FAS [Alf2.1]

GWB-83335C

IgG1

Human

FAS

1 mg/ml

15mM Sodium Azide; Constituents: 1% BSA 0. 01M PBS. pH 7. 4

Plasma membrane Homeostasis of multicellular organisms is controlled not only by the proliferation and differentiation of cells but also by cell death. The death of cells during embryogenesis endocrine-dependent tissue atrophy metamorphosis a variety of pathologic conditions and normal tissue turnover is called programmed cell death (PCD). Most PCD proceeds by apoptosis a process that includes condensation and segmentation of nuclei condensation and fragmentation of the cytoplasm and often extensive fragmentation of chromosomal DNA into nucleosome units. Many cells can be activated to undergo apoptosis following the interaction of selected ligands with cell surface receptors. The most well-studied receptors are CD95/Fas/Apo1 (apoptosis inducing protein 1) and tumor necrosis factor receptor 1 (TNFR1). Apoptosis mediated by either of these receptors results in activation of a family of cysteine proteases known as caspases. However Fas-mediated death occurs much more rapidly than that triggered by the TNFR1. The action of Fas is mediated via FADD (Fas- associated death domain)/MORT1 an adapter protein that has a death domain at its C-terminus and binds to the cytoplasmic death domain of Fas. Human CD95/Fas/Apo-1 antigen is a single transmembrane glycoprotein receptor (325 amino acids 45-48 kDa). An integral membrane protein has been identified as the Fas ligand (Fas ligand FasL CD95L). FasL is a type II transmembrane glycoprotein and is a member of the TNF family which includes TNFalpha alpha- and beta-chains of lymphotoxin (LT) CD40 ligand and CD30 ligand. The amino acid sequences of human and murine FasL are 76. 9% identical and they are not species-specific. Membrane bound FasL (mFasL) is a 40 kDa protein while the active soluble form of FasL (sFasL) was identified as a 26 kDa protein in the supernatant of activated peripheral T cells and cultured cells transfected with the full-length FasL DNA. FasL has four potential N-glycosylation sites which appear to be variably used. Consequently the apparent MW of FasL may vary per glycosylation and breakdown patterns in certain preparations. Engagement of Fas by its ligand results in the rapid induction of PCD in susceptible cells. This process bypasses the usual long sequence of signaling enzymes and immediately activates preexisting caspases. FasL is expressed on activated T cells whereas Fas is expressed on various types of cells. The cellular pathways that control apoptosis are critical to the maturation selection and survival of lymphocytes. Apoptosis or cell suicide is the physiological mode of lymphoid cell death in circumstances like negative selection of T cells in the thymus ligation of CD4 and CD3 in mature T cells downregulation of the immune response clonal deletion of B cells by antigen death of killer cell targets cytokine-mediated killing and tumor regression. Fas is also expressed on a number of lymphoma cell lines on Epstein-Barr virus-transformed B lymphoblasts and on a proportion of activated B and T cells. The production of excess soluble Fas protein would prevent cells from undergoing Fas ligand induced apoptosis and thereby permit tumor cells to escape immunosurveillance. The activation of mature T cells with phorbol myristic acetate (PMA) and ionomycin concanavalin A (Con A) or anti-CD3 induces FasL gene expression. Herpes Simplex virus type 2 (HSV-2) but not HSV-1 potentially inhibits FasL surface expresssion in infected cells and thereby suppresses FasL-mediated cell death. Antibodies reacting specifically with Fas ligand are useful tools in the study of the intracellular pathways leading from membrane receptor engagement to apoptotic cell death the tissue distribution and developmental expression pattern of Fas ligand and its essential role during mammalian development especially in immune system homeostasis.

Binds DAXX. Interacts with HIPK3. Part of a complex containing HIPK3 and FADD (By similarity). Binds RIPK1 and FAIM2. Interacts with BRE and FEM1B.

Isoform 2: Secreted.

Isoform 4: Secreted.

Isoform 6: Secreted.

Contains a death domain involved in the binding of FADD and maybe to other cytosolic adapter proteins.

Contains 1 death domain.