Wall Replication in Saccharomyces Species: Use of Fluorescein-conjugated Concanavalin A to Reveal the Site of Mannan Insertion

Abstract

S U M M A R YThe wall mannan in dividing Saccharomyces cells was labelled by exposing the yeasts to fluorescein-conjugated concanavalin A. The yeasts were then allowed to grow in the absence of excess staining reagent and were examined by fluorescence microscopy at several intervals after the re-initiation of growth. The newly synthesized mannan was non-fluorescent and, thus, could be easily distinguished from the material present at the outset. Most new mannan was deposited in the wall surrounding the bud, and little if any of the mannan in the bud wall was derived from the surface of the mother cell. Deposition of new mannan in the mother cell was detected only in the bud scar. The distal tip of the growing bud was identified as the major site at which new mannan was inserted into the existing wall fabric. This area is also known to be the deposition site of newly synthesized glucan. Thus, with respect to these two major wall polysaccharides, wall replication in Saccharomyces cells resembles the apical mode exhibited by filamentous fungi.

Agglutination of Blastospores of Candida albicans by Concanavalin A and its Relationship with the Distribution of Mannan Polymers and the Ultrastructure of the Cell Wall

“…In agreement with Tkacz et al (1971), we have also shown that wall mannan components are the receptors for Con A binding and the subsequent agglutination. In animal cells, there is a substantial body of evidence that a 'clustering' of Con A receptors is one of the prerequisites for cells to agglutinate (Nicolson, 1974).…”

“…In keeping with these considerations, and in accord with the fluorescein-conjugated Con A binding studies of Tkacz et al (1971), we found that another strain of C. albicans ( A ,~) and also Saccharomyces cerevisiae, known to have a-mannan exposed on its surface (Bacon et al, 1969;Phaff, 1971), were agglutinated by Con A whereas a Rhodotorula glutinis strain, known not to contain a-mannan, was not agglutinated.…”

“…This protein specifically reacts with several polysaccharides, mainly of the U-D configuration, the extent of binding depending on the degree of saccharide branching (Goldstein, Hollerman & Merrick, 1965). So & Goldstein (1968) showed that yeast mannans are among the polysaccharides most tenaciously bound by Con A, and Tkacz and co-workers used fluorescein-conjugated Con A to stain specifically yeast mannan (Tkacz, Cybulska & Lampen, 1971) and to detect the sites of new mannan insertion during cell wall growth in Saccharomyces cerevisiae (Tkacz & Lampen, 1972).…”

Sec3p is involved in secretion and morphogenesis in Saccharomyces cerevisiae.

“…Budding can therefore be seen as a process of polarized secretion. Studies on the incorporation of cell wall components such as cell wall-bound acid phosphatase , mannan (Farkas et al, 1974), and glucan (Tkacz and Lampen, 1972) have shown that during most of the budding process, secretion is directed to the tip of the growing bud. When the daughter cell is about two-thirds the size of the mother cell, secretion becomes isotropic over the en-* Corresponding author.…”

Antimicrobial activity of lectins from Antimicrobial Activity of Lectins from Plants

“…The report of lecin interaction to fungal, such as fluorescein-conjugated wheat germ agglutinin has been shown to be an effective probe to detect chitin on hypha surfaces. (Barkai and Sharon, 1978;Galun et al, 1976;Galun et al, 1981;Mirelman et al, 1975;Molano et al, 1980;Tkacz and Lampson, 1972;Tracz et al, 1971;Tropchin et al, 1981). In 1975 Mirelman et al was found wheat germ agglutinin (WGA) can be inhibits spore germination and hyphal growth of Trichoderma viride and interferes with the synthesis of chitin (Mirelman et al, 1975).…”