Peptidoglycan recognition protein (PGRP)

Peptidoglycan recognition proteins (PGRPs) are pattern recognition molecules that recognize bacteria and their unique cell wall component, peptidoglycan (PGN). Mammals have four PGRPs, designated in humans PGRP-S(24kDa), PGRPL( 60~65kDa), PGRP-Iα(38kDa), and PGRPIβ( 44kDa). Human PGRPs are differentially expressed in various tissues and organs: PGRP-S mainly in the bone marrow and Polymorphonuclear leukocyte (PMNs), PGRP-L mainly in the liver, and PGRP-Ia and PGRP-Ib mainly in the esophagus. The function of only one mammalian PGRP, PGRP-S, is currently known. Mouse PGRP-S is present in neutrophils and inhibits growth of Gram-positive bacteria and, therefore, may function as a neutrophil antibacterial protein.