NCF4
NCF4 (neutrophil cytosolic factor 4, also known as p40phox or SH3PXD4) is a cytosolic regulatory subunit of the phagocyte NADPH oxidase complex. It supports the production of superoxide, a reaction central to host defence. Browse Assay Genie's current range of NCF4 research reagents below, or read on for the biology behind the target.
NCF4 is a subunit of the phagocyte NADPH oxidase complex, which transfers electrons from cytosolic NADPH to molecular oxygen to produce the superoxide anion. In the activated complex, electrons pass from NADPH to flavin adenine dinucleotide (FAD) and then via two haem molecules to oxygen. Activation begins when the cytosolic subunits assemble with the core complex at the plasma membrane or phagosomal membrane. This is initiated by phosphorylation-dependent binding of the cytosolic NCF1 (p47-phox) subunit to the C-terminus of CYBA (p22-phox).
The NCF4 protein is a cytosolic regulatory component of this multicomponent enzyme system and is preferentially expressed in cells of myeloid lineage. It interacts primarily with NCF2 (p67-phox) and forms a complex with NCF1. This complex interacts with the small G protein RAC1 and translocates to the membrane on cell stimulation, where it activates flavocytochrome b, the membrane-integrated catalytic core of the oxidase. The PX domain of NCF4 binds phospholipid products of PI(3) kinase, which suggests a role in PI(3) kinase-mediated signalling. Phosphorylation of the protein negatively regulates enzyme activity. UniProt records localisation to the cytosol, the endosome membrane and membranes more generally.
The NCF4 gene belongs to the HGNC group of SH3 domain containing proteins. Its previous names include neutrophil cytosolic factor 4 (40kD), and the mouse ortholog is Ncf4. Alternatively spliced transcript variants encoding distinct isoforms have been observed, which is worth bearing in mind when choosing reagents for NCF4 antibody or NCF4 ELISA kit based work.
NCF4 is a subunit of the complex that transfers electrons from NADPH to oxygen to generate superoxide.
As a regulatory component of the superoxide-producing oxidase, NCF4 is relevant to studies of host defence.
NCF4 is preferentially expressed in cells of myeloid lineage, making it a useful focus for myeloid cell function.
The PX domain of NCF4 binds PI(3) kinase phospholipid products, linking it to PI(3) kinase-mediated signalling events.
NCF4 is a cytosolic regulatory subunit of the phagocyte NADPH oxidase. It interacts with NCF2 and NCF1, and with RAC1, to translocate to the membrane on stimulation and activate flavocytochrome b, which produces superoxide. Its phosphorylation negatively regulates enzyme activity.
NCF4 is also called p40phox and SH3PXD4. Its HGNC name is neutrophil cytosolic factor 4, and earlier names include neutrophil cytosolic factor 4 (40kD). UniProt lists the protein as neutrophil cytosol factor 4. Alternatively spliced transcripts encode distinct isoforms.
A mouse ortholog, Ncf4, is recorded for the human NCF4 gene. The source data do not list a rat ortholog. Cross-species use of any reagent depends on its reactivity, so check the datasheet of any product for its validated reactivity.
Other NADPH oxidase cytosolic subunits that assemble with NCF4 in the phagocyte oxidase complex.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q15080; product specifications from Assay Genie datasheets.