Biogenesis, localization and function of model fungal
adhesins.
Mingliang Zhang, Guohong Huang, Daniel Bennett,
Scott E. Erdman
Department of Biology, Syracuse University,
130 College Place, Syracuse, NY 13244-1220, USA
We have investigated
the biogenesis, localization and function of different adhesin proteins
that act during yeast mating. In response to mating pathway signaling,
transcription of the genes encoding the GPI-anchored proteins Aga1p,
Sag1p and Fig2p are markedly induced. The agglutinins Aga1p, Aga2p and
Sag1p are glycoproteins that function in the specific adherence of cells
of opposite mating types during conjugation, while presence of the
adhesin Fig2p modulates agglutinin function. Fig2p is also required for
normal mating cell morphogenesis under conditions involving cell-cell
contact. We have found a novel role for the adhesin Fig2p in maintaining
the integrity of cells responding to both mating pheromone-generated
signals and to other cells in mating mixtures. Consistent with a role of
Fig2p in cell wall organization, fig2 mutants show increased activation
of the Rho1/Pkc1 cell integrity pathway relative to wild type cells. We
have also begun to further examine the nature and functional
significance of specific posttranslational modifications that occur to
the different adhesins during their biogenesis, including GPI-anchor
addition/glucan attachment and O-linked glycosylation. Progress on these
studies will also be presented.
Return to YGM 2002 Home at SGD