肽聚糖识别蛋白(PGRPs)是一类可识别肽聚糖和含肽聚糖的**的模式识别受体，过去的研究证实PGRPs在天然**中发挥着重要的识别和调节功能。
早在2001年第安纳大学医学院微生物学及**学教授RomanDziarski就与他的同事生物化学和分子生物学系副教授DipikaGupta**克隆了PGRP基因。随后，研究人员证实PGRP广泛地存在于从昆虫到哺乳动物等物种中，在机体的先天**系统中起重要作用。
PGRP蛋白通常表达于血液的吞噬细胞及皮肤、口腔、肠道及其他与外界有着直接或间接接触的组织中。在某些组织中PGRPs参与维持机体与某些有益菌的相对平衡。一些研究表明PGRP蛋白质缺失可导致炎性肠病。然而直到现在科学家们对于PGRPs靶向杀死**的机制并不是很清楚。
在这篇文章中，Dziarski领导的研究小组证实PGRPs是通过结合到**细胞壁的特异性位点，进而利用一种称为“蛋白质传感双组份系统”（protein-sensing two-componentsystem）的**防御机制靶向性诱导**发生**反应的。正常情况下**通常利用这一系统检测并**例如PGRPs一类的“畸形”蛋白质。而当无法**PGRPs时，**则会启动**反应。
“这种**机制与其他例如**系统白细胞采用的**机制完全不同。我们的研究发现为开发出新的**策略提供了一个新方向，”Dziarski说。
推荐原文检索：
Peptidoglycan recognition proteins kill bacteria by activatingprotein-sensing two-component systems
Mammalian peptidoglycan recognition proteins (PGRPs), similar toantimicrobial lectins, bind the bacterial cell wall and killbacteria through an unknown mechanism. We show that PGRPs enter theGram-positive cell wall at the site of daughter cell separationduring cell division. In Bacillus subtilis, PGRPs activate theCssR-CssS two-component system that detects and disposes ofmisfolded proteins that are usually exported out of bacterialcells. This activation results in membrane depolarization,cessation of intracellular peptidoglycan, protein, RNA and DNAsynthesis, and production of hydroxyl radicals, which areresponsible for bacterial death. PGRPs also bind the outer membraneof Escherichia coli and activate the functionally homologousCpxA-CpxR two-component system, which kills the bacteria. Weexclude other potential bactericidal mechanisms, includinginhibition of extracellular peptidoglycan synthesis, hydrolysis ofpeptidoglycan and membrane permeabilization. Thus, we reveal apreviously unknown mechanism by which innate immunity proteins thatbind the cell wall or outer membrane exploit the bacterial stressdefense response to kill bacteria.