Saccharomyces cerevisiae cell wall proteins

Cell wall of Saccharomyces cerevisiae contains more than 20 different manno proteins. They are considered to play different roles in building, maintain ing and modifying the wall itself when different cell cycle events, or othe r conditions, require so. Besides, they are important for interactions of c ells with their surrounding, the example of which are intercellular interac tions during agglutination or flocculation. Cell wall proteins can be divid ed in three groups according to the mechanism by which they are attached to the wall. Some proteins are connected to wall structural polysaccharides n oncovalently and the identification of several members of this group showed that they most probably all possess enzymatic activities. The second group comprises proteins covalently attached, most probably to beta-16-glucan,an d they can be released from the wall by different glucanase preparations. F inally, a group of proteins can be extracted from the wall by 30 mM NaOH bu t the actual link by which they are attached to the cell wall is unknown. In this paper a survey of so far identified and partially characterised cel l wall proteins of each of the three groups is presented. Besides, the pres ent knowledge of how the proteins get incorporated into the wall as well as their structure and potential role is summarised.