Title: | The AGA1 product is involved in cell surface attachment of the Saccharomyces cerevisiae cell adhesion glycoprotein a-agglutinin |
Author(s): | Roy A; Lu CF; Marykwas DL; Lipke PN; Kurjan J; |
Address: | "Department of Biological Sciences, Columbia University, New York, New York 10027" |
DOI: | 10.1128/mcb.11.8.4196-4206.1991 |
ISSN/ISBN: | 0270-7306 (Print) 1098-5549 (Electronic) 0270-7306 (Linking) |
Abstract: | "Saccharomyces cerevisiae a and alpha cells express the complementary cell surface glycoproteins a-agglutinin and alpha-agglutinin, respectively, which interact with one another to promote cellular aggregation during mating. Treatment of S. cerevisiae a cells with reducing agents releases the binding subunit of a-agglutinin, which has been purified and characterized; little biochemical information on the overall structure of a-agglutinin is available. To characterise a-agglutinin structure and function, we have used a genetic approach to clone an a-agglutinin structural gene (AGAI). Mutants with a-specific agglutination defects were isolated, the majority of which fell into a single complementation group, called aga1. The aga1 mutants showed wild-type pheromone production and response, efficient mating on solid medium, and a mating defect in liquid medium; these phenotypes are characteristic of agglutinin mutants. The AGA1 gene was cloned by complementation; the gene sequence indicated that it could encode a protein of 725 amino acids with high serine and threonine content, a putative N-terminal signal sequence, and a C-terminal hydrophobic sequence similar to signals for the attachment to glycosyl phosphatidylinositol anchors. Active a-agglutinin binding subunit is secreted by aga1 mutants, indicating that AGA1 is involved in cells surface attachment of a-agglutinin. This result suggests that AGA1 encodes a protein with functional similarity to the core subunits of a-agglutinin analogs from other budding yeasts. Unexpectedly, the AGA1 transcript was expressed and induced by pheromone in both a and alpha cells, suggesting that the a-specific expression of active a-agglutinin results only from a-specific regulation of the a-agglutinin binding subunit" |
Keywords: | "Agglutination Amino Acid Sequence Base Sequence Cell Adhesion Molecules Cell Membrane/physiology Crosses, Genetic DNA, Fungal/genetics/isolation & purification Escherichia coli/genetics Fungal Proteins/*genetics Genes, Dominant *Genes, Fungal Genetic Comp;" |
Notes: | "MedlineRoy, A Lu, C F Marykwas, D L Lipke, P N Kurjan, J eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Research Support, U.S. Gov't, P.H.S. 1991/08/01 Mol Cell Biol. 1991 Aug; 11(8):4196-206. doi: 10.1128/mcb.11.8.4196-4206.1991" |