Other Proteins

The cluster of differentiation (CD) system is commonly used as cell markers in immunophynotyping. Different kinds of cells in the immune system can be identified through the surface CD molecules which associating with the immune function of the cell. There are more than 320 CD unique clusters and subclusters have been identified. Some of the CD molecules serve as receptors or ligands important to the cell through initiating a signal cascade which then alter the behavior of the cell. Some CD proteins do not take part in cell signal process but have other functions such as cell adhesion. CD74, also known as HLA class2 histocompatibility antigen gamma chain and HLA-DR antigens-associated invariant chain, is a polypeptide involved in the formation and transport of MHC class2 protein. CD74 is expressed by B cells, macrophages, and Reed-Sternberg cells. When MHC class 2 protein was in the rough ER, its peptide-binding cleft was blocked by CD74 to prevent it from interacting with the endogeno

The cluster of differentiation (CD) system is commonly used as cell markers in immunophynotyping. Different kinds of cells in the immune system can be identified through the surface CD molecules which associating with the immune function of the cell. There are more than 320 CD unique clusters and subclusters have been identified. Some of the CD molecules serve as receptors or ligands important to the cell through initiating a signal cascade which then alter the behavior of the cell. Some CD proteins do not take part in cell signal process but have other functions such as cell adhesion. CD120a (cluste of differentiation 120a), also known as TNFR1 / TNFRSF1A, is a member of CD family, tumor necrosis factor receptor superfamily. CD120a is one of the most primary receptors for the tumor necrosis factor-alpha. It has been shown to be localized to both plasma membrane lipid rafts and the trans golgi complex with the help of the death domain (DD). CD120a can activate the transcription factor

The insulin-like growth factor-1 receptor (IGF1R) is a transmembrane tyrosine kinase involved in several biological processes including cell proliferation, differentiation, DNA repair, and cell survival. This a disulfide-linked heterotetrameric transmembrane protein consisting of two α and two β subunits, and among which, the α subunit is extracellular while the β subunit has an extracellular domain, a transmembrane domain and a cytoplasmic tyrosine kinase domain. The IGF-I receptor is highly expressed in all cell types and tissues. Essentially all of the biological activities of IGF-I and II have been shown to be mediated via IGF-I R. IGF1R is an important signaling molecule in cancer cells and plays an essential role in the establishment and maintenance of the transformed phenotype. Inhibition of IGF1R signaling thus appears to be a promising strategy to interfere with the growth and survival of cancer cells, is now an attractive anti-cancer treatment target.

As a monomeric immunoglobulin that is predominately involved in the secondary antibody response and the only isotype that can pass through the human placenta, Immunoglobulin G (IgG) is synthesized and secreted by plasma B cells, and constitutes 75% of serum immunoglobulins in humans. IgG antibodies protect the body against the pathogens by agglutination and immobilization, complement activation, toxin neutralization, as well as the antibody-dependent cell-mediated cytotoxicity (ADCC). IgG tetramer contains two heavy chains (50 kDa ) and two light chains (25 kDa) linked by disulfide bonds, that is the two identical halves form the Y-like shape. IgG is digested by pepsin proteolysis into Fab fragment (antigen-binding fragment) and Fc fragment ("crystallizable" fragment). IgG1 is most abundant in serum among the four IgG subclasses (IgG1, 2, 3 and 4) and binds to Fc receptors (FcγR ) on phagocytic cells with high affinity. Fc fragment is demonstrated to mediate phagocytosis, trigger infla

Calnexin/CANX is a single-pass type I membrane protein which belongs to the calreticulin family. It consists of a large N-terminal calcium-binding lumenal domain, a single transmembrane helix and a short (90 residues), acidic cytoplasmic tail. The function of calnexin is to retain unfolded or unassembled N-linked glycoproteins in the endoplasmic reticulum. Calnexin is a calcium-binding protein that interacts briefly with newly synthesized glycoproteins in the endoplasmic reticulum. Calnexin may act in assisting protein assembly and/or in the retention within the ER of unassembled protein subunits. Calnexin seems to play a major role in the quality control apparatus of the ER by the retention of incorrectly folded proteins. Calnexin dwindles with aging and might contribute to a cytoprotection in an array of human age-related diseases.

Functions as a sorting receptor in the Golgi compartment and as a clearance receptor on the cell surface. Required for protein transport from the Golgi apparatus to the lysosomes by a pathway that is independent of the mannose-6-phosphate receptor (M6PR). Lysosomal proteins bind specifically to the receptor in the Golgi apparatus and the resulting receptor-ligand complex is transported to an acidic prelysosomal compartment where the low pH mediates the dissociation of the complex. The receptor is then recycled back to the Golgi for another round of trafficking through its binding to the retromer. Also required for protein transport from the Golgi apparatus to the endosomes. Promotes neuronal apoptosis by mediating endocytosis of the proapoptotic precursor forms of BDNF (proBDNF) and NGFB (proNGFB). Also acts as a receptor for neurotensin. May promote mineralization of the extracellular matrix during osteogenic differentiation by scavenging extracellular LPL. Probably required in adipoc

Biglycan is a 200-350 kD proteoglycan consisting of a 45 kD core protein and two chrondroitin/dermatan sulfate glycosaminoglycan chains. Biglycan binds to TGF-?. It also binds to collagen type I in low ionic strength (less than 3 mM phosphate) buffer. At higher ionic strengths, Biglycan does not bind to collagen type I. It enhances the inhibition effect of TGF-? on osteoclast proliferation at a concentration of 4-20 mg/ml. It also prevents the attachment of CHO cells to fibronectin, with a 50% inhibition at 17-21 mg/ml.

Trefoil Factor 3 (TFF3), also known as Intestinal Trefoil Factor (ITF) and P1.B, is one of three structurally related secreted proteins that contain trefoil domains. These domains adopt a three-leaved conformation held together by conserved intrachain disulfide bonds. TFF3 is an approximately 7 kDa peptide that plays an important role in epithelial regeneration and wound healing. It can form disulfide-linked dimers or associate into disulfide-linked complexes with the intestinal mucous proteins FCGBP and MUC-2. TFF3 is expressed by epithelial goblet cells in the respiratory tract, biliary and breast ducts, small and large intestine, and cardia of the stomach. Following secretion, TFF3 can be retained in the overlying mucous layer. TFF3 is also expressed by chondrocytes during bone development. Mature human TFF3 shares 76% amino acid sequence identity with mouse and rat TFF3. TFF3 is up-regulated in response to a range of gastrointestinal epithelial disruptions. It promotes epithelial w

The molecular features at the IL19 locus may modestly alter the establishment of HIV-1 infection. Interleukin (IL) 19, IL-20, and IL-24 belong to the IL-10 cytokine family and have been identified to play a role in the regulation of epidermal functions and inflammation. The expression of IL19 in biopsies of patients with active ulcerative colitis was increased compared with patients with quiescent ulcerative colitis and that colitis was attenuated in IL-19-deficient mice. The disruption of the epithelial barrier with dextran sodium sulfate leads to increased IL-19 expression. Attenuated colitis in IL-19-deficient animals was associated with reduced numbers of IL-6-producing macrophages in the inflamed colonic lamina propria. Microbial-driven expression of IL-19 by intestinal macrophages may contribute to the pathogenesis of inflammatory bowel disease.