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C3 is central to the activation of all 3 pathways of complement activation. Initiation of each pathway generates proteolytic enzyme complexes which binds the target surface. These enzymes cleave a peptide bond in C3 releasing the anaphylatoxin C3a and activating C3b. Most of the C3 activated during complement activation never attaches to the surface due to its thioester reaction with water forming fluid phase C3b which is rapidly inactivated by factors H and I forming iC3b. Surface-bound C3b is necessary in all 3 pathways for efficient activation of C5 and formation of C5b-9 complexes that lyse the target cell membrane.

Streptavidin is a tetrameric protein secreted by Streptomyces avidinii which binds firmly to biotin. Streptavidin is widely used in molecular biology through its unique high affinity for the vitamin biotin. The dissociation constant (Kd) of the biotin-streptavidin complex is about ~10-15 mol/L. The strong affinity recognition of biotin and biotinylated molecules has made streptavidin one of the most important components in diagnostics and laboratory kits. The streptavidin/biotin system has one of the biggest free energies of association of yet observed for noncovalent binding of a protein and small ligand in aqueous solution (K_assoc = 10**14). The complexes are also extremely stable over a wide range of temperature and pH.

The IL-6 receptor complex is composed of two membrane glycoproteins: the low affinity receptor and the signaltransducing component. The soluble form of IL6R is found in the urine of healthy adult humans and the serum of HIV positive individuals, as well as in the cell culture supernatants of stimulated PBMC’s. This soluble form of IL6R results from either proteolytic cleavage from the membrane, or an isoform derived splice variant.

Eotaxin-2, also called MPIF2 & Ckb6, is a novel CC chemokine produced by activated monocytes and T lymphocytes. Eotaxin-2 selectively chemoattracts cells expressing CCR3 including eosinophils, basophils, Th2 T cells, mast cells, and certain subsets of dendritic cells. Furthermore, Eotaxin-2 inhibits the proliferation of multipotential hematopoietic progenitor cells. The mature protein, which includes C-terminal truncation, contains 78 amino acids (92 amino acids for the mouse homolog, without C-terminal truncation).
CCL24 functions as a chemotactic chemokine for resting t-lymphocytes, and eosinophils. CCL24 has lower chemotactic activity for neutrophils but none for monocytes and activated lymphocytes. CCL24 is a strong suppressor of colony formation by a multipotential hematopoietic progenitor cell line and binds to CCR3.

CD2 which is also known as E-rosette receptor, T11 and lymphocytefunction antigen-2 (LFA-2) is expressed on T cells, thymocytes, and subset of natural killer cells. Human CD2 functions as the receptor for sheep erythrocytes, human CD58 (LFA-3), and CD15s (Sialyl Lewis X). p56lck, p59fyn, CD3eta and CD3epsilon are tyrosine-phosphorylated after CD2 stimulation. CD2 plays a role in T cell activation, T- or NK-cell-mediated cytolysis, apoptosis in activated peripheral T cells, and regulation of T cell anergy.

TARC cDNA encodes a 94 amino acid precursor protein with a 23 amino acid residue signal peptide that is cleaved off to generate the 71 amino acid residue mature secreted protein. Along with CC chemokine family members, CCL-17 has approximately 24-29% amino acid sequence identity with RANTES, MIP-1a, MIP-1b, MCP-1, MCP-2, MCP-3 and I-309. TARC is expressed in thymus, and at a lower level in the lung, colon, and small intestine. TARC is in addition transiently expressed in stimulated peripheral blood mononuclear cells. Recombinant TARC has been shown to be chemotactic for T cell lines but not monocytes or neutrophils. CCL-17 was recently identified to be a specific functional ligand for CCR4, a receptor that is selectively expressed on T cells. CCL17 is one of quite a few Cys-Cys (CC) cytokine genes clustered on the q arm of chromosome 16. CCL17 shows chemotactic activity for T lymphocytes, but not monocytes or granulocytes. CCL17 binds to chemokine receptors CCR4 and CCR8. This chemokine plays important roles in T cell development in thymus as well as in trafficking and activation of mature T cells.

CD163 is an acute phase-regulated receptor which participates in the removal and endocytosis of hemoglobin/haptoglobin complexes by macrophages and thus keeps tissues from free hemoglobin-mediated oxidative damage. Furthermore, CD163 partakes in the uptake and recycling of iron, through endocytosis of hemoglobin/haptoglobin and ensuing breakdown of heme. In addition, CD163 binds hemoglobin/haptoglobin complexes in a calcium-dependent and pH-dependent way. CD163 demonstrates greater affinity for complexes of hemoglobin and multimeric haptoglobin of HP-1F phenotype than for complexes of hemoglobin and dimeric haptoglobin of HP-1S phenotype. Moreover, CD163 stimulates a cascade of intracellular signals which involves tyrosine kinase-dependent calcium recruitment, inositol triphosphate formation and secretion of IL-6 & CSF-1.

