A G-protein-coupled chemoattractant receptor recognizes lipopolysaccharide for bacterial phagocytosis

Citations Over TimeTop 17% of 2018 papers

Abstract

Phagocytes locate microorganisms via chemotaxis and then consume them using phagocytosis. Dictyostelium amoebas are stereotypical phagocytes that prey on diverse bacteria using both processes. However, as typical phagocytic receptors, such as complement receptors or Fcγ receptors, have not been found in Dictyostelium, it remains mysterious how these cells recognize bacteria. Here, we show that a single G-protein-coupled receptor (GPCR), folic acid receptor 1 (fAR1), simultaneously recognizes the chemoattractant folate and the phagocytic cue lipopolysaccharide (LPS), a major component of bacterial surfaces. Cells lacking fAR1 or its cognate G-proteins are defective in chemotaxis toward folate and phagocytosis of Klebsiella aerogenes. Computational simulations combined with experiments show that responses associated with chemotaxis can also promote engulfment of particles coated with chemoattractants. Finally, the extracellular Venus-Flytrap (VFT) domain of fAR1 acts as the binding site for both folate and LPS. Thus, fAR1 represents a new member of the pattern recognition receptors (PRRs) and mediates signaling from both bacterial surfaces and diffusible chemoattractants to reorganize actin for chemotaxis and phagocytosis.

Related Papers

• → Analysis of Chemotaxis in Dictyostelium(2011)35 cited
• → Differentiation-Inducing Factor-1 and -2 Function also as Modulators for Dictyostelium Chemotaxis(2009)34 cited
• → Chemotaxis: Under Agarose Assay(2015)3 cited
• Instrinsic defect of the polymorphonuclear leucocyte resulting in impaired chemotaxis and phagocytosis.(1971)
• → The Role of PI3 Kinase in Directional Sensing during Chemotaxis in Dictyostelium, a Model for Chemotaxis of Neutrophils and Macrophages(2003)