描述:
Fas Ligand (FasL), also known as CD178, CD95L, or TNFSF6, is a 40 kDa type II transmembrane
member of the TNF superfamily of proteins. Its ability to induce apoptosis in target cells plays
an important role in the development, homeostasis, and function of the immune system.
Mature human Fas Ligand consists of a 179 amino acid (aa) extracellular domain (ECD), a 22
aa transmembrane segment, and a 80 aa cytoplasmic domain. Within the ECD, human Fas
Ligand shares 81% and 78% aa sequence identity with mouse and rat Fas Ligand, respectively.
Both mouse and human Fas Ligand are active on mouse and human cells. Fas Ligand is
expressed on the cell surface as a nondisulfidelinked homotrimer on activated CD4+ Th1
cells, CD8+ cytotoxic T cells, and NK cells. Fas Ligand binding to Fas/CD95 on an adjacent cell
triggers apoptosis in the Fas-expressing cell . Fas Ligand also binds DcR3 which is a soluble
decoy receptor that interferes with Fas Ligandinduced apoptosis. Fas Ligand can be released
from the cell surface by metalloproteinases as a 26 kDa soluble molecule which remains
trimeric. Shed Fas Ligand retains the ability to bind Fas, although its ability to trigger apoptosis
is dramatically reduced. In the absence of TGF-β, however, Fas Ligand/Fas interactions instead
promote neutrophilmediated inflammatory responses. Fas Ligand itself transmits reverse
signals that costimulate the proliferation of freshly antigen-stimulated T cells. Fas Ligand
induced apoptosis plays a central role in the development of immune tolerance and the
maintance of immune privileged sites. This function is exploited by tumor cells which evade
immune surveillance by upregulating Fas Ligand to kill tumor infiltrating lymphocytes. In gld
mice, a Fas Ligand point mutation is the cause of severe lymphoproliferation and systemic
autoimmunity.
原厂资料:
Fas Ligand (FasL), also known as CD178, CD95L, or TNFSF6, is a 40 kDa type II transmembrane
member of the TNF superfamily of proteins. Its ability to induce apoptosis in target cells plays
an important role in the development, homeostasis, and function of the immune system.
Mature human Fas Ligand consists of a 179 amino acid (aa) extracellular domain (ECD), a 22
aa transmembrane segment, and a 80 aa cytoplasmic domain. Within the ECD, human Fas
Ligand shares 81% and 78% aa sequence identity with mouse and rat Fas Ligand, respectively.
Both mouse and human Fas Ligand are active on mouse and human cells. Fas Ligand is
expressed on the cell surface as a nondisulfidelinked homotrimer on activated CD4+ Th1
cells, CD8+ cytotoxic T cells, and NK cells. Fas Ligand binding to Fas/CD95 on an adjacent cell
triggers apoptosis in the Fas-expressing cell . Fas Ligand also binds DcR3 which is a soluble
decoy receptor that interferes with Fas Ligandinduced apoptosis. Fas Ligand can be released
from the cell surface by metalloproteinases as a 26 kDa soluble molecule which remains
trimeric. Shed Fas Ligand retains the ability to bind Fas, although its ability to trigger apoptosis
is dramatically reduced. In the absence of TGF-β, however, Fas Ligand/Fas interactions instead
promote neutrophilmediated inflammatory responses. Fas Ligand itself transmits reverse
signals that costimulate the proliferation of freshly antigen-stimulated T cells. Fas Ligand
induced apoptosis plays a central role in the development of immune tolerance and the
maintance of immune privileged sites. This function is exploited by tumor cells which evade
immune surveillance by upregulating Fas Ligand to kill tumor infiltrating lymphocytes. In gld
mice, a Fas Ligand point mutation is the cause of severe lymphoproliferation and systemic
autoimmunity.