PR3 (F5M5D) Rabbit mAb #37592

Proteinase 3 (PR3 or PRTN3), also known as myeloblastin, is a serine protease primarily expressed in neutrophils (1). PR3 can be localized to both azurophilic granules and the plasma membrane, where it serves as a target of the autoantibody antineutrophil cytoplasmic antibody (ANCA) in the autoimmune condition granulomatosis with polyangiitis, formerly known as Wegener's granulomatosis (2). PR3 can degrade elastin, a component of the extracellular matrix, and can activate platelets, dendritic cells, and endothelial cells by interacting with the proteinase-activated receptors (PARs), PAR-1 and PAR-2 (3-6). PR3 is also capable of processing inflammatory cytokines, including TNF-α, IL-1β, and IL-18 (7). PR3 has recently been shown to play a role in hematopoietic differentiation by participating in the cleavage of histone H3. Through its ability to modulate Stat3 to promote myeloid differentiation, it may serve as a therapeutic target in acute myeloid leukemia (7,8).