Mating type-specific cell-cell recognition of Saccharomyces cerevisiae: cell wall attachment and active sites of a- and alpha-agglutinin

EMBO J. 1994 Oct 17;13(20):4737-44.

Abstract

Mating type-specific agglutination of Saccharomyces cerevisiae a and alpha cells depends on the heterophilic interaction of two cell surface glycoproteins, the gene products of AG alpha 1 and AGA2. Evidence is presented with immunogold labelling that the alpha-agglutinin is part of the outer fimbrial cell wall coat. The a-agglutinin is bound via two S-S bridges (Cys7 and Cys50) to a cell wall component, most probably the gene product of AGA1. His273 of alpha-agglutinin has previously been shown to be essential for a- and alpha-agglutinin interaction and a model based on two opposing ion-pairs had been proposed. By site-directed mutagenesis this possibility has now been excluded. With the help of various peptides, either chemically synthesized, obtained by proteolysis of intact glycosylated a-agglutinin or prepared from a fusion protein expressed in Escherichia coli, the biologically active region of a-agglutinin was located at the C-terminus of the molecule. A peptide consisting of the C-terminal 10 amino acids (GSPIN-TQYVF) was active in nanomolar concentrations. Saccharide moieties, therefore, are not essential for the mating type-specific cell-cell interaction; glycosylated peptides are, however, four to five times more active than non-glycosylated ones. Comparisons of the recognition sequences of the S. cerevisiae agglutinins with that of the Dictyostelium contact site A glycoprotein (gp80), as well as with those of the various families of cell adhesion molecules of higher eucaryotes, have been made and are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agglutinins / genetics
  • Agglutinins / metabolism
  • Agglutinins / physiology*
  • Amino Acid Sequence
  • Base Sequence
  • Binding Sites
  • Cell Adhesion / physiology*
  • Cell Adhesion Molecules
  • Cell Wall / metabolism*
  • Fungal Proteins / physiology
  • Mating Factor
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Peptides / physiology
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / physiology*
  • Saccharomyces cerevisiae Proteins*

Substances

  • AGA1 protein, S cerevisiae
  • AGA2 protein, S cerevisiae
  • Agglutinins
  • Cell Adhesion Molecules
  • Fungal Proteins
  • Peptides
  • Saccharomyces cerevisiae Proteins
  • a-agglutinin protein, S cerevisiae
  • Mating Factor