Transmembrane glycoproteins

T-cell receptors (TCR) are heterodimeric transmembrane glycoproteins found exclusively in T cells, with extracellular domains that closely resemble antibody Fab structures. Each of the TCR a and p chains forms half of an extracellular antigen-binding domain, and in addition has one transmembrane... 

NGF binds to the transmembrane receptor tyrosine kinase (trk, or pl40trk), now referred to as TrkA. BDNF binds to TrkB, whereas NT-3 can bind to all three Trk (A,B,C) receptors, with a preference to TrkC, and NT-4/ 5 can bind both TrkA and TrkB. Furthermore, all neurotrophins also bind with equal affnity to a 75 kD transmembrane glycoprotein, p75NTR (also referred to... 

Lu J, Sista P, Giguel F, Greenberg M, Kuritzkes DR (2004) Relative replicative fitness of human immunodeficiency virus type 1 mutants resistant to enfuvirtide (T-20), J Virol 78 4628 637 Lu M, Blacklow SC, Kim PS (1995) A tiimeric structural domain of the HlV-1 transmembrane glycoprotein, Nat Struct Biol 2 1075-1082... 

The anion exchange protein (band 3) is a transmembrane glycoprotein, with its carboxyl terminal end on the external surface of the membrane and its amino terminal end on the cytoplasmic surface. It is an example of a multipass membrane protein, extending across the... 

Glycophorins A, B, and C are also transmembrane glycoproteins but of the single-pass type, extending across the membrane only once. A is the major gly-cophorin, is made up of 131 amino acids, and is heavily glycosylated (about 60% of its mass). Its amino terminal end, which contains 16 oligosaccharide chains (15 of which are O-glycans), extrudes out from the surface of... 

Chemokines are small chemotactic cytokines that act as important messenger molecules between cells of the immune system. Chemokines produce their effects by activating a family of G-protein-coupled receptors. Chemokine receptors are all seven-transmembrane glycoproteins that are structurally related. They may be characterized into those that bind to specific ligands, or those that bind several chemokine ligands. There are also virally encoded (viral) chemokine receptors that represent shared receptors that have been transduced into the viral genome during evolutionary history (Premack and SchaU 1996). 

Additional genes and protein receptors are believed to be important in colorectal tumorigenesis. Cyclooxygenase 2 (COX-2), which is induced in colorectal cancer cells, influences apoptosis and other cellular functions in colon cells, and overexpression of the epidermal growth factor receptor (EGFR), a transmembrane glycoprotein involved... 

Cadherins Transmembrane glycoproteins (352) promoting cellcell adhesion (353,354) linked to integrins (355) and via catenins to muscle action (356)... 

Some cytokine receptors are composed of a single transmembrane polypeptide (e.g. receptors for IL-8, -9 and -10). Many contain two polypeptide components (including the IL-3, -4, and -5 receptors), and a few contain three or more polypeptide components (e.g. the IL-2 receptor contains three polypeptide chains). In some instances a single cytokine may be capable of initiating signal transduction by binding two or more distinct receptors (e.g. IL-1 has two distinct receptors (types I and II), both of which are transmembrane glycoproteins). 

The IFN-y receptor (the type II receptor) displays a more limited cellular distribution than that of the type I receptors (Table 8.5). This receptor is a transmembrane glycoprotein of molecular mass 50 kDa, which appears to function as a homodimer. The extracellular IFN-y binding region consists of approximately 200 amino acid residues folded into two homologous domains. Initiation of signal transduction also requires the presence of a second transmembrane glycoprotein known as AF-1 (accessory factor 1), which associates with the extracellular region of the receptor. 

The IL-ls induce their characteristic biological activities by binding to specific cell surface receptors present on sensitive cells. Two distinct receptors, type I and II, have been identified. Both IL-la and IL-ip can bind both receptors. The type I receptor is an 80 kDa transmembrane glycoprotein. It is a member of the IgG superfamily. This receptor is expressed predominantly on fibroblasts, keratinocytes, hepatocytes and endothelial cells. The type II receptor is a 60 kDa transmembrane glycoprotein, expressed mainly on B-lymphocytes, bone marrow cells and polymorphonuclear leukocytes. It displays a very short (29 amino acid) intracellular domain,... 

This is a 40-kDa transmembrane glycoprotein present on a variety of immune cells, such as neutrophils, B lymphocytes, platelets, eosinophils, monocytes and macrophages however, it is not expressed on NK cells. It binds monomeric IgG with very low affinity but binds well to dimers, tri-mers or aggregated IgG (Ad > 10 7 M). There are about 103 receptors per platelet, 105 per monocyte and 1-2 x 104 per neutrophil. 

Cadherins are calcium-dependent cell-cell adhesion molecules. Most cadherins are transmembrane glycoproteins consisting of five repeated extracellular... 

KW Cytokine Transmembrane Glycoprotein Signal-anchor 3D-structure ... 

A number of both pre-clinical and clinical studies have used the folate receptor or EBP as a target for immunotherapy of ovarian carcinoma [31,32]. Expression of this tumour-associated antigen by normal tissues is restricted [33]. The carcinoma-associated antigen, EGP-2, also called EpCAM, is a 38-kDA transmembrane glycoprotein, present on the majority of simple, stratified and transitional epithelia [34]. The biological function of EGP-2 has not yet been established. 

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