Characterization of a 200-kDa diatom protein that is specifically associated with a silica-based substructure of the cell wall
Characterization of a 200-kDa diatom protein that is specifically associated with a silica-based substructure of the cell wall
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DOI：
10.1111/j.1432-1033.1997.00099.x
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发表时间：
1997-11-15
期刊：
影响因子：
--
通讯作者：
Sumper, M
中科院分区：
文献类型：
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作者：
Kroger, N;Lehmann, G;Sumper, M
硅藻的细胞壁由硅基支架和有机大分子组成。据信位于细胞壁中的蛋白质控制支架物种特异性二氧化硅结构的形态发生。然而，硅藻细胞壁内不同的二氧化硅元素和特定蛋白质的相关数据尚未报道。在这里，细胞壁蛋白质HEP 2 OO（200-kDa的HE-可提取的蛋白质）从硅藻梭形刺囊藻进行鉴定和表征。HEP 200与二氧化硅支架的子结构紧密相关。它是一个新的蛋白质家族的成员，其中两个成员被确定。每个成员都显示相同的二分结构。N-末端部分由可变数量的重复序列基序（PSCD结构域）组成，而C-末端部分是独特的。免疫定位实验揭示了细胞壁内不同蛋白质的排列。Frustulins，一组先前描述的糖蛋白，构成细胞壁的外涂层，并表现出普遍存在的分布。相比之下，HEP 200特异性地位于完整细胞壁中约6个二氧化硅条带的子集处，由截头壳蛋白屏蔽。因此，这项研究确定了硅藻细胞壁蛋白（HEP 200），这是与一个独特的硅支架的子结构。
The cell wall of a diatom is made up of a silica-based scaffold and organic macromolecules. Proteins located in the cell wall are believed to control morphogenesis of the species-specific silica structures of the scaffold. However, data that correlate distinct silica elements and specific proteins within the diatom cell wall have not been reported. Here, the cell wall protein HEP2OO (200-kDa HE-extractable protein) from the diatom Cylindrotheca fusiformis is identified and characterized. HEP200 is tightly associated with a substructure of the silica scaffold. It is a member of a new protein family, of which two more members are identified. Each member displays the same bipartite structure. The N-terminal part consists of a variable number of a repeated sequence motif (PSCD domain), whereas the C-terminal part is unique, Immunolocalization experiments revealed the arrangement of different proteins within the cell wall. Frustulins, a previously described group of glycoproteins, constitute the outer coat of the cell wall and exhibit a ubiquitous distribution. In contrast, HEP200 is specifically located at a subset of about six silica strips in intact cell walls, shielded by frustulins. This study therefore identifies a diatom cell wall protein (HEP200) that is associated with a distinct substructure of the silica scaffold.