science, Nagoya University Graduate School of Science, Nagoya, Japan.
Hudson
Martin L
ML
Suzuki
Motoshi
M
Peckler
Zachary
Z
Kurokawa
Rie
R
Liu
Zhicen
Z
Gengyo-Ando
Keiko
K
Nukazuka
Akira
A
Fujii
Takashi
T
Suto
Fumikazu
F
Shibata
Yukimasa
Y
Shioi
Go
G
Fujisawa
Hajime
H
Mitani
Shohei
S
Chisholm
Andrew D
AD
Takagi
Shin
S
D000818:Animals; D017173:Caenorhabditis elegans / Q000502:physiology; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism* / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000502:physiology*; D036385:Ephrin-A4 / Q000502:physiology*; D008565:Membrane Proteins / Q000378:metabolism*; D009024:Morphogenesis; D009419:Nerve Tissue Proteins / Q000378:metabolism* / Q000502:physiology*; D039961:Semaphorins / Q000378:metabolism*; D015398:Signal Transduction
D029742:Caenorhabditis elegans Proteins; D015815:Cell Adhesion Molecules; D036385:Ephrin-A4; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D039961:Semaphorins; C405025:mab-20 protein, C elegans; C091529:plexin