1887

Abstract

RasG-regulated signal transduction has been linked to a variety of growth-specific processes and appears to also play a role in the early development of . In an attempt to uncover some of the molecular components involved in Ras-mediated signalling, several proteins have been described previously, including the cell adhesion molecule DdCAD-1, whose phosphorylation state was affected by the expression of the constitutively activated RasG, RasG(G12T). Here it has been shown that a null strain lacks the phosphoproteins that were tentatively identified as DdCAD-1, confirming its previous designation. Further investigation revealed that cells expressing RasG(G12T) exhibited increased cell–cell cohesion, concomitant with reduced levels of DdCAD-1 phosphorylation. This increased cohesion was DdCAD-1-dependent and was correlated with increased localization of DdCAD-1 at the cell surface. DdCAD-1 phosphorylation was also found to decrease during aggregation. These results revealed a possible role for protein phosphorylation in regulating DdCAD-1-mediated cell adhesion during early development. In addition, the levels of DdCAD-1 protein were substantially reduced in a null cell line. These results indicate that RasG affects both the expression and dephosphorylation of DdCAD-1 during early development.

Loading

Article metrics loading...

/content/journal/micro/10.1099/mic.0.28709-0
2006-05-01
2021-10-25
Loading full text...

Full text loading...

/deliver/fulltext/micro/152/5/1497.html?itemId=/content/journal/micro/10.1099/mic.0.28709-0&mimeType=html&fmt=ahah

