Characterization of the purified Chlamydomonas minus agglutinin.

Collin‐Osdoby, Patricia; Adair, W S

doi:10.1083/jcb.101.3.1144

Cited by 38 publications

(20 citation statements)

References 16 publications

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“…Sexual recognition in C. reinhardtii is effected first by flagellar agglutination and then by fringe-fringe interactions at the plasma membrane (reviewed in . The genes encoding the flagellar agglutinins have not yet been cloned, but the proteins have been purified and characterized (Cooper et al, 1983;Collin-Osdoby and Adair, 1985) as hydroxyproline-rich glycoproteins with amino acid compositions very different from the fusl protein. Therefore, these two recognition systems clearly represent independent evolutionary ideas.…”

Section: The Fusl Gene Also Rescues the Impll Mutantmentioning

confidence: 99%

A sex recognition glycoprotein is encoded by the plus mating-type gene fus1 of Chlamydomonas reinhardtii.

Ferris

Woessner

Goodenough

1996

MBoC

121

108

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Sexual fusion between plus and minus gametes of the unicellular green alga Chlamydomonas reinhardtii entails adhesion between plus-specific and minus-specific "fringe" proteins displayed on the plasma membrane of gametic mating structures. We report the identification of the gene (fusl) encoding the plus fringe glycoprotein, which resides in a unique domain of the mating-type plus (mt+) locus, and which was identified by transposon insertions in three fusion-defective mutant strains. Transformation with fusl ± restores fringe and fusion competence to these mutants and to the pseudo-plus mutant impll mt-, defective in minus differentiation. The fusl gene is remarkable in lacking the codon bias found in all other nuclear genes of C. reinhardtii. INTRODUCTIONThe mating-type (mt) locus of the unicellular green alga Chlamydomonas reinhardtii controls gametic recognition and fusion, zygote development and meiosis, and the sexual transmission of organelle genomes . The locus, which resides in the left arm of linkage group VI, has been cloned recently (Ferris and Goodenough, 1994) and shown to be a large (-1 Mb) region under recombinational suppression and composed of three domains: a centromere-proximal (C) domain and a telomere-proximal (T) domain in which the mating-type plus (mt+) and mating-type minus (mt-) sequences are homologous, and a central rearranged (R) domain in which the mt+ and mt-sequences show inversions, deletions/insertions, and nonhomologous regions. An obvious inference from these data is that at least some of the nonhomologous regions contain genes coding for structural and regulatory proteins unique to either mt+ or mt-gametes.Sexual fusion between C. reinhardtii gametes entails the interaction of mt+ and mt-mating structures, organelles that assemble during gametic differentiation (Martin and Goodenough, 1975) and associate with

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Section: The Fusl Gene Also Rescues the Impll Mutantmentioning

confidence: 99%

A sex recognition glycoprotein is encoded by the plus mating-type gene fus1 of Chlamydomonas reinhardtii.

Ferris

Woessner

Goodenough

1996

MBoC

121

108

View full text Add to dashboard Cite

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“…In pioneering studies, Wiese documented that the mating-typespecific components that induce mating-type plus gametic flagella to adhere to mating-type minus gametic flagella could be recovered from the culture medium (Fö rster and Wiese, 1954;Wiese, 1965). Subsequent analyses of such gamone preparations revealed them to contain flagellar membrane vesicles (Bergman et al, 1975;Snell, 1976;Musgrave et al, 1981), and further studies eventually led to the purification and extensive characterization of their component agglutinin proteins in both C. reinhardtii and the distantly related C. eugametos Cooper et al, 1983;Collin-Osdoby et al, 1984;Adair, 1985;Collin-Osdoby and Adair, 1985;Samson et al, 1987;Homan et al, 1988;Goodenough and Adair, 1989).…”

Section: Introductionmentioning

confidence: 99%

PlusandMinusSexual Agglutinins fromChlamydomonas reinhardtii

et al. 2005

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Gametes of the unicellular green alga Chlamydomonas reinhardtii undergo sexual adhesion via enormous chimeric Hyp-rich glycoproteins (HRGPs), the plus and minus sexual agglutinins, that are displayed on their flagellar membrane surfaces. We have previously purified the agglutinins and analyzed their structural organization using electron microscopy. We report here the cloning and sequencing of the Sag1 and Sad1 genes that encode the two agglutinins and relate their derived amino acid sequences and predicted secondary structure to the morphology of the purified proteins. Both agglutinin proteins are organized into three distinct domains: a head, a shaft in a polyproline II configuration, and an N-terminal domain. The plus and minus heads are related in overall organization but poorly conserved in sequence except for two regions of predicted hydrophobic a-helix. The shafts contain numerous repeats of the PPSPX motif previously identified in Gp1, a cell wall HRGP. We propose that the head domains engage in autolectin associations with the distal termini of their own shafts and suggest ways that adhesion may involve head-head interactions, exolectin interactions between the heads and shafts of opposite type, and antiparallel shaft-shaft interactions mediated by carbohydrates displayed in polyproline II configurations.

