COX4-I2 Proteins and Enzymes

COX4-1 (Cytochrome c oxidase subunit 4 isoform 1) is a 21-22 kDa member of the Cytochrome c oxidase IV family of proteins and is predominantly expressed in lung. It is a component of COX, an inner mitochondrial membrane multimeric dimer that catalyzes the transfer of electrons from Cytochrome c to dioxygen. COX4-I2 is induced following blockade of mitochondrial respiration, leading to increased production of reactive oxygen species and necrosis. The ubiquitously expressed COX4-I1 is the product of a different gene and shares only 50% aa identity with COX4-I2.