NKp46 ( gene: NCR1 ) is a receptor protein in the cell membrane of natural killer cells (NK cells ) is located higher in all mammals. NKp46 contributes to the ability of the killer cells to distinguish friend from foe ( cell) and brake according to the activity of killer cells, or to restart.


NK cells recognize this receptor with different target cells, are activated and destroy target cells. In this way the tumor cells and infected with bacteria or viruses, the cells can be eliminated.

Molecular structure

Structurally, the protein of two C2 -type immunoglobulin -like domains with a variable structure connector, a transmembrane region with characteristic positive and negatively charged amino acids and a small intracellular domain. There are three glycosylation sites.

Target structures

These are i.W. not known to be discussed are heparan sulfate proteoglycans to the cell surface and extracellularly accessible vimentin structurally uncharacterized but certainly ubiquitously occurring zellmembranexprimierte targets. In addition, on the neuramic acid Gylcosylierung recognizing viral molecules, such as influenza hemagglutinin and sialidase bound.

Targets expressing cells

Be detected tumor cells (for example, myeloma cells) and with intracellular pathogens (eg, mycobacteria / TB, Salmonella, trypanosomes ) and some viruses (eg, influenza, Sendai, vaccinia ) infected cells.

Signal transduction

With the transmembrane region binds NKp46 (via salt bridges ) to two molecules, the so-called CD3ζ and Fcy receptor; both have intracellularly via a so-called ITAM motif, which leads to activation of the small tyrosine kinase syk.

Expressing cells

Almost exclusively NK cells, and in all differentiation stages. Described is an atypical T-ALL cell line (NKT -like / NT -like), which is tested in clinical trials.

Functional defects

A reduced membrane expression of the three NCR we see in chronic hepatitis C and chronic HIV infection ..