Characterization of chlamydomonas sexual agglutinins
Open Access
- 1 January 1985
- journal article
- Published by The Company of Biologists in Journal of Cell Science
- Vol. 1985 (Supplement), 233-260
- https://doi.org/10.1242/jcs.1985.supplement_2.13
Abstract
Molecules (agglutinins) mediating mating-type-specific adhesion of Chlamydomonas reinhardtii plus and minus gametes have been purified and shown to be homologous by several criteria. Both are large, extrinsic glycoproteins, rich in hydroxyproline and serine, which display similar sensitivities to a variety of inactivating agents. Direct visualization of agglutinins by the rapid-freeze deep-etch technique of Heuser reveals that both are extremely asymmetric, fibrous molecules with similar but distinct topographies. Each has a globular head, a rigid domain, a relatively flexible region and a terminal hook. In situ images show that the molecules associate with the flagellar surface via the latter (hook) domain, projecting the globular head distally. A functional role for the head is implied from inactivation studies (thermolysin digestion and reduction/alkylation) showing a selective modification of this domain. A library of monoclonal antibodies, raised against the plus agglutinin, has been used to probe the structural organization of this molecule by immunotopographic mapping. Two distinct classes of monoclonal antibodies are shown to react with carbohydrate epitopes localized to the two termini (head and hook) of the plus agglutinin while a third recognizes a polypeptide determinant that repeats along the rod-like portion of the molecule. The latter class is gamete (but not mating-type)-specific while the other two classes display distinct patterns of cross reactivity. Finally, the Chlamydomonas agglutinins show a striking compositional and structural resemblance to the major cell wall glycoproteins of this organism. Wall glycoproteins, which are also rich in hydroxyproline and serine and capable of self-assembly, may therefore share a common evolutionary heritage with the agglutinins.Keywords
This publication has 42 references indexed in Scilit:
- Structure of the Chlamydomonas agglutinin and related flagellar surface proteins in vitro and in situ.The Journal of cell biology, 1985
- Characterization of the purified Chlamydomonas minus agglutinin.The Journal of cell biology, 1985
- Cell-Cell Interactions in ChlamydomonasAnnual Review of Plant Physiology, 1985
- Chlamydomonas agglutinin conjugated to agarose beads as an in vitro probe of adhesionExperimental Cell Research, 1984
- Activation for cell fusion in Chlamydomonas: analysis of wild-type gametes and nonfusing mutants.The Journal of cell biology, 1982
- Experimental dissection of flagellar surface motility in chlamydomonasThe Journal of cell biology, 1980
- Aggregation-dependent turnover of flagellar adhesion molecules in chlamydomonas gametesThe Journal of cell biology, 1980
- Tipping and mating-structure activation induced in Chlamydomonas gametes by flagellar membrane antisera.The Journal of cell biology, 1978
- Mating in Chlamydomonas: a system for the study of specific cell adhesion. I. Ultrastructural and electrophoretic analyses of flagellar surface components involved in adhesion.The Journal of cell biology, 1976
- Self-assembly of a plant cell wall in vitroJournal of Molecular Biology, 1975