Using mutagenesis and structural biology to map the binding site for the Plasmodium falciparum merozoite protein PfRh4 on the human immune adherence receptor
- Author(s)
- Park, HJ; Guariento, M; Maciejewski, M; Hauhart, R; Tham, WH; Cowman, AF; Schmidt, CQ; Mertens, HDT; Liszewski, MK; Hourcade, DE; Barlow, PN; Atkinson, JP;
- Details
- Publication Year 2014-01,Volume 289,Issue #1,Page 450-463
- Journal Title
- Journal of Biological Chemistry
- Publication Type
- Journal Article
- Abstract
- To survive and replicate within the human host, malaria parasites must invade erythrocytes. Invasion can be mediated by the P. falciparum reticulocyte-binding homologue protein 4 (PfRh4) on the merozoite surface interacting with complement receptor type 1 (CR1, CD35) on the erythrocyte membrane. The PfRh4 attachment site lies within the three N-terminal complement control protein modules (CCPs 1-3) of CR1, which intriguingly also accommodate binding and regulatory sites for the key complement activation-specific proteolytic products, C3b and C4b. One of these regulatory activities is decay-accelerating activity. Although PfRh4 does not impact C3b/C4b binding, it does inhibit this convertase disassociating capability. Here, we have employed ELISA, co-immunoprecipitation, and surface plasmon resonance to demonstrate that CCP 1 contains all the critical residues for PfRh4 interaction. We fine mapped by homologous substitution mutagenesis the PfRh4-binding site on CCP 1 and visualized it with a solution structure of CCPs 1-3 derived by NMR and small angle x-ray scattering. We cross-validated these results by creating an artificial PfRh4-binding site through substitution of putative PfRh4-interacting residues from CCP 1 into their homologous positions within CCP 8; strikingly, this engineered binding site had an approximate to 30-fold higher affinity for PfRh4 than the native one in CCP 1. These experiments define a candidate site on CR1 by which P. falciparum merozoites gain access to human erythrocytes in a non-sialic acid-dependent pathway of merozoite invasion.
- Publisher
- AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY
- Keywords
- Cell Surface Receptor Complement System Convertases Malaria
- Research Division(s)
- Infection And Immunity
- Publisher's Version
- https://doi.org/10.1074/jbc.M113.520346
- Terms of Use/Rights Notice
- © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.
Creation Date: 2014-04-30 04:00:44
Last Modified: 2015-09-04 11:58:23