KAHRP explained

Knob-associated histidine-rich protein
Uniprot:	P09346
Organism:	Plasmodium falciparum

KAHRP (knob-associated histidine-rich protein) is a protein expressed by Plasmodium falciparum infecting erythrocytes. KAHRP is a major component of knobs, feature found on Plasmodium falciparum infected erythrocytes.

It has been suggested that KAHRP may play a role in trafficking or docking PfEMP1, major malarial cytoadherence protein to the erythrocyte membrane;^[1] however, these findings were disputed by recent NMR and fluorescence anisotropy studies showing no interaction between PfEMP1 and KAHRP.^[2]

Instead, KAHRP was shown to interact with Ankyrin, more precisely the D3 subunit of the Membrane-binding domain of Ankyrin type 1.^[3] This interaction was suggested via SPR, ELISA, and Pulldown studies, however, it has not been confirmed by NMR, ITC, crystallography, or fluorescence anisotropy.

Notes and References

1. Maier AG, Cooke BM, Cowman AF, Tilley L . Malaria parasite proteins that remodel the host erythrocyte . Nature Reviews. Microbiology . 7 . 5 . 341–54 . May 2009 . 19369950 . 10.1038/nrmicro2110 . 30624448 .
2. Mayer C, Slater L, Erat MC, Konrat R, Vakonakis I . Structural analysis of the Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) intracellular domain reveals a conserved interaction epitope . The Journal of Biological Chemistry . 287 . 10 . 7182–9 . March 2012 . 22249178 . 3293552 . 10.1074/jbc.M111.330779 . free .
3. Weng H, Guo X, Papoin J, Wang J, Coppel R, Mohandas N, An X . Interaction of Plasmodium falciparum knob-associated histidine-rich protein (KAHRP) with erythrocyte ankyrin R is required for its attachment to the erythrocyte membrane . Biochimica et Biophysica Acta (BBA) - Biomembranes . 1838 . 1 Pt B . 185–92 . January 2014 . 24090929 . 4403245 . 10.1016/j.bbamem.2013.09.014 .