Laboratory of Invertebrate Immunological Defense & Reproductive Biology, School of Life Sciences, East China Normal University, Shanghai, China.
Laboratory of Invertebrate Immunological Defense & Reproductive Biology, School of Life Sciences, East China Normal University, Shanghai, China.
Dev Comp Immunol. 2023 Jan;138:104541. doi: 10.1016/j.dci.2022.104541. Epub 2022 Sep 13.
As the most typical example of mRNA variable splicing, Down Syndrome Cell Adhesion Molecule (Dscam) can produce a large number of mRNA isomers. It plays an important role not only in the nervous system, but also in the immune system. In Eriocheir sinensis, the extracellular region of Dscam has three variable domains, which can produce 25, 34 and 18 exons and encode the N-terminal region of immunoglobulin (Ig) 2 and Ig3 domains, and the entire Ig7 domain, respectively. In addition to three variable domains, the extracellular non-variable region of Dscam also includes many Ig domains and fibronectin type III (FNIII) domains. However, the role of the extracellular non-variable region function of Dscam in the immune defense of E. sinensis is unclear. In this study, we focused on the role of the extracellular non-variable region of Dscam in crab immune defense. The results indicate that the extracellular non-variable region of Dscam can bind bacteria and has bacteriostatic function. At the same time, the extracellular non-variable region of Dscam can also directly promote bacterial clearance by promoting phagocytosis of hemocytes.
作为 mRNA 可变剪接的最典型范例，唐氏综合征细胞黏附分子（Down Syndrome Cell Adhesion Molecule，Dscam）可产生大量的 mRNA 异构体。它不仅在神经系统中发挥重要作用，而且在免疫系统中也发挥着重要作用。在中华绒螯蟹（Eriocheir sinensis）中，Dscam 的细胞外区具有三个可变结构域，可产生 25、34 和 18 个外显子，并分别编码免疫球蛋白（Ig）2 和 Ig3 结构域的 N 端区域以及整个 Ig7 结构域。除了三个可变结构域外，Dscam 的细胞外非可变区还包含许多 Ig 结构域和纤维连接蛋白 III（fibronectin type III，FNIII）结构域。然而，Dscam 细胞外非可变区在中华绒螯蟹免疫防御中的作用尚不清楚。在这项研究中，我们专注于 Dscam 细胞外非可变区在螃蟹免疫防御中的作用。结果表明，Dscam 的细胞外非可变区可与细菌结合并具有抑菌作用。同时，Dscam 的细胞外非可变区还可通过促进血细胞吞噬作用直接促进细菌清除。
