Ligand-induced dimerization of Drosophila peptidoglycan recognition proteins in vitro.
Drosophila knockout mutants have placed peptidoglycan recognition proteins (PGRPs) in the two major pathways controlling immune gene expression. We now examine PGRP affinities for peptidoglycan. PGRP-SA and PGRP-LCx are bona fide pattern recognition receptors, and PGRP-SA, the peptidoglycan receptor of the Toll/Dif pathway, has selective affinity for different peptidoglycans. PGRP-LCx, the default peptidoglycan receptor of the Imd/Relish pathway, has strong affinity for all polymeric peptidoglycans tested and for monomeric peptidoglycan. PGRP-LCa does not have affinity for polymeric or monomeric peptidoglycan. Instead, PGRP-LCa can form heterodimers with LCx when the latter is bound to monomeric peptidoglycan. Hence, PGRP-LCa can be said to function as an adaptor, thus adding a new function to a member of the PGRP family.
Mellroth
Peter
P
Department of Genetics, Microbiology, and Toxicology, University of Stockholm, S-106 91 Stockholm, Sweden.
Karlsson
Jenny
J
Håkansson
Janet
J
Schultz
Niklas
N
Goldman
William E
WE
Steiner
Håkan
H
D000818:Animals; D001419:Bacteria / Q000276:immunology / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D002473:Cell Wall / Q000378:metabolism; D019281:Dimerization; D004330:Drosophila / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D005822:Genetic Vectors / Q000235:genetics; D007150:Immunohistochemistry; D008024:Ligands; D008954:Models, Biological; D009943:Organophosphorus Compounds; D010457:Peptidoglycan / Q000378:metabolism*; D020539:Sequence Analysis, Protein; D015398:Signal Transduction / Q000276:immunology*
C043517:2-(4-isothiocyanatophenoxy)-1,3,2-dioxaphosphinene 2-oxide; D002352:Carrier Proteins; D008024:Ligands; D009943:Organophosphorus Compounds; D010457:Peptidoglycan; C118897:peptidoglycan recognition protein