Identification of a 49-kDa hydrophobic cell wall mannoprotein present in velum yeast which may be implicated in velum formation

Abstract

Analysis of velum-forming yeast cell wall components released by L-1,3-glucanase treatment were compared with those of a non velumforming yeast. SDS^PAGE electrophoresis and Western blotting with ConA-peroxidase staining of mannoproteins allowed us to identify a 49-kDa mannoprotein present in the cell wall of the velum-forming yeast and hardly visible in the control. The cell wall nature of this protein was confirmed by labelling with the non-permeable sulfosuccinimydiyl-6-(biotinamido)hexanoate reagent. A partial purification of this mannoprotein by anion exchange HPLC followed by surface hydrophobicity determination revealed that the fraction containing the 49-kDa mannoprotein was the most hydrophobic. Since cell surface hydrophobicity plays an important role in aggregate formation, it is likely that this mannoprotein is involved in velum formation. ß

Differential Flo8p‐dependent regulation of FLO1 and FLO11 for cell–cell and cell–substrate adherence of S. cerevisiae S288c

“…Another example for the importance of genomic rearrangements for the adaptation of the yeast cell–surface is the foam forming AWA1 gene product. This protein is present in S. cerevisiae strains used for sake production, and is presumably a chimeric protein corresponding to parts of two genes of the commonly used S288c (Alexandre et al ., 2000; Shimoi et al ., 2002). Accordingly S288c is unable to form foams or biofilms, even after the restauration of FLO8 (Fig.…”

Choosing the right lifestyle: adhesion and development inSaccharomyces cerevisiae

“…This indicates that efficient flor formation might depend on factors other than hydrophobicity, which might be provided by Flo11, but not by other flocculins. Other nonflocculin proteins have also been described that confer cell surface hydrophobicity and are involved in velum formation in French wine yeast (Alexandre et al ., 2000) and foam formation in sake‐producing yeast (Shimoi et al ., 2002). In addition, the formation of flors might be further stabilized by an extracellular matrix (ECM) of unknown composition that has been observed in certain yeast strains (Kuthan et al ., 2003; Zara et al ., 2009).…”

Sed1p and Srl1p are required to compensate for cell wall instability in Saccharomyces cerevisiae mutants defective in multiple GPI‐anchored mannoproteins

“…GPI‐Ccwps are involved in a number of phenomena including sexual agglutination (Lipke and Kurjan, 1992; Cappellaro et al. , 1994), cell surface hydrophobicity (Alexandre et al ., 2000), flocculation (Teunissen et al ., 1993) and resistance towards lytic enzymes in stationary phase cells (Shimoi et al ., 1998). With the exception of the agglutinins, the functions or enzymatic activities of covalently linked cell wall proteins remain mostly obscure.…”