Golgi SNAP receptor complex member 2 isoform A (GOSR2) is a part of the SNARE Protein family which consists of important trafficking proteins between the endoplasmic reticulum and the Golgi and between Golgi subcompartments. GOSR2 is located near a locus implicated in familial essential hypertension, indicating that it is a potential candidate gene for this disease. GOSR2 exists as cytoplasmically oriented integral membrane proteins.

CDO1 (Cysteine dioxygenase) is a mammalian non-heme iron enzyme that initiates a number of significant metabolic pathways associated with pyruvate and several sulfurate compounds including sulfate, hypotaurine and taurine. CDO1 catalyzes the conversion of L-cysteine to cysteine sulfinic acid (cysteine sulfinate) by incorporation of dioxygen. CDO1 is a vital regulator of cellular cysteine concentrations and has an essential role in maintaining the hepatic concentration of intracellular free cysteine within a proper narrow range. CDO1 is able to alter intracellular cysteine levels and glutathione levels. CDO1 is highly expressed in the liver and placenta. On the other hand CDO1 has a low expression in heart, brain and pancreas. CDO1 can also be detected in hepatoblastoma HepG2 cells.

Interleukin-1 alpha is a proinflammatory cytokine produced by a wide variety of cell types, including macrophages, osteoblasts, monocytes and hepatocytes. Circulating levels of are normally low and only rise after stimulation by agents such as those produced byinflammation, infection or microbial endotoxins. IL-1 alpha possesses a wide variety of biological activities and exerts its effects by binding to specific cell surface receptors.

IL-16 is a pleiotropic cytokine that functions as a chemoattractant, a modulator of T cell activation, and an inhibitor of HIV replication. The signaling process of IL-16 is mediated by CD4. The product of this gene undergoes proteolytic processing, which is found to yield two functional proteins. IL-16 functions exclusively attributed to the secreted C-terminal peptide, while the N-terminal product may play a role in cell cycle control. Caspase 3 is reported to be involved in the proteolytic processing of this protein. Two transcript variants encoding different isoforms have been found for this gene.
IL-16 stimulates a migratory response in cd4+ lymphocytes, monocytes, and eosinophils. Also induces t-lymphocyte expression of interleukin 2 receptor. ligand for cd4.

GCDH is part of the acyl-CoA dehydrogenase family. GCDH is localized in the mitochondrial matrix as a homotetramer of 45-kD subunits. GCDH catalyzes the oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA and CO(2) in the degradative pathway of L-lysine, L-hydroxylysine, and L-tryptophan metabolism. GCDH uses electron transfer flavoprotein as its electron acceptor.

Interleukin-1 ra is a member of the interleukin 1 cytokine family. This protein inhibits the activities of interleukin 1, alpha (IL1A) and interleukin 1, beta (IL1B), and modulates a variety of interleukin 1 related immune and inflammatory responses. This gene and five other closely related cytokine genes form a gene cluster spanning approximately 400 kb on chromosome 2. A polymorphism of this gene is reported to be associated with increased risk of osteoporotic fractures and gastric cancer. Four alternatively spliced transcript variants encoding distinct isoforms have been reported.

Interleukin 10 receptor, alpha subunit or CDW210A, is a part of the IL-10 receptor. This protein is encoded by the IL10RA gene in humans. IL10RA is a receptor for IL-10 (interleukin 10), it is part of the interferon receptors family. This protein is responsible for the inhibition of interferon receptors synthesis by taking part in the immunosuppressive signal of interleukin 10. Among its other roles are the insulin receptor substrate-2/PI 3-kinase/AKT pathway and phosphorylation of JAK1 and TYK2 kinases.

Core 1 Beta3-Gal-T1 also known as,C1GALT1 creates the common core 1 O-glycan structure, Gal-beta-1-3GalNAc-R, by the transfer of Gal from UDP-Gal to GalNAc-alpha-1-R. Core 1 is a precursor for lots of extended mucin-type O-glycans on cell surface and secreted glycoproteins. Studies in mice have shown that this gene takes a main role in angiogenesis, thrombopoiesis and kidney homeostasis.

BTC is a potent mitogen for retinal pigment epithelial cells and vascular smooth muscle cells. The effects of betacellulin are probably mediated by the egf receptor and other related receptors.

Regulated upon Activation, Normal T-cell Expressed, and Secreted or RANTES is an 8 kDa protein classified as a chemotactic cytokine or chemokine. It has recently been renamed CCL5. RANTES is chemotactic for T cells, eosinophils and basophils and plays an active role in recruiting leukocytes into inflammatory sites. With the help of particular cytokines (i.e. IL-2 and IFN-?) that are released by T cells, RANTES also induces the proliferation and activation of certain natural killer (NK) cells to form CHAK (CC-Chemokine-activated killer) cells. It is also a HIV-suppressive factor released from CD8+ T cells. This chemokine has been localized to chromosome 17 in humans.

