非洲爪蟾中一种长型肽聚糖识别蛋白的克隆与表达分析(英文)

Cloning and expression analysis of a long type peptidoglycan recognition protein(PGRP-L) from Xenopus tropicalis

肽聚糖识别蛋白(peptidoglycan recognition proteins,PGRPs)是固有免疫系统中一类重要的模式识别受体。该文首次从两栖类模式生物-非洲爪蟾(Xenopus tropicalis)中克隆得到了一个长型PGRP(XtPGRP-L)基因。XtPGRP-L具有5个外显子和4个内含子的基因组结构,该结构在进化的过程中比较保守。序列比对与系统进化分析显示XtPGRP-L具有保守的酰胺酶活性位点。蛋白质建模显示XtPGRP-L拥有保守的3-D结构。实时定量PCR检测显示,XtPGRP-L在非洲爪蟾胚胎早期不表达,到72h蝌蚪期开始表达。在成体的肝脏、肺、肠和胃高表达。同时,在LPS刺激后,XtPGRP-L在肝脏、肠和胃中呈明显上调表达。结果表明,XtPGRP-L在非洲爪蟾固有免疫系统中可能具有重要的作用。

Peptidoglycan recognition proteins（PGRPs） are a family of pattern recognition receptors（PRRs） of the immune system,which bind and hydrolyze bacterial peptidoglycan.Here,a long type PGRP（PGRP-L） was first cloned in the lower vertebrate species Xenopus tropicalis（Xt）.The XtPGRP-L possessed a conserved genomic structure with five exons and four introns.The alignment and phylogenetic analysis indicated that XtPGRP-L might be a type of amidase-like PGRP.The 3-D model showed that XtPGRP-L possessed a conserved structure compared with the Drosophila PGRP-Lb.During embryonic development,XtPGRP-L was not expressed until the 72 h tadpole stage.In adult tissues,it was strongly expressed in the liver,lung,intestine,and stomach.Furthermore,after LPS stimulation,the expression of XtPGRP-L was up-regulated significantly in the liver,intestine and spleen,indicating that XtPGRP-L may play an important role in the innate immunity of Xenopus tropicalis.