Cell wall construction in Saccharomyces cerevisiae

Abstract

In this review, we discuss new insights in cell wall architecture and cell wall construction in the ascomycetous yeast Saccharomyces cerevisiae. Transcriptional profiling studies combined with biochemical work have provided ample evidence that the cell wall is a highly adaptable organelle. In particular, the protein population that is anchored to the stress-bearing polysaccharides of the cell wall, and forms the interface with the outside world, is highly diverse. This diversity is believed to play an important role in adaptation of the cell to environmental conditions, in growth mode and in survival. Cell wall construction is tightly controlled and strictly coordinated with progression of the cell cycle. This is reflected in the usage of specific cell wall proteins during consecutive phases of the cell cycle and in the recent discovery of a cell wall integrity checkpoint. When the cell is challenged with stress conditions that affect the cell wall, a specific transcriptional response is observed that includes the general stress response, the cell wall integrity pathway and the calcineurin pathway. This salvage mechanism includes increased expression of putative cell wall assemblases and some potential cross-linking cell wall proteins, and crucial changes in cell wall architecture. We discuss some more enzymes involved in cell wall construction and also potential inhibitors of these enzymes. Finally, we use both biochemical and genomic data to infer that the architectural principles used by S. cerevisiae to build its cell wall are also used by many other ascomycetous yeasts and also by some mycelial ascomycetous fungi.

Cell Wall β-(1,6)-Glucan of Saccharomyces cerevisiae

“…The function of the short ␤-(1,3)-glucan side chains is presently unknown, but they could be anchors for other cell wall components, such as glycosylphasphatidylinositol-anchored cell wall proteins, which are known to be linked to ␤-(1,6)-glucan (50, 51) or chitin side chains, especially when the cell is under stress (52,53). This result also confirms the role of this ␤-(1,6)-glucan as a flexible linker in the cell wall organization (Fig.…”

The indentation of pressurized elastic shells: from polymeric capsules to yeast cells

“…Although this flow could in principle be modelled [28], the relatively small size of indentations, together with the experimental observation that results are unchanged upon varying the indentation speed, suggest that the assumption made in our analysis of constant pressure difference during indentation is satisfactory. Other complications include the layered structure of the yeast cell wall, with not all layers contributing equally to its mechanical strength [29], and the potentially complicated constitutive law relating stresses and strains. Nevertheless, the application of the theoretical understanding developed from the idealized model presented in this paper gives us a starting point for extracting characteristic moduli and values for the internal osmotic pressure.…”

Cell wall structure of selected yeast species as a factor of magnesium binding ability

“…Glucose polymers present in yeast cell wall, that is, b-Dglucans, are organized in the form of a three-dimensional structure consisting of random coils, single helices and triple helices [20]. Between glucan side chains, hydrogen bonds are formed and they cause a coiling up of the molecule with helix formation.…”