QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online 8 April 2004
doi: 10.1242/dev.01063

This Article Figures Only Full Text Full Text (PDF) All Versions of this Article: dev.01063v1 131/9/2073    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Dalpé, G. Articles by Culotti, J. G. Search for Related Content PubMed PubMed Citation Articles by Dalpé, G. Articles by Culotti, J. G. Social Bookmarking                         What's this?

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

¹ Samuel Lunenfeld Research Institute of Mount Sinai Hospital, 600 University Avenue, Toronto M5G 1X5, Canada
² Department of Molecular and Medical Genetics, University of Toronto, Toronto M5S 1A8, Canada

^* Author for correspondence (e-mail: culotti{at}mshri.on.ca)

Accepted 7 January 2004

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.

Key words: Plexins, Migration, RHO-GTPases, C. elegans

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				O. Karakuzu, D. P. Wang, and S. Cameron MIG-32 and SPAT-3A are PRC1 homologs that control neuronal migration in Caenorhabditis elegans Development, March 15, 2009; 136(6): 943 - 953. [Abstract] [Full Text] [PDF]

				A. D. Chisholm Semaphorin signaling in morphogenesis: found in translation Genes & Dev., April 15, 2008; 22(8): 955 - 959. [Abstract] [Full Text] [PDF]

				A. Nukazuka, H. Fujisawa, T. Inada, Y. Oda, and S. Takagi Semaphorin controls epidermal morphogenesis by stimulating mRNA translation via eIF2{alpha} in Caenorhabditis elegans Genes & Dev., April 15, 2008; 22(8): 1025 - 1036. [Abstract] [Full Text] [PDF]

				X. Wang, W. Zhang, T. Cheever, V. Schwarz, K. Opperman, H. Hutter, D. Koepp, and L. Chen The C. elegans L1CAM homologue LAD-2 functions as a coreceptor in MAB-20/Sema2 mediated axon guidance J. Cell Biol., January 10, 2008; 180(1): 233 - 246. [Abstract] [Full Text] [PDF]

				F. Nakao, M. L. Hudson, M. Suzuki, Z. Peckler, R. Kurokawa, Z. Liu, K. Gengyo-Ando, A. Nukazuka, T. Fujii, F. Suto, et al. The Plexin PLX-2 and the Ephrin EFN-4 Have Distinct Roles in MAB-20/Semaphorin 2A Signaling in Caenorhabditis elegans Morphogenesis Genetics, July 1, 2007; 176(3): 1591 - 1607. [Abstract] [Full Text] [PDF]

				J. R. Basile, K. Holmbeck, T. H. Bugge, and J. S. Gutkind MT1-MMP Controls Tumor-induced Angiogenesis through the Release of Semaphorin 4D J. Biol. Chem., March 2, 2007; 282(9): 6899 - 6905. [Abstract] [Full Text] [PDF]

				Y. Yang, J. Lu, J. Rovnak, S. L. Quackenbush, and E. A. Lundquist SWAN-1, a Caenorhabditis elegans WD Repeat Protein of the AN11 Family, Is a Negative Regulator of Rac GTPase Function Genetics, December 1, 2006; 174(4): 1917 - 1932. [Abstract] [Full Text] [PDF]

				M. A. Shakir, J. S. Gill, and E. A. Lundquist Interactions of UNC-34 Enabled With Rac GTPases and the NIK Kinase MIG-15 in Caenorhabditis elegans Axon Pathfinding and Neuronal Migration Genetics, February 1, 2006; 172(2): 893 - 913. [Abstract] [Full Text] [PDF]

				R. McMullan, E. Hiley, P. Morrison, and S. J. Nurrish Rho is a presynaptic activator of neurotransmitter release at pre-existing synapses in C. elegans Genes & Dev., January 1, 2006; 20(1): 65 - 76. [Abstract] [Full Text] [PDF]

				G. Dalpe, L. Brown, and J. G. Culotti Vulva morphogenesis involves attraction of plexin 1-expressing primordial vulva cells to semaphorin 1a sequentially expressed at the vulva midline Development, March 15, 2005; 132(6): 1387 - 1400. [Abstract] [Full Text] [PDF]