10779/crick.12666827.v1
Suraya A Diaz
Suraya A
Diaz
Stephen R Martin
Stephen R
Martin
Steven A Howell
Steven A
Howell
Munira Grainger
Munira
Grainger
Robert W Moon
Robert W
Moon
Judith L Green
Judith L
Green
Anthony A Holder
Anthony A
Holder
The binding of Plasmodium falciparum adhesins and erythrocyte invasion proteins to aldolase is enhanced by phosphorylation
The Francis Crick Institute
2020
Animals
Binding, Competitive
Erythrocytes
Fructose-Bisphosphate Aldolase
Green Fluorescent Proteins
Interferometry
Kinetics
Merozoites
Parasites
Phosphorylation
Plasmodium falciparum
Protein Binding
Protein Domains
Protozoan Proteins
Recombinant Fusion Proteins
Holder FC001097
SB
PRT
General Science & Technology
2020-07-17 16:35:23
Journal contribution
https://crick.figshare.com/articles/journal_contribution/The_binding_of_Plasmodium_falciparum_adhesins_and_erythrocyte_invasion_proteins_to_aldolase_is_enhanced_by_phosphorylation/12666827
Aldolase has been implicated as a protein coupling the actomyosin motor and cell surface adhesins involved in motility and host cell invasion in the human malaria parasite Plasmodium falciparum. It binds to the cytoplasmic domain (CTD) of type 1 membrane proteins of the thrombospondin-related anonymous protein (TRAP) family. Other type 1 membrane proteins located in the apical organelles of merozoites, the form of the parasite that invades red blood cells, including apical membrane antigen 1 (AMA1) and members of the erythrocyte binding ligand (EBL) and reticulocyte binding homologue (RH) protein families have been implicated in host cell binding and invasion. Using a direct binding method we confirm that TRAP and merozoite TRAP (MTRAP) bind aldolase and show that the interaction is mediated by more than just the C-terminal six amino acid residues identified previously. Single amino acid substitutions in the MTRAP CTD abolished binding to aldolase. The CTDs of AMA1 and members of the EBL and RH protein families also bound to aldolase. MTRAP competed with AMA1 and RH4 for binding to aldolase, indicating overlapping binding sites. MTRAP CTD was phosphorylated in vitro by both calcium dependent kinase 1 (CDPK1) and protein kinase A, and this modification increased the affinity of binding to aldolase by ten-fold. Phosphorylation of the CTD of members of the EBL and RH protein families also increased their affinity for aldolase in some cases. To examine whether or not MTRAP expressed in asexual blood stage parasites is phosphorylated, it was tagged with GFP, purified and analysed, however no phosphorylation was detected. We propose that CTD binding to aldolase may be dynamically modulated by phosphorylation, and there may be competition for aldolase binding between different CTDs. The use and efficiency of alternate invasion pathways may be determined by the affinity of adhesins and cell invasion proteins for aldolase, in addition to their host ligand specificity.