Identification of a putative alpha-glucan synthase essential for cell wall construction and morphogenesis in fission yeast
Identification of a putative alpha-glucan synthase essential for cell wall construction and morphogenesis in fission yeast
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DOI：
10.1073/pnas.95.16.9161
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发表时间：
1998-08-04
影响因子：
11.1
通讯作者：
Klausner, RD
中科院分区：
文献类型：
--
作者：
Hochstenbach, F;Klis, FM;Klausner, RD
细胞壁保护真菌免遭裂解并决定其细胞形状。 α-葡聚糖是真菌细胞壁的主要碳水化合物成分，但其功能未知，其合酶仍然难以捉摸。在这里，我们描述了裂殖酵母基因 ags1(+)，它编码假定的 α-葡聚糖合酶。与其他碳水化合物聚合物合酶的结构相比，预测的 Ags1 蛋白由两个可能的催化结构域组成 用于α-葡聚糖组装，即用于α-葡聚糖合成的细胞内结构域和推测用于交联或重塑α-葡聚糖的细胞外结构域。此外，预测的 Ags1 蛋白含有多次跨膜结构域，可能有助于 α-葡聚糖跨膜转运。温度敏感突变体中 Ags1p 功能的丧失会导致细胞裂解，而在半允许温度下生长的突变体细胞的细胞壁 α-葡聚糖水平降低，并且无法维持杆状形状，导致细胞变圆。这些发现表明 α-葡聚糖对于裂殖酵母形态发生至关重要。
The cell wall protects fungi against lysis and determines their cell shape. Alpha-glucan is a major carbohydrate component of the fungal cell wall, but its function is unknown and its synthase has remained elusive, Here, we describe a fission yeast gene, ags1(+), which encodes a putative alpha-glucan synthase, In contrast to the structure of other carbohydrate polymer synthases, the predicted Ags1 protein consists of two probable catalytic domains for alpha-glucan assembly, namely an intracellular domain for alpha-glucan synthesis and an extracellular domain speculated to cross-link or remodel alpha-glucan. In addition, the predicted Ags1 protein contains a multipass transmembrane domain that might contribute to transport of alpha-glucan across the membrane. Loss of Ags1p function in a temperature-sensitive mutant results in cell lysis, whereas mutant cells grown at the semipermissive temperature contain decreased levels of cell wall alpha-glucan and fail to maintain rod shapes, causing rounding of the cells, These findings demonstrate that alpha-glucan is essential for fission yeast morphogenesis.