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A natural cytotoxicity receptor (NCR) NKp46 has been shown to represent a novel NK cell-specific molecule involved in human NK cell activation. The natural cytotoxicity receptors (NCRs) are a recently characterized family of Ig-like activation receptors that appear to be major triggering receptors in tumor cell recognition. The three known NCRs include NKp46 and NKp30, which are expressed on circulating NKcells, and NKp44, which is expressed only on activating NK cells. NKp46 has been implicated in NK cell-mediated lysis of several autologous tumor cells, pathogen-infected cell lines and mononuclear phagocytes infected with an intracellular bacterium. The Lysis of tumor cells by NK-cells involves recognition by NKp46 of heparan sulfate moieties of membrane heparan sulfate proteoglycans. Furthermore, NKp46 is a surface receptor involved in NK-cell cell death by apoptosis. NKp46 has two extracellular Ig-like domains followed by a ~40 residue stalk region, a type I transmembrane domain, and a short cytoplasmic tail. The extracellular Ig-like domain of NKp46 (22-255aa) is purified by FPLC gel-filtration chromatography, after refolding of the isolated inclusion bodies in a redox buffer. In addition, engagement of the antigen with the monoclonal antibody stimulates intracellular calcium levels and the synthesis of cytokines. CD59 is an NKp46 coreceptor (by physical association) together they activate cytotoxicity of human NK-cells, their engagement results in tyrosine phosphorylation of CD3-zeta chains associated with NKp46. Reduced cell surface expression of NKp46 and other NK-cell receptors is linked to the impaired NK-cell cytolytic function in viremic HIV-1 infection.

Zinc-alpha-2-glycoprotein (AZGP1) protein stimulates lipid degradation in adipocytes and causes the massive fat losses linked with various advanced cancers. AZGP1 may bind polyunsaturated fatty acids.

Stratifin is part of the 14-3-3 family. The 14-3-3 family of proteins plays an important regulatory function in signal transduction, checkpoint control, apoptotic and nutrient-sensing pathways. 14-3-3 proteins are highly conserved and ubiquitously expressed. There are 7 isoforms, beta, gamma, epsilon, sigma, zeta, tau and eta that have been identified in mammals. Stratifin is an epithelial cell marker that functions as a tumor suppressor whose expression can be down regulated via methylation. Failure of Stratifin expression results in a defective G2/M phase checkpoint and results in epithelial and non-epithelial tumorigenesis.

Profilin1 (PFN1) is a ubiquitous actin monomer-binding protein which is a member of the profilin family. PFN1 significantly boosts skin wound healing in-vitro and in-vivo which may be mediated by purinergic receptors. PFN1 is also active in endothelial cell migration and vessel sprouting. PFN1 is thought to control actin polymerization in response to extracellular signals. PFN1 binds to actin and affects the formation of the cytoskeleton. In addition, PFN1 has an important role in the regulation of epithelial cell-cell adhesion. At high concentrations, profilin averts the polymerization of actin, while at low concentrations it enhances the polymerization. PFN1 gene deletion is linked to Miller-Dieker syndrome.

Guanine nucleotide-binding protein G(z) subunit alpha (GNAZ) belongs to the G protein subfamily which mediates signal transduction in pertussis toxin-insensitive systems. GNAZ has a role in maintaining the ionic balance of perilymphatic and endolymphatic cochlear fluids. G proteins are involved as modulators or transducers in a variety of transmembrane signaling systems.

Gametocyte Specific Factor 1 (GTSF1) is a member of the UPF0224 (FAM112) family and contains 1 CHHC-type zinc finger. A key paralog of the GTSF1 gene is GTSF1L.

MANF is a 20kDa protein which belongs to the ARMET family. MANF was originally known as an arginine-rich region protein which was extremely mutated in a large number of tumors. MANF Expression is induced during ER stress, signifying that MANF takes part in protein quality control during ER stress.

RGS19 is a member of RGS (regulator of G protein signaling) family and negatively regulates G protein coupled receptor signaling. RGS19 protein specifically cooperates with heterotrimeric GTP-binding protein G alpha i3 (GAI3).

LGALS8 is a prostate-specific antigen that is solely overexpressed in malignant tumors and thus is a supplementary specific identifier of malignancies. LGALS8 is part of the galectin gene family which facilitates both cell-cell and cell matrix interactions in a method parallel to the selectin subgroup of C-type lectins.

Recombinant Human Holo Transferrin is an iron-delivery signaling protein which functions in the delivery of Fe³⁺ iron to cells using transferrin receptor-1 (TfR1/CD71).
Holo-transferrin binds TfR1, undergoes receptor-mediated endocytosis and the iron is released intracellularly. Transferrin Human Recombinant is crucial for brain and the nervous system, neuronal mitochondrial metabolism, neurotransmitter synthesis, oligodendrocyte myelination and synaptic activity. Recombinant holo-transferrin can be used in cell therapy, stem-cell expansion, CHO production, or drug-delivery platforms.

Meteorin (METRN) is involved in both glial cell differentiation and axonal network formation during neurogenesis. METRN promotes astrocyte differentiation and transforms cerebellar astrocytes into radial glia. Moreover, the METRN protein stimulates axonal extension in small and intermediate neurons of sensory ganglia by activating nearby satellite glia.

