Fas receptor (IPR008063)

Short name: Fas_rcpt

Overlapping homologous superfamilies


Family relationships



Like all apoptotic cell death, T cell receptor (TCR)-mediated death can be divided into two phases: an inductive phase and an effector phase. The effector phase includes a sequence of steps that are common to apoptosis in many cell types, which, if not interrupted, will lead to cell death. The induction phase, which often requires the expression of new genes, consists of a set of signals that activate the effector phase. Outside the thymus, most, if not all, of the TCR-mediated apoptosis of mature T cells (sometimes referred to as activation-induced cell death (AICD)) is induced through the surface antigen Fas pathway: activation through the TCR induces expression of the Fas (CD95) ligand (FasL); the expression of FasL on either a neighbouring cell, or on the Fas-bearing cell, induces trimerisation of Fas, which then initiates a signal-transduction cascade, leading to apoptosis of the Fas-bearing cell. This commitment stage requires the activation of key death-inducing enzymes, termed caspases, which act by cleaving proteins that are essential for cell survival and proliferation [PMID: 11741599, PMID: 11391000].

Fas is also known to be essential in the death of hyperactivated peripheral CD4+ cells: in the absence of Fas, mature peripheral T cells do not die, but the activated cells continue to proliferate, producing cytokines that lead to grossly enlarged lymph nodes and spleen. Fas belongs to the tumour necrosis factor receptor (TNFR) family of cysteine-rich type I membrane receptors; its ligand (FasL) is expressed on activated lymphocytes, NK cells, platelets, certain immune-privileged cells and some tumour cells [PMID: 11741599, PMID: 11391000].

Defects in the Fas-FasL system are associated with various disease syndromes. Mice with non-functional Fas or FasL display characteristics of lympho-proliferative disorder, such as lymphadenopathy, splenomegaly, and elevated secretion of IgM and IgG. These mice also secrete anti-DNA autoantibodies and rheumatoid factor [PMID: 11391000].

GO terms

Biological Process

GO:0006915 apoptotic process
GO:0006955 immune response
GO:0007165 signal transduction

Molecular Function

GO:0004888 transmembrane signaling receptor activity

Cellular Component

GO:0016020 membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.