Protein Science Laboratory of the Ministry of Education, School of Life Sciences, 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 Aug 16;8(1):12258. doi: 10.1038/s41598-018-29743-6.
Shell matrix proteins (SMPs) have important functions in biomineralization. In the past decades, the roles of SMPs were gradually revealed. In 2015, our group identified 72 unique SMPs in Pinctada fucata, among which Alveoline-like (Alv) protein was reported to have homologous genes in Pinctada maxima and Pinctada margaritifera. In this study, the full-length cDNA sequence of Alv and the functional analysis of Alv protein during shell formation were explored. The deduced protein (Alv), which has a molecular mass of 24.9 kDa and an isoelectric point of 11.34, was characterized, and the functional analyses was explored in vivo and in vitro. The Alv gene has high expression in mantle and could response to notching damage. The functional inhibition of Alv protein in vivo by injecting recombinant Alv (rAlv) antibodies destroyed prism structure but accelerated nacre growth. Western blot and immunofluorescence staining showed that native Alv exists in the EDTA-insoluble matrix of both prismatic and nacreous layers and has different distribution patterns in the inner or outer prismatic layer. Taken together, the characterization and functional analyses of matrix protein Alv could expand our understanding of basic matrix proteins and their functions during shell formation.
壳基质蛋白（SMPs）在生物矿化中具有重要功能。在过去的几十年中，SMPs 的作用逐渐被揭示。2015 年，我们的研究小组在珍珠贝中鉴定了 72 种独特的 SMPs，其中 Alveoline-like (Alv) 蛋白在珍珠贝和马氏珠母贝中被报道具有同源基因。在这项研究中，我们探索了 Alv 的全长 cDNA 序列及其在贝壳形成过程中的功能分析。推导出的蛋白质（Alv）分子量为 24.9 kDa，等电点为 11.34，进行了特征分析，并在体内和体外进行了功能分析。Alv 基因在套膜中高表达，并能对缺口损伤做出反应。通过注射重组 Alv(rAlv)抗体在体内抑制 Alv 蛋白的功能会破坏棱柱结构，但会加速珍珠母层的生长。Western blot 和免疫荧光染色显示，天然 Alv 存在于棱柱层和珍珠层的 EDTA 不溶性基质中，在内外棱柱层中具有不同的分布模式。总之，基质蛋白 Alv 的特性和功能分析可以扩展我们对基本基质蛋白及其在贝壳形成过程中的功能的理解。
