Kapteyn J C, Van Den Ende H, Klis F M
Institute for Molecular Cell Biology, University of Amsterdam, BioCentrum Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands.
Biochim Biophys Acta. 1999 Jan 6;1426(2):373-83. doi: 10.1016/s0304-4165(98)00137-8.
Our knowledge of the yeast cell wall has increased rapidly in the past few years, allowing for the first time a description of its structure in molecular terms. Two types of cell wall proteins (CWPs) have been identified that are covalently linked to beta-glucan, namely GPI-CWPs and Pir-CWPs. Both define a characteristic supramolecular complex or structural unit. The GPI building block has the core structure GPI-CWP-->beta1,6-glucan-->beta1,3-glucan, which may become extended with one or more chitin chains. The Pir building block is less well characterized, but preliminary evidence points to the structure, Pir-CWP-->beta1,3-glucan, which probably also may become extended with one or more chitin chains. The molecular architecture of the cell wall is not fixed. The cell can make considerable adjustments to the composition and structure of its wall, for example, during the cell cycle or in response to environmental conditions such as nutrient and oxygen availability, temperature, and pH. When the cell wall is defective, dramatic changes can occur in its molecular architecture, pointing to the existence of cell wall repair mechanisms that compensate for cell damage. Finally, evidence is emerging that at least to a considerable extent the cell wall of Saccharomyces cerevisiae is representative for the cell wall of the Ascomycetes.
在过去几年中，我们对酵母细胞壁的了解迅速增加，首次能够从分子层面描述其结构。已鉴定出两种与β-葡聚糖共价连接的细胞壁蛋白（CWP），即GPI-CWP和Pir-CWP。两者都定义了一种特征性的超分子复合物或结构单元。GPI构建块具有核心结构GPI-CWP→β1,6-葡聚糖→β1,3-葡聚糖，其可能会延伸出一条或多条几丁质链。Pir构建块的特征尚不明确，但初步证据表明其结构为Pir-CWP→β1,3-葡聚糖，其可能也会延伸出一条或多条几丁质链。细胞壁的分子结构并非固定不变。细胞可以对其细胞壁的组成和结构进行相当大的调整，例如在细胞周期中，或响应营养物质和氧气供应、温度及pH值等环境条件时。当细胞壁存在缺陷时，其分子结构会发生显著变化，这表明存在能够补偿细胞损伤的细胞壁修复机制。最后，越来越多的证据表明，酿酒酵母的细胞壁至少在很大程度上代表了子囊菌的细胞壁。
