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.
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.[citation needed]