APO-1/Fas gene: Structural and functional characteristics in systemic lupus erythematosus and other autoimmune diseases

Systemic lupus erythematosus (SLE) is an autoimmune disorder affecting multiple organ systems. It is characterized by the presence of autoantibodies reactive against various self-antigens. Susceptibility to SLE is found to be associated with many major histocompatibility complex (MHC) and non-MHC genes, one of which is APO-1/Fas gene, which is present on chromosome 10 in humans. The APO-1/Fas promoter contains consensus sequences for binding of several transcription factors that affect the intensity of Fas expression in cells. The mutations in the APO-1/Fas promoter are associated with risk and severity in various autoimmune diseases and other malignancies. The APO-1/Fas receptor is expressed by many cell types. Two forms of APO-1/Fas protein that are involved in regulation of apoptosis have been identified. Fas receptor-mediated apoptosis plays a physiological and pathological role in killing of infected cell targets. In this review, we have focused on APO-1/Fas gene structure, promoter variants and its association with SLE and other autoimmune diseases. Functional aspects of Fas receptor in apoptosis are also discussed.