References

  1. Beug H., Katz F. E., Stein A., Gerisch G. 1973; Quantitation of membrane sites in aggregating Dictyostelium cells by use of tritiated univalent antibody. Proc Natl Acad Sci U S A 70:3150–3154 [CrossRef]
    [Google Scholar]
  2. Brar S. K., Siu C. H. 1993; Characterization of the cell adhesion molecule gp24 in Dictyostelium discoideum . Mediation of cell–cell adhesion via a Ca2+-dependent mechanism. J Biol Chem 268:24902–24909
    [Google Scholar]
  3. Choi A. H., Siu C. H. 1987; Filopodia are enriched in a cell cohesion molecule of Mr 80,000 and participate in cell–cell contact formation in Dictyostelium discoideum . J Cell Biol 104:1375–1387 [CrossRef]
    [Google Scholar]
  4. Coates J. C., Harwood A. J. 2001; Cell–cell adhesion and signal transduction during Dictyostelium development. J Cell Sci 114:4349–4358
    [Google Scholar]
  5. Faix J., Gerisch G., Noegel A. A. 1992; Overexpression of the csA cell adhesion molecule under its own cAMP-regulated promoter impairs morphogenesis in Dictyostelium . J Cell Sci 102:203–214
    [Google Scholar]
  6. Fukui Y., Yumura S., Yumura-Kitanishi T. 1987; Agar-overlay immuno-fluorescence: high resolution studies of cytoskeletal components and their changes during chemotaxis. Methods Cell Biol 28:347–356
    [Google Scholar]
  7. Gerisch G. 1968; Cell aggregation and differentiation in Dictyostelium . Curr Top Dev Biol 3:157–197
    [Google Scholar]
  8. Jamora C., Fuchs E. 2002; Intercellular adhesion, signalling and the cytoskeleton. Nat Cell Biol 4:E101–E108 [CrossRef]
    [Google Scholar]
  9. Juliano R. L. 2002; Signal transduction by cell adhesion receptors and the cytoskeleton: functions of integrins, cadherins, selectins, and immunoglobulin-superfamily members. Annu Rev Pharmacol Toxicol 42:283–323 [CrossRef]
    [Google Scholar]
  10. Kae H., Lim C. J., Spiegelman G. B., Weeks G. 2004; Chemoattractant-induced Ras activation during Dictyostelium aggregation. EMBO Rep 5:602–606 [CrossRef]
    [Google Scholar]
  11. Kessin R. H. 2001 Dictyostelium – Evolution, Cell Biology, and the Development of Multicellularity Cambridge: Cambridge University Press;
    [Google Scholar]
  12. Khosla M., Spiegelman G. B., Weeks G., Sands T. W., Virdy K. J., Cotter D. A. 1994; RasG protein accumulation occurs just prior to amoebae emergence during spore germination in Dictyostelium discoideum . FEMS Microbiol Lett 117:293–298 [CrossRef]
    [Google Scholar]
  13. Khosla M., Spiegelman G. B., Weeks G. 1996; Overexpression of an activated rasG gene during growth blocks the initiation of Dictyostelium development. Mol Cell Biol 16:4156–4162
    [Google Scholar]
  14. Knecht D. A., Fuller D. L., Loomis W. F. 1987; Surface glycoprotein, gp24, involved in early adhesion of Dictyostelium discoideum . Dev Biol 121:277–283 [CrossRef]
    [Google Scholar]
  15. Lam T. Y., Pickering G., Geltosky J., Siu C. H. 1981; Differential cell cohesiveness expressed by prespore and prestalk cells of Dictyostelium discoideum . Differentiation 20:22–28 [CrossRef]
    [Google Scholar]
  16. Lickert H., Bauer A., Kemler R., Stappert J. 2000; Casein kinase II phosphorylation of E-cadherin increases E-cadherin/ β -catenin interaction and strengthens cell–cell adhesion. J Biol Chem 275:5090–5095 [CrossRef]
    [Google Scholar]
  17. Lilien J., Balsamo J., Arregui C., Xu G. 2002; Turn-off, drop-out: functional state switching of cadherins. Dev Dyn 224:18–29 [CrossRef]
    [Google Scholar]
  18. Lim C. J., Spiegelman G. B., Weeks G. 2001; RasC is required for optimal activation of adenylyl cyclase and Akt/PKB during aggregation. EMBO J 20:4490–4499 [CrossRef]
    [Google Scholar]
  19. Muller K., Gerisch G. 1978; A specific glycoprotein as the target site of adhesion blocking Fab in aggregating Dictyostelium cells. Nature 274:445–449 [CrossRef]
    [Google Scholar]
  20. Nelson W. J., Nusse R. 2004; Convergence of Wnt, beta-catenin, and cadherin pathways. Science 303:1483–1487 [CrossRef]
    [Google Scholar]
  21. Primpke G., Iassonidou V., Nellen W., Wetterauer B. 2000; Role of cAMP-dependent protein kinase during growth and early development of Dictyostelium discoideum . Dev Biol 221:101–111 [CrossRef]
    [Google Scholar]
  22. Secko D. M., Khosla M., Gaudet P., Tsang A., Spiegelman G. B., Weeks G. 2001; RasG regulates discoidin gene expression during Dictyostelium growth. Exp Cell Res 266:135–141 [CrossRef]
    [Google Scholar]
  23. Secko D. M., Insall R. H., Spiegelman G. B., Weeks G. 2004; The identification of Dictyostelium phosphoproteins altered in response to the activation of RasG. Proteomics 4:2629–2639 [CrossRef]
    [Google Scholar]
  24. Sesaki H., Siu C. H. 1996; Novel redistribution of the Ca2+-dependent cell adhesion molecule DdCAD-1 during development of Dictyostelium discoideum . Dev Biol 177:504–516 [CrossRef]
    [Google Scholar]
  25. Sesaki H., Wong E. F., Siu C. H. 1997; The cell adhesion molecule DdCAD-1 in Dictyostelium is targeted to the cell surface by a nonclassical transport pathway involving contractile vacuoles. J Cell Biol 138:939–951 [CrossRef]
    [Google Scholar]
  26. Tuxworth R. I., Cheetham J. L., Machesky L. M., Spiegelmann G. B., Weeks G., Insall R. H. 1997; Dictyostelium RasG is required for normal motility and cytokinesis, but not growth. J Cell Biol 138:605–614 [CrossRef]
    [Google Scholar]
  27. Watts D., Ashworth J. 1970; Growth of myxamoebae of the cellular slime mould Dictyostelium discoideum in axenic culture. Biochem J 119:171–174
    [Google Scholar]
  28. Weeks G., Spiegelman G. B. 2003; Roles played by Ras subfamily proteins in the cell and developmental biology of microorganisms. Cell Signal 15:901–909 [CrossRef]
    [Google Scholar]
  29. Wong E. F., Brar S. K., Sesaki H., Yang C., Siu C. H. 1996; Molecular cloning and characterization of DdCAD-1, a Ca2+-dependent cell–cell adhesion molecule, in Dictyostelium discoideum . J Biol Chem 271:16399–16408 [CrossRef]
    [Google Scholar]
  30. Wong E., Yang C., Wang J., Fuller D., Loomis W. F., Siu C. H. 2002; Disruption of the gene encoding the cell adhesion molecule DdCAD-1 leads to aberrant cell sorting and cell-type proportioning during Dictyostelium development. Development 129:3839–3850
    [Google Scholar]
  31. Yang C., Brar S. K., Desbarats L., Siu C. H. 1997; Synthesis of the Ca2+-dependent cell adhesion molecule DdCAD-1 is regulated by multiple factors during Dictyostelium development. Differentiation 61:275–284 [CrossRef]
    [Google Scholar]
  32. Zeng C., Anjard C., Riemann K., Konzok A., Nellen W. 2000; gdt1, a new signal transduction component for negative regulation of the growth-differentiation transition in Dictyostelium discoideum . Mol Biol Cell 11:1631–1643 [CrossRef]
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/mic.0.28709-0
Loading
/content/journal/micro/10.1099/mic.0.28709-0
Loading

Data & Media loading...

Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error