KAHRP

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.

Knob-associated histidine-rich protein
Identifiers
Organism	Plasmodium falciparum
Symbol	?
UniProt	P09346
Search for Structures Swiss-model Domains InterPro

EMP3-KAHRP-like N-terminal domain
Identifiers
Symbol	EKAL
Pfam	PF17986
InterPro	IPR040805
Available protein structures: Pfam   structures / ECOD   PDB RCSB PDB; PDBe; PDBj PDBsum structure summary
EMP3 refers to "Erythrocyte membrane protein 3." It is likely a misnomer, as no reported PfEMP3 sequences contain this domain. PfEMP3 is arranged next to KAHRP in the P. falciparum genome, a probable cause of misidentification.

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.^{[citation needed]}

References

1. Maier AG, Cooke BM, Cowman AF, Tilley L (May 2009). "Malaria parasite proteins that remodel the host erythrocyte". Nature Reviews. Microbiology. 7 (5): 341–54. doi:10.1038/nrmicro2110. PMID 19369950. S2CID 30624448.
2. Mayer C, Slater L, Erat MC, Konrat R, Vakonakis I (March 2012). "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. doi:10.1074/jbc.M111.330779. PMC 3293552. PMID 22249178.
3. Weng H, Guo X, Papoin J, Wang J, Coppel R, Mohandas N, An X (January 2014). "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. doi:10.1016/j.bbamem.2013.09.014. PMC 4403245. PMID 24090929.