Institute of Marine Biotechnology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang Province, 314006, China.
Sci Rep. 2018 Feb 23;8(1):3563. doi: 10.1038/s41598-018-21797-w.
Kinase-family with sequence similarity 20, member C (Fam20C) is a protein kinase, which can phosphorylate biomineralization related proteins in vertebrate animals. However, the function of Fam20C in invertebrate animals especially the role in biomineralization is still unknown. Herein, we cloned the cDNA of fam20C from the pearl oyster, Pinctada fucata. It is showed that the expression of fam20C in the mantle edge was much higher than other tissues. In situ hybridization showed that fam20C was expressed mostly in the outer epithelial cells of the middle fold, indicating it may play important roles in the shell formation. Besides, fam20C expression increased greatly in the D-shape stage of pearl oyster development, when the shell was first formed. During the shell repair process, the expression level of fam20C increased 1.5 times at 6 h after shell notching. Knockdown of fam20C in vivo by RNA interference resulted in abnormally stacking of calcium carbonate crystals at the edges of nacre tablets, showing direct evidence that fam20C participates in the shell formation. This study provides an insight into the role of kinase protein in the shell formation in mollusk and broaden our understanding of biomineralization mechanism.
激酶家族成员 20，C 型（Fam20C）是一种蛋白激酶，可磷酸化脊椎动物生物矿化相关蛋白。然而，Fam20C 在无脊椎动物中的功能，特别是在生物矿化中的作用尚不清楚。本研究从珍珠贝（Pinctada fucata）克隆了 fam20C 的 cDNA。结果表明，fam20C 在边缘膜中的表达明显高于其他组织。原位杂交显示 fam20C 主要在外褶的外分泌细胞中表达，表明其可能在贝壳形成中发挥重要作用。此外，fam20C 在珍珠贝发育的 D 形阶段（贝壳首次形成时）的表达量大大增加。贝壳缺口 6 小时后，贝壳修复过程中 fam20C 的表达水平增加了 1.5 倍。体内 RNA 干扰敲低 fam20C 导致珍珠层片边缘的碳酸钙晶体异常堆积，这直接证明了 fam20C 参与了贝壳的形成。本研究深入了解了蛋白激酶在软体动物贝壳形成中的作用，拓宽了我们对生物矿化机制的认识。
