BACKGROUND The shells of various Haliotis species have served as models of invertebrate biomineralization and physical shell properties for more than 20 years. A focus of this research has been the nacreous inner layer of the shell with its conspicuous arrangement of aragonite platelets, resembling in cross-section a brick-and-mortar wall. In comparison, the outer, less stable, calcitic prismatic layer has received much less attention. One of the first molluscan shell proteins to be characterized at the molecular level was Lustrin A, a component of the nacreous organic matrix of Haliotis rufescens. This was soon followed by the C-type lectin perlucin and the growth factor-binding perlustrin, both isolated from H. laevigata nacre, and the crystal growth-modulating AP7 and AP24, isolated from H. rufescens nacre. Mass spectrometry-based proteomics was subsequently applied to to Haliotis biomineralization research with the analysis of the H. asinina shell matrix and yielded 14 different shell-associated proteins. That study was the most comprehensive for a Haliotis species to date. METHODS The shell proteomes of nacre and prismatic layer of the marine gastropod Haliotis laevigata were analyzed combining mass spectrometry-based proteomics and next generation sequencing. RESULTS We identified 297 proteins from the nacreous shell layer and 350 proteins from the prismatic shell layer from the green lip abalone H. laevigata. Considering the overlap between the two sets we identified a total of 448 proteins. Fifty-one nacre proteins and 43 prismatic layer proteins were defined as major proteins based on their abundance at more than 0.2% of the total. The remaining proteins occurred at low abundance and may not play any significant role in shell fabrication. The overlap of major proteins between the two shell layers was 17, amounting to a total of 77 major proteins. CONCLUSIONS The H. laevigata shell proteome shares moderate sequence similarity at the protein level with other gastropod, bivalve and more distantly related invertebrate biomineralising proteomes. Features conserved in H. laevigata and other molluscan shell proteomes include short repetitive sequences of low complexity predicted to lack intrinsic three-dimensional structure, and domains such as tyrosinase, chitin-binding, and carbonic anhydrase. This catalogue of H. laevigata shell proteins represents the most comprehensive for a haliotid and should support future efforts to elucidate the molecular mechanisms of shell assembly.

中文翻译：

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Haliotis laevigata（绿边鲍鱼）珍珠层和棱柱有机壳基质的深入蛋白质组学分析。

背景技术 20 多年来，各种 Haliotis 物种的壳已作为无脊椎动物生物矿化和物理壳特性的模型。这项研究的一个重点是贝壳的珠光内层，其具有明显排列的文石片晶，其横截面类似于砖墙。相比之下，外部的、不太稳定的方解石棱柱层受到的关注要少得多。第一个在分子水平上进行表征的软体动物壳蛋白之一是 Lustrin A，它是 Haliotis rufescens 珠光有机基质的一种成分。紧随其后的是 C 型凝集素 perlucin 和生长因子结合 perlustrin，两者均从 H. laevigata nacre 中分离，以及晶体生长调节 AP7 和 AP24，从 H. rufescens nacre 中分离。随后将基于质谱的蛋白质组学应用于 Haliotis 生物矿化研究，分析了 H. asinina 壳基质，并产生了 14 种不同的壳相关蛋白。该研究是迄今为止对 Haliotis 物种最全面的研究。方法结合基于质谱的蛋白质组学和二代测序对海洋腹足动物Haliotis laevigata珍珠层和棱柱层的壳蛋白质组进行分析。结果 我们从绿唇鲍鱼珠光壳层中鉴定出 297 种蛋白质，从棱柱形壳层中鉴定出 350 种蛋白质。考虑到两组之间的重叠，我们总共确定了 448 种蛋白质。51 种珍珠层蛋白和 43 种棱柱层蛋白被定义为主要蛋白质，基于它们的丰度超过总数的 0.2%。剩余的蛋白质以低丰度出现，可能在外壳制造中不起任何重要作用。两个壳层之间主要蛋白质的重叠为17个，共计77个主要蛋白质。结论 H. laevigata 壳蛋白质组在蛋白质水平上与其他腹足动物、双壳类和更远亲的无脊椎动物生物矿化蛋白质组具有中等序列相似性。在 H. laevigata 和其他软体动物壳蛋白质组中保守的特征包括预计缺乏内在三维结构的低复杂性的短重复序列，以及酪氨酸酶、几丁质结合和碳酸酐酶等结构域。这个 H. laevigata 壳蛋白目录代表了最全面的 haliotid，应该支持未来阐明壳组装分子机制的努力。