title: Cell-cell recognition in yeast. Characterization of the sexual agglutination factors from Saccharomyces kluyveri.
abstract: The cell surface molecules responsible for sexual agglutination between haploid cells of opposite mating type from Saccharomyces kluyveri have been purified and characterized. The 17-factor, released from 17-cells by beta-glucanase digestion (Zymolyase), is a glycoprotein of 6 X 10(4) Da. Its binding activity is heat- and protease-labile, but it is stable to reducing agents and exo-alpha-mannosidase digestion. The 16-factor, released from 16-cells by Zymolyase digestion, has a molecular weight of 5 X 10(5) and is over 95% carbohydrate. An active binding fragment can be released from 16-factor, from the factor purified from a mutant of 16-cells (16(mnn1)-factor), and from the surfaces of the cells themselves by dithiothreitol treatment. The 16(mnn1)-binding fragment has a molecular weight of 2 X 10(4) and is 30% carbohydrate. Its binding activity is stable to heat and some proteases, but it is labile to pronase, carboxypeptidases A and Y, alpha-mannosidases, and mild periodate treatment. 125I-16(mnn1)-binding fragment adheres specifically to 17-cells but does not bind to 16-cells or cells of other yeast strains. The binding of the labeled fragment to 17-cells is characterized by a KA of 10(8) M-1, and 5 X 10(5) binding sites are present per cell. The purified intact factors are monovalent and appear to interact in a lock and key fashion to cause the specific agglutination of S. kluyveri 16- and 17-cells.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002450:Cell Communication; D006238:Haploidy; D007700:Kinetics; D000072235:Mating Factor; D008970:Molecular Weight; D010447:Peptide Hydrolases; D010455:Peptides / Q000302:isolation & purification*; D012440:Saccharomyces / Q000502:physiology*; D013045:Species Specificity
chemical_list: D000596:Amino Acids; D010455:Peptides; D000072235:Mating Factor; D010447:Peptide Hydrolases