Skip to main content
The Journal of Cell Biology logoLink to The Journal of Cell Biology
. 1988 Jul 1;107(1):177–189. doi: 10.1083/jcb.107.1.177

Monoclonal antibodies directed against the sexual binding site of Chlamydomonas eugametos gametes

PMCID: PMC2115178  PMID: 3292540

Abstract

Monoclonal antibodies were raised against the mt- sexual agglutinin of Chlamydomonas eugametos gametes. Those that blocked the agglutination site were selected. They were divided into two classes dependent upon whether they gave a weak (class A) or clear positive (class B) reaction with mt- flagellar membranes in an ELISA and an indirect immunofluorescence test using glutaraldehyde-fixed mt- gametes. Class A antibodies were shown to be specific for the agglutinin in an extract of mt- gametes, based on results from immunoblotting, immunoprecipitation, affinity chromatography, and the absence of a reaction with nonagglutinable cells. Surprisingly, class A mAbs also recognized two mt+ glycoproteins, one of which is the mt+ agglutinin. Class B antibodies were shown to bind to several glycoproteins in both mt- and mt+ gametes, including the mt- agglutinin. Fab fragments from class A mAbs blocked the sexual agglutination process, but those from class B did not, even though the parent antibody did. We conclude that the class A epitope lies in or close to the agglutination site of the mt- agglutinin, whereas the class B epitope lies elsewhere on the molecule. We also conclude that the mt- agglutinin is the only component on the mt- flagellar surface directly involved in agglutination. Class A mAbs were found to elicit several reactions displayed by the mt+ agglutinin. They bound to the mt- agglutinin on gamete flagella and induced most of the reactions typical of sexual agglutination, with the exception of flagellar tip activation. None of these reactions was induced by Fab fragments. High concentrations of class A mAbs completely repressed the sexual competence of live mt- gametes, but low concentrations stimulated cell fusion.

