A species-conserved NK cell antigen receptor is a novel vimentin-like molecule

The role of a novel, evolutionarily conserved function-associated molecule (FAM) in NK cell function has been examined in several species. This molecule has previously been shown to mediate NK and NK-like recognition functions in fish NCC and human NK cells. We now show that this molecule is distributed in those tissues that contain NK cells in mice and rats. Further, we show that this molecule functions as an antigen receptor on NK cells of these species. That is, monoclonal antibodies directed against this FAM inhibit NK cell cytotoxic function and trigger signal transduction pathways in each of the species. Finally, we present evidence that this putative antigen receptor is a vimentin-like molecule which functions to mediate all NK or NK-like recognition functions in a variety of species.