Silica transport in the demosponge Suberites domuncula:: fluorescence emission analysis using the PDMPO probe and cloning of a potential transporter
Silica transport in the demosponge Suberites domuncula:: fluorescence emission analysis using the PDMPO probe and cloning of a potential transporter
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DOI：
10.1042/bj20040463
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发表时间：
2004-08-01
影响因子：
4.1
通讯作者：
Müller, WEG
中科院分区：
文献类型：
--
作者：
Schröder, HC;Perovic-Ottstadt, S;Müller, WEG
硅是除氧之外地球上最丰富的元素。只有两个分类群使用这种元素作为其骨架的主要成分，即海绵（多孔动物门）和单细胞硅藻。细胞生物学和分子生物学技术相结合的结果表明，在demosponge Suberites domuncula，油酸是由转运。用荧光二氧化硅示踪剂PDMPO [2-（4-吡啶基）-5-{[4-（2-二甲基氨基乙基氨基甲酰基）甲氧基]苯基}-恶唑]孵育细胞显示出通过荧光的增加对异硫氰酸的响应;该过程是温度依赖性的，并且可以被DIDS（4，4-二异硫氰酸基芪-2，2-二磺酸）阻断。推定的NBC（Na+/HCO 3-）转运蛋白进行了鉴定，克隆和分析。推导出的蛋白质包括这些分子的所有特征，系统发育分析也将其归类为NBC转运蛋白家族。该cDNA被用于证明，在用谷氨酸处理细胞后，该基因的表达被强烈上调。原位杂交表明，海绵转运蛋白的表达发生在那些位于骨针（动物的骨骼元素）附近的细胞或骨针形成发生的区域。我们得出结论，这种转运蛋白参与二氧化硅的摄取，因此将其称为NBCSA {Na+/HCO 3-[Si（OH）（4）]}协同转运蛋白。
Silicon is, besides oxygen, the most abundant element on earth. Only two taxa use this element as a major constituent of their skeleton, namely sponges (phylum Porifera) and unicellular diatoms. Results from combined cytobiological and molecular-biological techniques suggest that, in the demosponge Suberites domuncula, silicic acid is taken up by a transporter. Incubation of cells with the fluorescent silica tracer PDMPO [2-(4-pyridyl)-5-{[4-(2-dimethylaminoethylaminocarbamoyl)methoxy]phenyl}-oxazole] showed a response to silicic acid by an increase in fluorescence; this process is temperature-dependent and can be blocked by DIDS (4,4-di-isothiocyanatostilbene-2,2-disulphonic acid). The putative NBC (Na+/HCO3-) transporter was identified, cloned and analysed. The deduced protein comprises all signatures characteristic of those molecules, and phylogenetic analysis also classifies it to the NBC transporter family. This cDNA was used to demonstrate that the expression of the gene is strongly up-regulated after treatment of cells with silicic acid. In situ hybridization demonstrated that the expression of the sponge transporter occurs in those cells that are located adjacent to the spicules (the skeletal element of the animal) or in areas in which spicule formation occurs. We conclude that this transporter is involved in silica uptake and have therefore termed it the NBCSA {Na+/HCO3-[Si(OH)(4)]} co-transporter.