Fish Immunology and Vaccinology Group, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal.
Fish Shellfish Immunol. 2013 Oct;35(4):1163-75. doi: 10.1016/j.fsi.2013.07.024. Epub 2013 Jul 21.
PDI (PDIA1) and ERp57 (PDIA3), members of the PDI family and of the thioredoxin (Trx) superfamily, are multifunctional proteins with wide physiological roles and have been implicated in several pathologies. Importantly, they are both involved in the MHC class I antigen presentation pathway. This paper reports the isolation and characterization of full cDNA and genomic clones from sea bass (Dicentrarchus labrax, L.) PDI (Dila-PDI) and ERp57 (Dila-ERp57). The genes are ~12.4 and ~7.1 kb long, originating 2155 and 2173 bp transcripts and encoding 497 and 484 amino acids mature proteins, for Dila-PDI and -ERp57, respectively. The PDI gene consists of eleven exons and ERp57 of thirteen. As described in other species, both molecules are composed of four Trx-like domains (abb'a') followed by a C-terminal tail, retaining two CGHC active sites and an ER-signalling sequence, suggestive of a conserved function. Additionally, three-dimensional homology models further support Dila-PDI and Dila-ERp57 as orthologs of mammalian PDI and ERp57, respectively. Finally, high similarity is observed to their vertebrate counterparts (>69% identity), especially among the few ones from closely related teleosts (>79% identity). Hence, these results provide relevant primary data and will enable further studies to clarify the roles of PDI and ERp57 in European sea bass immunity.
PDI（PDIA1）和 ERp57（PDIA3）是 PDIs 家族和硫氧还蛋白（Trx）超家族的成员，是具有广泛生理作用的多功能蛋白，与多种病理学有关。重要的是，它们都参与 MHC I 类抗原呈递途径。本文报告了从鲈鱼（Dicentrarchus labrax，L.）PDI（Dila-PDI）和 ERp57（Dila-ERp57）中分离和鉴定全长 cDNA 和基因组克隆。基因分别约 12.4 和 7.1 kb 长，起始转录物分别为 2155 和 2173 bp，并分别编码 497 和 484 个氨基酸成熟蛋白。PDI 基因由 11 个外显子组成，ERp57 由 13 个外显子组成。与其他物种描述的一样，这两种分子都由四个 Trx 样结构域（abb'a'）组成，后面是一个 C 端尾部，保留了两个 CGHC 活性位点和一个 ER 信号序列，表明具有保守的功能。此外，三维同源模型进一步支持 Dila-PDI 和 Dila-ERp57 分别为哺乳动物 PDI 和 ERp57 的同源物。最后，与脊椎动物的同源物（>69%的同一性）高度相似，尤其是亲缘关系较近的硬骨鱼中的几个同源物（>79%的同一性）。因此，这些结果提供了相关的原始数据，并将有助于进一步研究阐明 PDI 和 ERp57 在欧洲鲈鱼免疫中的作用。
