ISSN:
1432-2145
Keywords:
Chlamydomonas
;
Agglutination
;
Membrane anchor
;
Glycoprotein
;
Flagella
;
Receptor
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The protein composition of the flagellar membrane of C. eugametos mt −gametes was analyzed using SDS-polyacrylamide gel electrophoresis. The association of the proteins with the membrane was assessed by differential extraction and an assay for glycosylation. Particular attention was paid to integral membrane proteins that could be associated with the mt − agglutinin, the membrane-bound sexual receptor by which the mt − gamete binds to its mt + partner. This agglutinin is a peripheral membrane glycoprotein and must be bound to the flagellar surface by an integral membrane anchor protein that connects the agglutinin with the cell's interior. Immunoaffinity chromatography was performed using Mab 66.3, a monoclonal antibody specific for the mt − agglutinin, in order to isolate protein complexes consisting of agglutinin molecules and associated components. Only one integral membrane glycoprotein (Mr = 125 kDa) was isolated that has an association with the agglutinin. It did not bind Mab 66.3, but did bind the lectin wheat germ agglutinin. This was an expected property of the membrane anchor protein because previous research (Kooijman et al. 1989) has shown that cross-linking a WGA-binding glycoprotein by this lectin induces sexual responses that are similar to those induced by agglutinin-agglutinin interactions during mating. We conclude that the 125-kDa glycoprotein is the membrane anchor for the agglutinin.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00198850
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