Penaeus monodon Dscam (PmDscam) has a highly diverse cytoplasmic tail and is the first membrane-bound shrimp Dscam to be reported
Penaeus monodon Dscam (PmDscam) has a highly diverse cytoplasmic tail and is the first membrane-bound shrimp Dscam to be reported
复制标题
DOI：
10.1016/j.fsi.2011.02.009
复制
发表时间：
2011-04-01
影响因子：
4.7
通讯作者：
Wang, K. C. Han-Ching
中科院分区：
文献类型：
--
作者：
Chou, Pin-Hsiang;Chang, Hao-Shuo;Wang, K. C. Han-Ching
唐氏综合征细胞黏附分子(DSCAM)似乎在无脊椎动物的“另类适应性免疫”中起着关键作用。DSCAM由一个参与信号转导的细胞质尾巴和一个可能使用与脊椎动物抗体类似的病原体识别机制的高变胞外区组成。在我们之前的论文中，我们从凡纳滨对虾中分离到了一种独特的无尾形式的DSCAM。在本研究中，我们报道了第一个膜结合形式的对虾Dscam：PmDscam是从斑节对虾中分离出来的，它以膜结合和无尾两种形式存在。系统发育分析表明，虽然虾和水蚤的甲壳类Dscam不共享一个亚类，但它们与无脊椎动物Dscam类分子和昆虫纲Dscam不同。在胞外区，PmDscam可变区位于N端IG2、N端IG3和整个Ig7结构域。PmDscam胞外变异体和跨膜区变异体是由互斥的选择性剪接事件产生的。胞质尾部变异体由外显子包涵体/排斥体产生。基于Daphnia Dscam细胞质尾巴的基因组组织，我们提出了一个对虾Dscam基因组位点如何利用III型多聚腺苷来产生无尾和膜结合形式的模型。(C)2011爱思唯尔有限公司。保留所有权利。
Down syndrome cell adhesion molecule (Dscam) seems likely to play a key role in the "alternative adaptive immunity" that has been reported in invertebrates. Dscam consists of a cytoplasmic tail that is involved in signal transduction and a hypervariable extracellular region that might use a pathogen recognition mechanism similar to that used by the vertebrate antibodies. In our previous paper, we isolated a unique tail-less form of Dscam from Litopenaeus vannamei. In this study, we report the first membrane-bound form of shrimp Dscam: PmDscam was isolated from Penaeus monodon, and it occurred in both membrane-bound and tail-less forms. Phylogenetic analysis showed that while the crustacean Dscams from shrimp and water flea did not share a single subclade, they were distinct from the invertebrate Dscam-like molecules and from the insecta Dscams. In the extracellular region, the variable regions of PmDscam were located in N-terminal Ig2, N-terminal Ig3 and the entire Ig7 domain. The PmDscam extracellular variants and transmembrane domain variants were produced by mutually exclusive alternative splicing events. The cytoplasmic tail variants were produced by exon inclusion/exclusion. Based on the genomic organization of Daphnia Dscam's cytoplasmic tail, we propose a model of how the shrimp Dscam genomic locus might use Type III polyadenylation to generate both the tail-less and membrane-bound forms. (C) 2011 Elsevier Ltd. All rights reserved.