Chromgranin-A is part of the neuroendocrine secretory protein family. CHGA is located in secretory vesicles of neurons and endocrine cells. Chromgranin-A is a precursor to three biologically active peptides; vasostatin, pancreastatin, and parastatin. These peptides act as autocrine or paracrine negative modulators of the neuroendocrine system. Other peptides, including chromostatin, beta-granin, WE-14 and GE-25, are also derived from the full-length protein. Chromgranin-A has numerous biological activities on some tissues and organs and exerts a large spectrum of homeostatic actions, including antifungal and antimicrobial effect, modulation of cell adhesion, and inhibition of parathyroid hormone secretion.

Endoglin is a type I membrane glycoprotein located on cell surfaces and is part of the TGF beta receptor complex.
The Endoglin protein consists of a homodimer of 180 kDA with disulfide links. Endoglin has been found on endothelial cells, activated macrophages, fibroblasts, and smooth muscle cells. Furthermore, Endoglin has been found to be part of the TGF-beta1 receptor complex. Endoglin thus may be involved in the binding of TGF-beta1, TGF-beta3, activin-A, BMP-2, and BMP-7. Beside TGF-beta signaling endoglin may have other functions. It has been postulated that endoglin is involved in the cytoskeletal organization affecting cell morphology and migration. Endoglin has a role in the development of the cardiovascular system and in vascular remodeling. Endoglin expression is regulated during heart development . Experimental mice without the endoglin gene die due to cardiovascular abnormalities.

Osteopontin is a glycoprotein that was first identified in osteoblasts and is involved in bone remodeling, immune functions in fibroblasts, macrophages, and lymphocytes during inflammation and wound healing. SPP1 binds tightly to hydroxyapatite. SPP1 forms an integral part of the mineralized matrix. SPP1 is vital to cell-matrix interaction.
Secreted Phosphoprotein-1 protects against cardiac ischemia-reperfusion injury via late preconditioning. Expression of both Ostepontin and CD44 in hepatocellular carcinoma is linked with advanced tumor stage and contributes to prognosis information. SPP1 is the most over-expressed gene in intrahepatic cholangiocarcinoma. Secreted Phosphoprotein-1 overexpression is related with interstitial lung diseases.

CCL23 (MIP-3) is a ligand for the CCR1chemokine receptor. CCL23 is one of several cytokine genes clustered on the q-arm of chromosome 17, in a locus containing several other CC chemokines. MIP-3 chemoattracts monocytes, resting T-lymphocytes and neutrophils, but not activated lymphocytes. Furthermore, it was shown that MIP-3 inhibits colony formation of bone marrow myeloid immature progenitors. MIP-3 is mainly expressed in lung and liver tissue, but can be also found in bone marrow and placenta, as well as in some cell lines of myeloid origin.
Alternative splicing of the CCL23 gene produces 2 mRNAs which encode a short (CK?8) and a long (CK?81) isoform of the MIP-3. CK?8 cDNA encodes a 120 amino acid residue precursor protein with a putative 21 a.a. residue signal peptide which is cleaved to generate a 99 a.a. residue mature CK?8 (a.a. 22-120). Further N-terminal processing of the 99 a.a. residue variant can produce a 75 a.a. residue CK?8 (a.a. 46-120) which is considerably more active than the 99 a.a. residue variant.
MIP-3 may be involved in the malignant progression of certain human cancer cells which overexpress ErbB2 through the transactivation of ErbB2 tyrosine kinase. MIP-3 may also be involved in angiogenesis via upregulation of matrix metalloproteinase MMP-2 expression.

GLUL catalyzes the synthesis of glutamine from glutamate and ammonia. Glutamine is a major source of energy and that takes part in cell proliferation, inhibition of apoptosis, and cell signaling. GLUL is expressed during early fetal stages, and has a role in maintaining body pH by removing ammonia from circulation. Mutations in GLUL gene are related with congenital glutamine deficiency.

Chemokine (C-C motif) ligand 11 (CCL11) is a small cytokine belonging to the CC chemokine family that is also known as eotaxin. CCL11 selectively recruits eosinophils by inducing their chemotaxis, and therefore, is implicated in allergic responses. The effects of CCL11 are mediated by its binding to a G-protein-linked receptor known as a chemokine receptor. Chemokine receptors for which CCL11 is a ligand include CCR2, CCR3 and CCR5. The gene for human CCL11 (scya11) is encoded on three exons and is located on chromosome 17.