A pattern recognition protein for peptidoglycan -: Cloning the cDNA and the gene of the silkworm, Bombyx mori
A pattern recognition protein for peptidoglycan -: Cloning the cDNA and the gene of the silkworm, Bombyx mori
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DOI：
10.1074/jbc.274.17.11854
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发表时间：
1999-04-23
影响因子：
4.8
通讯作者：
Ashida, M
中科院分区：
文献类型：
--
作者：
Ochiai, M;Ashida, M
肽聚糖识别蛋白（PGRP）是与肽聚糖特异性结合的蛋白质，被认为是昆虫先天免疫中的模式识别蛋白之一。PGRP是肽聚糖的重要组成部分，它能触发酚氧化酶原级联反应，酚氧化酶原级联反应被认为是昆虫的一种重要防御机制。北方杂交分析表明，PGRP基因在家蚕脂肪体、上皮细胞和血细胞中组成型表达。此外，细菌的挑战加强了基因的表达，与最大的时期是从感染后6至36小时。克隆的PGRP基因的上游序列显示含有推定的顺式调节元件，类似于NF-κ B样元件、干扰素应答半元件和加塔基序元件，这些元件已经在哺乳动物和昆虫的急性期蛋白基因的启动子中发现。同源性检索显示家蚕PGRP的同源物存在于小鼠、线虫和噬菌体中。这表明在脊椎动物和无脊椎动物中，具有进化上共同起源的PGRP同源物影响肽聚糖作为外源物的识别。
Peptidoglycan recognition protein (PGRP) specifically binds to peptidoglycan and is considered to be one of the pattern recognition proteins in the innate immunity of insect. The PGRP is an essential component for peptidoglycan to trigger the prophenoloxidase cascade that is now recognized to be an important insect defense mechanism, We cloned cDNA encoding PGRP from the silkworm fat body cDNA library. Northern blot analysis showed that the PGRP gene is constitutively expressed in the fat body, epithelial cell, and hemocytes of naive silkworms. Furthermore, a bacterial challenge intensified the gene expression, with the maximal period being from 6 to 36 h after infection. The upstream sequence of the cloned PGRP gene was shown to contain putative cis-regulatory elements similar to the NF-kappa B-like element, interferon-response half-element, and GATA motif element, which have been found in the promoters of the acute phase protein genes of mammals and insects. A homology search revealed that the homologs of silkworm PGRP are present in mice, nematodes, and bacteriophages, This suggests that the recognition of peptidoglycan as foreign is effected in both vertebrates and invertebrates by PGRP homologs with an evolutionally common origin.