p67phox Rabbit Polyclonal Antibody

p67phox protein (also known as NOXA2, neutrophil cytosolic factor 2) is a key cytosolic regulatory subunit of the NADPH oxidase complex, which is highly expressed primarily in phagocytes and plays a central role in host immune defense. This protein contains multiple tetratricopeptide repeat (TPR) domains and a PX domain, among which the TPR domains are responsible for high-affinity interactions with p47phox to mediate complex assembly, while the PX domain specifically binds phosphatidylinositol-3,4-bisphosphate (PI(3,4)P₂), helping to anchor the entire regulatory complex to the cell membrane and ensuring spatial precision of activation signals. Upon cellular stimulation, p67phox cooperates with p47phox and p40phox through its SH3 and PB1 domains, respectively, while its C-terminal Rac-binding site is responsible for directly binding to the activated small GTPase Rac (such as Rac1 or Rac2). This binding triggers a conformational change in p67phox, which in turn presents its N-terminal activation domain to the catalytic subunit gp91phox (i.e., NOX2), facilitating electron transfer from NADPH to FAD and ultimately initiating the burst generation of superoxide anions. Functional defects or gene mutations in this protein can directly lead to one subtype of chronic granulomatous disease (CGD), in which patients' neutrophils exhibit severely impaired respiratory burst activity, resulting in recurrent and severe bacterial and fungal infections—highlighting the irreplaceable role of p67phox in innate immunity.