Full Text

The Full Text of this article is available as a PDF (3.5 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Adair W. S. Characterization of Chlamydomonas sexual agglutinins. J Cell Sci Suppl. 1985;2:233–260. doi: 10.1242/jcs.1985.supplement_2.13. [DOI] [PubMed] [Google Scholar]
  2. Adair W. S., Hwang C., Goodenough U. W. Identification and visualization of the sexual agglutinin from the mating-type plus flagellar membrane of Chlamydomonas. Cell. 1983 May;33(1):183–193. doi: 10.1016/0092-8674(83)90347-1. [DOI] [PubMed] [Google Scholar]
  3. Bennett V. The membrane skeleton of human erythrocytes and its implications for more complex cells. Annu Rev Biochem. 1985;54:273–304. doi: 10.1146/annurev.bi.54.070185.001421. [DOI] [PubMed] [Google Scholar]
  4. Bloodgood R. A. Motility occurring in association with the surface of the Chlamydomonas flagellum. J Cell Biol. 1977 Dec;75(3):983–989. doi: 10.1083/jcb.75.3.983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Bloodgood R. A., Woodward M. P., Salomonsky N. L. Redistribution and shedding of flagellar membrane glycoproteins visualized using an anti-carbohydrate monoclonal antibody and concanavalin A. J Cell Biol. 1986 May;102(5):1797–1812. doi: 10.1083/jcb.102.5.1797. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Claes H. Autolyse der Zellwand bei den Gemeten von Chlamydomonas reinhardii. Arch Mikrobiol. 1971;78(2):180–188. [PubMed] [Google Scholar]
  7. Claes H. Non-specific stimulation of the autolytic system in gametes from Chlamydomonas reinhardii. Exp Cell Res. 1977 Aug;108(1):221–229. [PubMed] [Google Scholar]
  8. Collin-Osdoby P., Adair W. S. Characterization of the purified Chlamydomonas minus agglutinin. J Cell Biol. 1985 Sep;101(3):1144–1152. doi: 10.1083/jcb.101.3.1144. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Collin-Osdoby P., Adair W. S., Goodenough U. W. Chlamydomonas agglutinin conjugated to agarose beads as an in vitro probe of adhesion. Exp Cell Res. 1984 Feb;150(2):282–291. doi: 10.1016/0014-4827(84)90570-6. [DOI] [PubMed] [Google Scholar]
  10. Cooper J. B., Adair W. S., Mecham R. P., Heuser J. E. Chlamydomonas agglutinin is a hydroxyproline-rich glycoprotein. Proc Natl Acad Sci U S A. 1983 Oct;80(19):5898–5901. doi: 10.1073/pnas.80.19.5898. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Forest C. L. Specific contact between mating structure membranes observed in conditional fusion-defective Chlamydomonas mutants. Exp Cell Res. 1983 Oct;148(1):143–154. doi: 10.1016/0014-4827(83)90194-5. [DOI] [PubMed] [Google Scholar]
  12. Goodenough U. W., Adair W. S., Collin-Osdoby P., Heuser J. E. Structure of the Chlamydomonas agglutinin and related flagellar surface proteins in vitro and in situ. J Cell Biol. 1985 Sep;101(3):924–941. doi: 10.1083/jcb.101.3.924. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Goodenough U. W., Jurivich D. Tipping and mating-structure activation induced in Chlamydomonas gametes by flagellar membrane antisera. J Cell Biol. 1978 Dec;79(3):680–693. doi: 10.1083/jcb.79.3.680. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Hoffman J. L., Goodenough U. W. Experimental dissection of flagellar surface motility in Chlamydomonas. J Cell Biol. 1980 Aug;86(2):656–665. doi: 10.1083/jcb.86.2.656. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Klis F. M., Samson M. R., Touw E., Musgrave A., van den Ende H. Sexual Agglutination in the Unicellular Green Alga Chlamydomonas eugametos: Identification and Properties of the Mating Type plus Agglutination Factor. Plant Physiol. 1985 Nov;79(3):740–745. doi: 10.1104/pp.79.3.740. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Kolk A. H., Ho M. L., Klatser P. R., Eggelte T. A., Kuijper S., de Jonge S., van Leeuwen J. Production and characterization of monoclonal antibodies to Mycobacterium tuberculosis, M. bovis (BCG) and M. leprae. Clin Exp Immunol. 1984 Dec;58(3):511–521. [PMC free article] [PubMed] [Google Scholar]
  17. Kooijman R., de Wildt P., Homan W. L., Musgrave A., van den Ende H. Light Affects Flagellar Agglutinability in Chlamydomonas eugametos by Modification of the Agglutinin Molecules. Plant Physiol. 1988 Jan;86(1):216–223. doi: 10.1104/pp.86.1.216. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Mesland D. A., Hoffman J. L., Caligor E., Goodenough U. W. Flagellar tip activation stimulated by membrane adhesions in Chlamydomonas gametes. J Cell Biol. 1980 Mar;84(3):599–617. doi: 10.1083/jcb.84.3.599. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Mesland D. A. Mating in Chlamydomonas eugametos. A scanning electron microscopical study. Arch Microbiol. 1976 Aug;109(1-2):31–35. doi: 10.1007/BF00425109. [DOI] [PubMed] [Google Scholar]
  20. Morrissey J. H. Silver stain for proteins in polyacrylamide gels: a modified procedure with enhanced uniform sensitivity. Anal Biochem. 1981 Nov 1;117(2):307–310. doi: 10.1016/0003-2697(81)90783-1. [DOI] [PubMed] [Google Scholar]
  21. Schneider C., Newman R. A., Sutherland D. R., Asser U., Greaves M. F. A one-step purification of membrane proteins using a high efficiency immunomatrix. J Biol Chem. 1982 Sep 25;257(18):10766–10769. [PubMed] [Google Scholar]
  22. Snell W. J., Kosfiszer M. G., Clausell A., Perillo N., Imam S., Hunnicutt G. A monoclonal antibody that blocks adhesion of Chlamydomonas mt+ gametes. J Cell Biol. 1986 Dec;103(6 Pt 1):2449–2456. doi: 10.1083/jcb.103.6.2449. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Solter K. M., Gibor A. Evidence for role of flagella as sensory transducers in mating of Chlamydomonas reinhardi. Nature. 1977 Feb 3;265(5593):444–445. doi: 10.1038/265444a0. [DOI] [PubMed] [Google Scholar]
  24. Solter K. M., Gibor A. Removal and recovery of mating receptors on flagella of Chlamydomonas reinhardi. Exp Cell Res. 1978 Aug;115(1):175–181. doi: 10.1016/0014-4827(78)90414-7. [DOI] [PubMed] [Google Scholar]
  25. Tomson A. M., Demets R., Sigon C. A., Stegwee D., van den Ende H. Cellular Interactions during the Mating Process in Chlamydomonas eugametos. Plant Physiol. 1986 Jun;81(2):522–526. doi: 10.1104/pp.81.2.522. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Zacharius R. M., Zell T. E., Morrison J. H., Woodlock J. J. Glycoprotein staining following electrophoresis on acrylamide gels. Anal Biochem. 1969 Jul;30(1):148–152. doi: 10.1016/0003-2697(69)90383-2. [DOI] [PubMed] [Google Scholar]
  27. van den Ende H. Sexual agglutination in chlamydomonads. Adv Microb Physiol. 1985;26:89–123. doi: 10.1016/s0065-2911(08)60395-1. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of Cell Biology are provided here courtesy of The Rockefeller University Press

RESOURCES