Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, PR China.
Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, PR China; Novoprotein Scientific Inc., Wujiang, Jiangsu 215200, PR China.
Int J Biol Macromol. 2019 May 15;129:538-551. doi: 10.1016/j.ijbiomac.2019.02.013. Epub 2019 Feb 4.
Hemocyanins (Hc), the main protein components of hemolymph in invertebrates, are not only involved in oxygen transport but also linked to non-specific immune responses. In this study, we used abalone (Haliotis diversicolor) Hc to study the basis of its diversified functions through gene, protein, peptides, and phenoloxidase (PO) activity levels. Three complete hemocyanin gene (HdH) sequences were cloned for the first time. By comparing the copies and location of HdH between abalone and other mollusks, we propose that Hc gene duplication and linkage is likely to be common during the evolution of mollusk respiratory proteins. We further demonstrate that all three genes could be expressed in abalone, with expression varying based on the developmental stages, tissue types, and different pathogen infections. However, HdH1 and HdH2 appear to be synthesized by the same cells by fluorescence in situ hybridization. Furthermore, the PO activity of HdH can be induced by trypsin, urea, and SDS in vitro. Viral infection can stimulate its PO activity in vivo by cleaving the protein into fragments. Consequently, we present a comprehensive study of abalone hemocyanin, providing important evidence for an in-depth understanding of the physiological and immune functions of Hc in mollusks.
血蓝蛋白（Hc）是无脊椎动物血淋巴中的主要蛋白质成分，不仅参与氧气运输，还与非特异性免疫反应有关。在这项研究中，我们使用鲍鱼（Haliotis diversicolor）的 Hc 通过基因、蛋白质、肽和酚氧化酶（PO）活性水平来研究其多样化功能的基础。我们首次克隆了三个完整的血蓝蛋白基因（HdH）序列。通过比较鲍鱼和其他软体动物之间 HdH 的拷贝数和位置，我们提出 Hc 基因的复制和连锁可能在软体动物呼吸蛋白的进化过程中很常见。我们进一步证明，所有三个基因都可以在鲍鱼中表达，其表达因发育阶段、组织类型和不同病原体感染而异。然而，荧光原位杂交显示 HdH1 和 HdH2 似乎是由相同的细胞合成的。此外，PO 可以体外诱导 HdH 的活性，其机制可能是通过将蛋白质切割成片段。因此，我们对鲍鱼血蓝蛋白进行了全面研究，为深入了解 Hc 在软体动物中的生理和免疫功能提供了重要证据。
