Laboratorio di Genetica, Department of Life Sciences, University of Trieste, Trieste, Italy.
Dev Comp Immunol. 2012 Feb;36(2):390-9. doi: 10.1016/j.dci.2011.08.003. Epub 2011 Aug 18.
Antimicrobial peptides (AMPs) play a fundamental role in the innate immunity of invertebrates, preventing the invasion of potential pathogens. Mussels can express a surprising abundance of cysteine-rich AMPs pertaining to the defensin, myticin, mytilin and mytimycin families, particularly in the circulating hemocytes. Based on deep RNA sequencing of Mytilus galloprovincialis, we describe the identification, molecular diversity and constitutive expression in different tissues of five novel transcripts pertaining to the macin family (named mytimacins) and eight novel transcripts pertaining to the big defensins family (named MgBDs). The predicted antimicrobial peptides exhibit a N-terminal signal peptide, a positive net charge and a high content in cysteines, allegedly organized in intra-molecular disulfide bridges. Mytimacins and big defensins therefore represent two novel AMP families of M. galloprovincialis which extend the repertoire of cysteine-rich AMPs in this bivalve mollusk.
抗菌肽（AMPs）在无脊椎动物的先天免疫中发挥着重要作用，可防止潜在病原体的入侵。贻贝可表达大量富含半胱氨酸的 AMPs，包括防御素、肌肽、肌肽和肌肽霉素家族，尤其是在循环血细胞中。基于对马氏珠母贝的深度 RNA 测序，我们描述了 5 种新型马氏肌肽家族（命名为肌肽霉素）和 8 种新型大防御素家族（命名为 MgBDs）的新型转录本的鉴定、分子多样性和在不同组织中的组成型表达。预测的抗菌肽具有 N 端信号肽、正净电荷和高半胱氨酸含量，据称这些半胱氨酸以分子内二硫键的形式存在。因此，肌肽霉素和大防御素代表了马氏珠母贝中的两种新型 AMP 家族，它们扩展了这种双壳贝类富含半胱氨酸的 AMP repertoire。
