1887

Abstract

The terminal event of spore differentiation in the cellular slime mould is the assembly of the spore coat, which surrounds the dormant amoeba and allows the organism to survive during extended periods of environmental stress. The spore coat is a polarized extracellular matrix composed of glycoproteins and cellulose. The process of spore coat formation begins by the regulated secretion of spore coat proteins from the prespore vesicles (PSVs). Four of the major spore coat proteins (SP96, PsB/SP85, SP70 and SP60) exist as a preassembled multiprotein complex within the PSVs. This complete complex has an endogenous cellulose-binding activity. Mutant strains lacking either the SP96 or SP70 proteins produce partial complexes that do not have cellulose-binding activity, while mutants lacking SP60 produce a partial complex that retains this activity. Using a combination of immunofluorescence microscopy and biochemical methods we now show that the lack of cellulose-binding activity in the SP96 and SP70 mutants results in abnormally assembled spore coats and spores with greatly reduced viability. In contrast, the SP60 mutant, in which the PsB complex retains its cellulose-binding activity, produces spores with apparently unaltered structure and viability. Thus, it is the loss of the cellulose-binding activity of the PsB complex, rather than the mere loss of individual spore coat proteins, that results in compromised spore coat structure. These results support the idea that the cellulose-binding activity associated with the complete PsB complex plays an active role in the assembly of the spore coat.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-146-8-1829
2000-08-01
2020-09-21
Loading full text...

Full text loading...

/deliver/fulltext/micro/146/8/1461829a.html?itemId=/content/journal/micro/10.1099/00221287-146-8-1829&mimeType=html&fmt=ahah

