PMID- 15073148
OWN - NLM
STAT- MEDLINE
DCOM- 20040702
LR  - 20191210
IS  - 0950-1991 (Print)
IS  - 0950-1991 (Linking)
VI  - 131
IP  - 9
DP  - 2004 May
TI  - Conversion of cell movement responses to Semaphorin-1 and Plexin-1 from 
      attraction to repulsion by lowered levels of specific RAC GTPases in C. elegans.
PG  - 2073-88
AB  - Plexins are functional receptors for Semaphorin axon guidance cues. Previous 
      studies have established that some Plexins directly bind RAC(GTP) and RHO. Recent 
      work in C. elegans showed that semaphorin 1 (smp-1 and smp-2) and plexin 1 
      (plx-1) are required to prevent anterior displacement of the ray 1 cells in the 
      male tail (Fujii et al., 2002; Ginzburg et al., 2002). We show genetically that 
      plx-1 is part of the same functional pathway as smp-1 and smp-2 for male ray 
      positioning. RAC GTPase genes mig-2 and ced-10 probably function redundantly, 
      whereas unc-73, which encodes a GEF for both of these GTPases, is required cell 
      autonomously for preventing anterior displacement of ray 1 cells. RNAi analysis 
      indicates that rho-1-encoded RHO GTPase, plus let-502 and K08B12.5-encoded 
      RHO-kinases, are also required to prevent anterior displacement of ray 1 cells, 
      suggesting that different kinds of RHO-family GTPases act similarly in ray 1 
      positioning. At low doses of wild-type mig-2 and ced-10, the Semaphorin 1 
      proteins no longer act through PLX-1 to prevent anterior displacements of ray 1, 
      but have the opposite effect, acting through PLX-1 to mediate anterior 
      displacements of ray 1. These results suggest that Plexin 1 senses levels of 
      distinct RHO and RAC GTPases. At normal levels of RHO and RAC, Semaphorin 1 
      proteins and PLX-1 prevent a forward displacement of ray 1 cells, whereas at low 
      levels of cycling RAC, Semaphorin 1 proteins and PLX-1 actively mediate their 
      anterior displacement. Endogenously and ectopically expressed SMP-1 and SMP-2 
      suggest that the hook, a major source of Semaphorin 1 proteins in the male tail, 
      normally attracts PLX-1-expressing ray 1 cells.
FAU - Dalpe, Gratien
AU  - Dalpe G
AD  - Samuel Lunenfeld Research Institute of Mount Sinai Hospital, 600 University 
      Avenue, Toronto M5G 1X5, Canada.
FAU - Zhang, Lijia W
AU  - Zhang LW
FAU - Zheng, Hong
AU  - Zheng H
FAU - Culotti, Joseph G
AU  - Culotti JG
LA  - eng
GR  - NS41397/NS/NINDS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
DEP - 20040408
PL  - England
TA  - Development
JT  - Development (Cambridge, England)
JID - 8701744
RN  - 0 (Caenorhabditis elegans Proteins)
RN  - 0 (Cell Adhesion Molecules)
RN  - 0 (Nerve Tissue Proteins)
RN  - 0 (Recombinant Fusion Proteins)
RN  - 0 (Semaphorins)
RN  - 0 (plexin)
RN  - EC 3.6.5.2 (rac GTP-Binding Proteins)
RN  - EC 3.6.5.2 (rho GTP-Binding Proteins)
SB  - IM
MH  - Amino Acid Sequence
MH  - Animals
MH  - *Body Patterning
MH  - COS Cells
MH  - Caenorhabditis elegans/anatomy & histology/*metabolism
MH  - Caenorhabditis elegans Proteins/genetics/*metabolism
MH  - Cell Adhesion Molecules/genetics/*metabolism
MH  - Cell Movement/*physiology
MH  - Chlorocebus aethiops
MH  - Genes, Reporter
MH  - Male
MH  - Molecular Sequence Data
MH  - Nerve Tissue Proteins/genetics/*metabolism
MH  - Protein Biosynthesis
MH  - RNA Interference
MH  - Recombinant Fusion Proteins/genetics/metabolism
MH  - Semaphorins/genetics/*metabolism
MH  - Sequence Alignment
MH  - Signal Transduction/physiology
MH  - Transcription, Genetic
MH  - Transgenes
MH  - rac GTP-Binding Proteins/*metabolism
MH  - rho GTP-Binding Proteins/genetics/metabolism
EDAT- 2004/04/10 05:00
MHDA- 2004/07/03 05:00
CRDT- 2004/04/10 05:00
PHST- 2004/04/10 05:00 [pubmed]
PHST- 2004/07/03 05:00 [medline]
PHST- 2004/04/10 05:00 [entrez]
AID - dev.01063 [pii]
AID - 10.1242/dev.01063 [doi]
PST - ppublish
SO  - Development. 2004 May;131(9):2073-88. doi: 10.1242/dev.01063. Epub 2004 Apr 8.