Cybb - cytochrome b-245, beta polypeptide

This gene encodes the heavy chain component of a heterodimeric transmembrane ion transporter composed of both a heavy and a light chain. This transporter mediates the transfer of electrons from nicotinamide adenine dinucleotide phosphate (NADPH) to oxygen to generate superoxide. This reaction is important in the innate immune response to pathogens. However, increased activity of the encoded protein also leads to the generation of reactive oxygen species that result in oxidative stress and can cause tissue damage. Conversely, loss of function of the related gene in human causes chronic granulomatous disease. Alternative splicing results in multiple transcript variants, although the full-length nature of some of these variants has not been determined. [provided by RefSeq, May 2013]