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“…Several laboratories have been interested in the initial adhesive interaction. Recently Goodenough, Heuser, Adair, and co-workers identified high molecular mass glycoproteins rich in hydroxyproline that are involved in the adhesive interaction (1,2,4,9,10,16). Saito and Matsuda (35,37) obtained similar results using different purification methods, and van den Ende's laboratory has identified similar high molecular mass agglutinin molecules in C. eugametos (20,33,45).…”

mentioning

confidence: 99%

A monoclonal antibody that blocks adhesion of Chlamydomonas mt+ gametes.

Snell¹,

Clausell

Perillo³

et al. 1986

The Journal of Cell Biology

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Abstract. During the mating reaction (fertilization) in the biflagellated alga, Chlamydomonas reinhardtii, mt* and mt-gametes adhere to each other via their flagella and subsequently fuse to form quadriflagellated zygotes. In the studies reported here, we describe a monoclonal antibody directed against an mt + flagellar surface molecule. The antibody blocks the adhesiveness of mt + gametes, isolated mt ÷ flagella, and detergent extracts thereof. It has no effect on mt-gametes. Cyanogen bromide-activated Sepharose beads derivatized with the antibody bind only mt + gametes; mt-gametes and mt ÷ and mt-vegetative cells are unreactive with the derivatized beads. The interaction of mt + gametes with the beads is dynamic and cells continuously bind, detach, and rebind to the beads. Surprisingly, antibody-derivatized beads that have been incubated with mt + gametes acquire the ability to bind mr-gametes. Moreover, extraction of the preincubated beads with detergents releases active mt + adhesion molecules. The evidence suggests that binding of the antibody to the flagellar surface adhesion molecules causes their release from the flagellar surface, possibly mimicking the normal mechanism of flagellar de-adhesion.W HEN gametes of opposite mating types of the biflagellated alga Chlamydomonas reinhardtii are mixed together, they adhere to each other via their flagella and form large clumps of aggregating cells. Within these clumps, pairs of cells form that eventually fuse to become quadriflagellated zygotes. Several laboratories have been interested in the initial adhesive interaction. Recently Goodenough, Heuser, Adair, and co-workers identified high molecular mass glycoproteins rich in hydroxyproline that are involved in the adhesive interaction (1, 2, 4, 9, 10, 16). Saito and Matsuda (35, 37) obtained similar results using different purification methods, and van den Ende's laboratory has identified similar high molecular mass agglutinin molecules in C. eugametos (20,33, 45).Our laboratory has been interested in the molecular details of the adhesive interaction as well as a specific de-adhesion mechanism that we have characterized (39,(40)(41)(42)44). We showed that as cells adhere to each other they continuously inactivate the adhesiveness of each other's flagella (42, 44). Replacement of these lost adhesive sites requires protein synthesis (36, 37, 42) and protein glycosylation (29, 39, 48); Cooper et al. showed that hydroxylation of proline was also required for replacement of these lost adhesion sites (10). Similar results have been shown for Chlamydomonas eugametos (32,33, 45,(47)(48)(49). To more fully study this adhesion-induced loss of flagellar adhesion sites and to identify molecules responsible for adhesion we have begun to use an immunological approach. In earlier unpublished studies we had attempted to prepare rabbit polyclonal antibodies against flagella or flagellar surface fractions that would specifically block adhesiveness of mating type plus (mr+) 1 or mating type minus (mr-) gametes. To date, all of th...

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Characterization of the purified Chlamydomonas minus agglutinin.

Cited by 38 publications

References 16 publications

A sex recognition glycoprotein is encoded by the plus mating-type gene fus1 of Chlamydomonas reinhardtii.

A sex recognition glycoprotein is encoded by the plus mating-type gene fus1 of Chlamydomonas reinhardtii.

PlusandMinusSexual Agglutinins fromChlamydomonas reinhardtii

A monoclonal antibody that blocks adhesion of Chlamydomonas mt+ gametes.

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