References

  1. Alexander S.. 1997; Developmental regulation and function of glycoproteins in Dictyostelium discoideum. In Dictyostelium: a Model System for Cell and Developmental Biology pp.349–362Edited by Maeda Y., Inouye K., Takeuchi I.. Tokyo: Universal Academy Press;
    [Google Scholar]
  2. Blanton R. L., Fuller D., Iranfar N., Grimson M. J., Loomis W. F.. 2000; The cellulose synthase gene of Dictyostelium. Proc Natl Acad Sci U S A97:2391–2396[CrossRef]
    [Google Scholar]
  3. Champion A., Gooley A. A., Callaghan M., Carrin M. I., Bernstein R. L., Smith E., Williams K. L.. 1991; Immunodominant carbohydrate determinants in the multicellular stages of Dictyostelium discoideum. J Gen Microbiol137:2431–2438[CrossRef]
    [Google Scholar]
  4. Champion A., Griffiths K., Gooley A. A., Gonzalez B. Y., Gritzali M., West C. M., Williams K. L.. 1995; Immunochemical, genetic and morphological comparison of fucosylation mutants of Dictyostelium discoideum. Microbiology141:785–797[CrossRef]
    [Google Scholar]
  5. Cosgrove D. J.. 1997; Assembly and enlargement of the primary cell wall in plants. Annu Rev Cell Dev Biol13:171–201[CrossRef]
    [Google Scholar]
  6. Delmer D. P.. 1999; Cellulose biosynthesis: Exciting times for a difficult field of study. Annu Rev Plant Physiol Plant Mol Biol50:245–276[CrossRef]
    [Google Scholar]
  7. Devine K. M., Morrissey J. H., Loomis W. F.. 1982; Differential synthesis of spore coat proteins in prespore and prestalk cells of Dictyostelium. Proc Natl Acad Sci U S A79:7361–7365[CrossRef]
    [Google Scholar]
  8. Devine K. M., Bergmann J. E., Loomis W. F.. 1983; Spore coat proteins of Dictyostelium discoideum are packaged in prespore vesicles. Dev Biol99:437–446[CrossRef]
    [Google Scholar]
  9. Ennis H. L., Sussman M.. 1975; Mutants of Dictyostelium discoideum defective in spore germination. J Bacteriol124:62–64
    [Google Scholar]
  10. Erdos G. W., West C. M.. 1989; Formation and organization of the spore coat of Dictyostelium discoideum. Exp Mycol13:169–182[CrossRef]
    [Google Scholar]
  11. Fosnaugh K. L., Fuller D., Loomis W. F.. 1994; Structural roles of the spore coat proteins in Dictyostelium discoideum. Dev Biol166:823–825[CrossRef]
    [Google Scholar]
  12. Grant W. N., Williams K. L.. 1983; Monoclonal antibody characterization of slime sheath: the extracellular matrix of Dictyostelium discoideum. EMBO J2:935–940
    [Google Scholar]
  13. Hemmes D. E., Kojima-Buddenhagen E. S., Hohl H. R.. 1972; Structural and enzymatic analysis of the spore wall layers in Dictyostelium discoideum. J Ultrastruct Res41:406–417[CrossRef]
    [Google Scholar]
  14. Hohl H., Hamamoto S.. 1969; Ultrastructure of spore differentiation in Dictyostelium: the prespore vacuole. J Ultrastruct Res26:442–453[CrossRef]
    [Google Scholar]
  15. Kuspa A., Loomis W. F.. 1994; Transformation of Dictyostelium: Gene disruption, insertional mutagenesis and promoter traps. Methods Mol Genet3:3–21
    [Google Scholar]
  16. Lukashev M. E., Werb Z.. 1998; ECM signalling: orchestrating cell behaviour and misbehaviour. Trends Cell Biol8:437–441[CrossRef]
    [Google Scholar]
  17. McGuire V.. 1996; Assembly and function of the PsB multiprotein complex during spore differentiation in Dictyostelium discoideum PhD thesis University of Missouri; USA:
    [Google Scholar]
  18. McGuire V., Alexander S.. 1996; PsB multiprotein complex of Dictyostelium discoideum: Demonstration of cellulose binding activity and order of protein subunit assembly. J Biol Chem271:14596–14603[CrossRef]
    [Google Scholar]
  19. McNeil M., Darvill A. G., Fry S. C., Albersheim P.. 1984; Structure and function of the primary cell walls of plants. Annu Rev Biochem53:625–663[CrossRef]
    [Google Scholar]
  20. Muhlethaler K.. 1956; Electron microscopic study of the slime mold Dictyostelium discoideum. Am J Botany43:673–677[CrossRef]
    [Google Scholar]
  21. Orlowski M., Loomis W. F.. 1979; Plasma membrane proteins of Dictyostelium: the spore coat proteins. Dev Biol71:297–307[CrossRef]
    [Google Scholar]
  22. Richardson D. L., Loomis W. F.. 1992; Disruption of the sporulation-specific gene SpiA in Dictyostelium discoideum leads to spore instability. Genes Dev6:1058–1070[CrossRef]
    [Google Scholar]
  23. Smith E., Gooley A. A., Hudson G. C., Williams K. L.. 1989; Glycoproteins that exhibit extensive size polymorphisms in Dictyostelium discoideum. Genetics122:59–64
    [Google Scholar]
  24. Srinivasan S., Alexander H., Alexander S.. 1999; The prespore vesicles of Dictyostelium discoideum: Purification, characterization and developmental regulation. J Biol Chem274:35823–35831[CrossRef]
    [Google Scholar]
  25. Srinivasan S., Alexander H., Alexander S.. 2000; Crossing the finish line of development: regulated secretion of Dictyostelium proteins. Trends Cell Biol10:215–219[CrossRef]
    [Google Scholar]
  26. Sussman M.. 1987; Cultivation and synchronous morphogenesis of Dictyostelium under controlled experimental conditions. Methods Cell Biol28:9–29
    [Google Scholar]
  27. Voet L., Krefft M., Bruderlein M., Williams K.. 1985; Flow cytometer study of anterior-like cells in Dictyostelium discoideum. J Cell Sci75:423–435
    [Google Scholar]
  28. Watson N., Williams K. L., Alexander S.. 1993; A developmentally regulated glycoprotein complex from Dictyostelium discoideum. J Biol Chem268:22634–22641
    [Google Scholar]
  29. Watson N., McGuire V., Alexander S.. 1994; The PsB glycoprotein complex is secreted as a preassembled precursor of the spore coat in Dictyostelium discoideum. J Cell Sci107:2567–2579
    [Google Scholar]
  30. West C. M., Erdos G. W.. 1990; Formation of the Dictyostelium spore coat. Dev Genet11:492–506[CrossRef]
    [Google Scholar]
  31. West C. M., Mao J., van der Wel H., Erdos G. W., Zhang Y.. 1996; SP75 is encoded by the DP87 gene and belongs to a family of modular Dictyostelium discoideum outer layer spore coat proteins. Microbiology142:2227–2243[CrossRef]
    [Google Scholar]
  32. Yan J. X., Gooley A. A., Williams K. L.. 1997; The Dictyostelium proteome project: Studying the readout of the genome. In Dictyostelium: a Model System for Cell and Developmental Biology pp.455–469Edited by Maeda Y., Inouye K., Takeuchi I.. Tokyo: Universal Academy Press;
    [Google Scholar]
  33. Zhang Y. Y., Brown R. D., West C. M.. 1998; Two proteins of the Dictyostelium spore coat bind to cellulose in vitro. Biochemistry37:10766–10779[CrossRef]
    [Google Scholar]
  34. Zhang Y., Zhang P., West C. M.. 1999; A linking function for the cellulose-binding protein of SP85 in the spore coat of Dictyostelium discoideum. J Cell Sci112:4367–4377
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-146-8-1829
Loading
/content/journal/micro/10.1099/00221287-146-8-1829
Loading

Data & Media loading...

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