Functional analysis of the three major PGRPLC isoforms in the midgut of the malaria mosquito Anopheles coluzzii

Insect Biochem Mol Biol. 2020 Mar;118:103288. doi: 10.1016/j.ibmb.2019.103288. Epub 2019 Nov 21.


Peptidoglycan recognition proteins (PGRPs) constitute the primary means of bacterial recognition in insects. Recent work in the model organism Drosophila has revealed the mechanisms by which the complement of PGRPs refine the sensitivity of different tissues to bacterial elicitors, permitting the persistence of commensal bacteria in the gut whilst maintaining vigilance against bacterial infection. Here, we use in vivo knockdowns and in vitro pull-down assays to investigate the role of the three major isoforms of the transmembrane receptor of the Imd pathway, PGRPLC, in basal immunity in the Anopheles coluzzii mosquito midgut. Our results indicate that the mosquito midgut is regionalized in its expression of immune effectors and of PGRPLC1. We show that PGRPLC1 and PGRPLC3 are pulled down with polymeric DAP-type peptidoglycan, while PGRPLC2 and PGRPLC3 co-precipitate in the presence of TCT, a peptidoglycan monomer. These data suggest that, as found in Drosophila, discrimination of polymeric and monomeric PGN by Anopheles PGRPLC participates in the regulation of the Imd pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anopheles / genetics*
  • Anopheles / metabolism
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Female
  • Gastrointestinal Tract / metabolism
  • Insect Proteins / genetics*
  • Insect Proteins / metabolism
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism


  • Carrier Proteins
  • Insect Proteins
  • Protein Isoforms
  • peptidoglycan recognition protein