Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai 201306, China.
Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai 201306, China; Class 1, 2016 Biological Science, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
Int J Biol Macromol. 2019 Aug 15;135:745-751. doi: 10.1016/j.ijbiomac.2019.05.205. Epub 2019 May 29.
Shell biomineralization is a process where inorganic minerals accumulate upon a chitinous scaffold under the control of multifunctional matrix proteins. In this study, we cloned a novel matrix protein gene from the mantle of Hyriopsis cumingii. The predicted protein, hichin, contains a chitin-binding domain and exhibited the highest expressional level in mantle tissue, with positive signals mainly detected in dorsal epithelial cells of the pallial mantle according to in situ hybridization, indicating its possible involvement in shell nacreous layer biomineralization. RNA interference showed that hichin suppression induced disordered self-assembly of the insoluble framework in the nacreous layer, and that the newly formed calcium carbonate crystals could not bind to organic frameworks. Furthermore, hichin was primarily responsible for building the framework during initial nacre deposition in pearl formation. Moreover, the chitin-binding domain of hichin also provided crystal morphology regulation in vitro crystallization assay. These results indicated that hichin is involved in the self-assembly of organic frameworks and morphological regulation in shell nacreous layer.
贝壳生物矿化是一个在多功能基质蛋白的控制下，无机矿物质在几丁质支架上积累的过程。在这项研究中，我们从中国蛤蜊的套膜中克隆了一个新的基质蛋白基因。预测的蛋白 hichin 含有一个几丁质结合结构域，在套膜组织中表达水平最高，原位杂交的阳性信号主要检测到套膜的背侧上皮细胞，表明其可能参与了贝壳珍珠层的生物矿化。RNA 干扰表明，hichin 的抑制导致珍珠层中不溶性框架的无序自组装，并且新形成的碳酸钙晶体不能与有机框架结合。此外，hichin 在珍珠形成过程中最初的珍珠层沉积中主要负责构建框架。此外，hichin 的几丁质结合结构域在体外结晶实验中也提供了晶体形态调控。这些结果表明 hichin 参与了有机框架的自组装和贝壳珍珠层的形态调控。
