香港牡蛎新型LRR受体克隆与功能分析

亮氨酸富集重复(LRRs)是一种常见于膜上受体的多功能配体识别结构域,涉及机体发育、免疫应答及激素调控等重要生理过程。本实验通过基因克隆、序列比对分析、原位杂交、重组蛋白细胞体外处理等方法,对一种在胚胎发育时期显著高表达的香港牡蛎新型LRR受体进行了初步功能探究。SMART结构域预测结果显示,该新型LRR受体膜外区除了LRRs结构域外还含有一个免疫球蛋白样(immunoglobulin-like)结构域,是典型的I型跨膜蛋白,将其命名为香港牡蛎含LRRs和IG-like结构域受体(ChLIGR)。序列比对分析结果显示,ChLIGR是含IG-like结构域LRR蛋白超家族中的新成员,其同源蛋白多见于软体动物,但功能均未被揭示。胚胎发育各时期表达谱与胚胎整体原位杂交结果一致表明ChLIGR在囊胚期显著高表达,而且表达信号富集于胚胎局部。联合ChLIGR表达调控区含ETS/AP-1组合调控位点的预测结果,提出ChLIGR参与胚胎原肠胚化相关上皮间质细胞转换过程的猜想。ChLIGR膜外区重组蛋白体外处理显著促进细胞迁移相关基因的表达上调,为猜想提供了部分理论依据。综上所述,本研究初步揭示了香港牡蛎新型LRR受体在囊胚期促进细胞迁移,介导胚胎原肠胚化过程的重要作用。

Cloning and function analysis of novel LRRs receptor in Crassostrea hongkongensis

LRRs is a versatile ligand recognition and binding domain, which presents in various receptors as the vital function domain. In this article, the clone and function investigation of Leucine-rich repeats and IG-like containing Receptor in C.hongkongensis-ChLIGR was described. A typical LRRs and IG domain were identified in ChLIGR, the type I transmembrane receptor. The multi-alignment result showed that ChLIGR clustering with several undefined LRR proteins from mollusk constitude a unique group distinguished with most well-known LRR and IG domain containing receptor families. The remarkable ETS/AP-1sites were cognized in expression regulatory region of ChLIGR. The tissue specific expression pattern and expression assay during embryogenesis revealed that ChLIGR presented ubiquitously in all tissues while enriched in gill and labial palp. In particular, ChLIGR performed to significantly high express in blastula and gastula stages during embryogenesis. Of the in vitro ectdomain recombined protein treated assay, the N-Cadherin and MMP related genes were significantly up-regulated. This result showed that the ectdomain of ChLIGR can promote the cell migration and extracellular matrix reorganization. In conclusion, ChLIGR is likely to play a role in cell migration during embryogenesis.