ADP-ribosyltransferase 4 (Dombrock blood group carrier) (ART4)

ADP-ribosyltransferase 4 (ART4), also known as Dombrock blood group carrier (CD297), is a glycosylphosphatidylinositol (GPI)-anchored membrane protein predominantly expressed on human erythrocytes and certain leukocytes. ART4 belongs to the ecto-ADP-ribosyltransferase family, containing a mono-ADP-ribosylation motif, but it lacks clear enzymatic activity in humans—the catalytically essential "active site" motif is altered and no ADP-ribosyltransferase function has been demonstrated experimentally. Instead, ART4 serves as the molecular carrier of Dombrock blood group antigens, with its allelic variation being significant for transfusion medicine due to the risk of adverse immune reactions. ART4 has also been implicated in membrane microdomain organization relevant to erythrocyte invasion by *Plasmodium falciparum*, suggesting possible roles in host–pathogen interactions and malaria susceptibility. Its physiological roles likely center on membrane protein structure, antigenic specificity for blood typing, and as a minor participant in cell signaling rather than a direct drug target.

Other names

Ecto-ADP-ribosyltransferase 4ART4CD297Dombrock blood group carrier moleculeDOK1ARTC4Do glycoproteinMono(ADP-ribosyl)transferase 4NAD(+)--protein-arginine ADP-ribosyltransferase 4NAD(P)(+)--arginine ADP-ribosyltransferase 4Dombrock glycoprotein