CYGB Human

Cytoglobin (Cygb) is a member of the globin family, which includes well-known proteins such as hemoglobin and myoglobin. It was discovered in 2001 and named in 2002 . Cytoglobin is a ubiquitously expressed hexacoordinate hemoglobin that plays a crucial role in various physiological processes .

Cytoglobin is a 21-kDa protein consisting of 190 amino acids . Unlike other globins, mammalian cytoglobin is extended at both its termini . It facilitates the diffusion of oxygen through tissues, scavenges nitric oxide or reactive oxygen species, and serves a protective function during oxidative stress . Cytoglobin’s molecular roles include nitric oxide dioxygenase and lipid peroxidase activities .

Cytoglobin is expressed in all tissues, with the highest levels found in the heart, stomach, bladder, and small intestine . Its expression increases in response to various stress conditions, including hypoxia, oxidative stress, and fibrotic stimulation . When overexpressed, cytoglobin provides cytoprotection against these factors .

Cytoglobin has been implicated in various pathological conditions. It is upregulated in fibrosis and neurodegenerative disorders and downregulated in multiple cancer types . Cytoglobin has shown potential as a tumor suppressor, inhibiting cancer cell growth in vitro . Additionally, CYGB expression can be used as a specific marker to distinguish hepatic stellate cells from portal myofibroblasts in the damaged human liver .