GAP43 is a phosphoprotein of the presynaptic membrane that takes part in synaptic reorganization and neural development. GAP43 is found in large quantities in neuronal growth cones all through the development and axonal regeneration. Additionally, GAP43 is involved in specific regions of the normal adult nervous system and has a vital part in the conservation mechanism of long-term potentiation (LTP).

Members of the Rho (or ARH) protein family and other Ras-related small GTP-binding proteins are involved in various cellular procedures, such as cell cytoskeletal organization, secretion, proliferation, and signaling. The GTPBPs are active only in the GTP-bound state. At least 3 types of proteins firmly regulate cycling between the GTP-bound and GDP-bound states: GDP-dissociation inhibitors (GDIs), GTPase-activating proteins (GAPs) and guanine nucleotide-releasing factors (GRFs). ARHGDIB and the other GDIs lower the level of GDP dissociation from Ras-like GTPases.

LYVE1 is a selective marker of the lymphatic endothelium & a surface endocytic receptor for both soluble and immobilized hyaluronan, LYVE1 is an extracellular glycosaminoglycan that plays a role in cell adhesion and migration. LYVE1 functions in lympathic hyaluronan transport and is involved in tumor metastasis. Recombinant human LYVE1 was expressed in and purified by conventional chromatography techniques. The normal adult human choroid is endowed with a significant number of LYVE-1 positive macrophages. LYVE-1 is expressed in a reticulum cell neoplasm in an axillary lymph node. This reticulum cell sarcoma is a lymphatic sinus lining cell sarcoma which might represent another subtype of reticulum cell sarcomas.
LYVE-1 immunohistochemistry is a functional method for detecting lymphatics invaded by cancer cells, and detailed examination of the submucosa around the tumor is important for predicting LN metastasis.

GMFG is a hematopoietic-specific protein that mediates the pluripotentiality and lineage commitment of human hematopoietic stem cells. Glia maturation factor gamma is a cytokine-responsive protein in EPO-induced and G-CSF-induced hematopoietic lineage development. Glia maturation factor also acts as a Nerve Growth Factor in nervous system development, angiogenesis and immune function. GMFG possesses hematopoietic tissue-specific gene expression, a promoter concentrated with high-score hematopoiesis-specific transcription factors, and molecular coevolution with a rudimentary blood/immune system.

GCSF is a cytokine that controls the production, differentiation, and function of granulocytes. The active protein is found extracellularly. Three transcript variants encoding three different isoforms have been found for the GCSF gene. Granulocyte/macrophage colony-stimulating factors are cytokines that act in hematopoiesis by controlling the production, differentiation, and function of 2 related white cell populations of the blood, the granulocytes and the monocytes-macrophages. This csf induces granulocytes.

Mycobacterium antigen ESAT6 has been isolated from low molecular weight fractions of the shot-term-culture filtrate (ST-CF) and it can easily be detected in tuberculosis patients. The export of ESAT-6 which is a potent T-cell antigen, and related proteins requires a dedicated secretory apparatus that is encoded by a group of genes, several of which also code for proteins that are recognized strongly by T cells. The ESAT-6 systems can consequently be considered as immunogenicity islands and there is mounting evidence that the equivalent genes are subject to selective pressure imposed by the immune system of the host. This antigen includes many epitopes detectable in the serum of most patients with tuberculosis (more than 90%). By the attempts to obtain the vaccine on the basis of ESAT-6 it was demonstrated that the optimization of adjuvant is very important when using the combination of dioctadecylammonium bromide and monophosphoryllipide. ESAT-6 is very potential as diagnostic for differentiation between the mycobacterial infection and BCG vaccination. The main topic in ESAT-6 using is in antibody production and in test-systems for tuberculosis elaboration. Early secretory antigen 6 (ESAT6) and cell filtrate protein 10 (CFP10) are 2 antigens secreted as a complex by the replicating Mycobacterium tuberculosis complex (MTC).

SPARC, an acronym for “secreted protein, acidic and rich in cysteine”, is also known as osteonectin or BM-40. It is the founding member of a family of secreted matricellular proteins with similar domain structure. The 303 amino acid, 43 kDa protein contains a 17 aa signal sequence, an N-terminal acidic region that binds calcium, a follistatin domain containing Kazal-like sequences, and a C-terminal extracellular calcium (EC) binding domain with two EF-hand motifs. SPARC is produced by fibroblasts, capillary endothelial cells, platelets and macrophages, especially in areas of tissue morphogenesis and remodeling. SPARC shows context-specific effects, but generally inhibits adhesion, spreading and proliferation, and promotes collagen matrix formation. For endothelial cells, SPARC disrupts focal adhesions and binds and sequesters PDGF and VEGF. SPARC is abundantly expressed in bone, where it promotes osteoblast differentiation and inhibits adipogenesis.

Listeriolysin O (aka LLO) is a hemolysin produced by Listeria monocytogenes bacteria, the pathogen responsible for causing listeriosis. The toxin may be regarded as a virulence factor, since it is crucial for the virulence of L. monocytogenes. LLO is a single polypeptide protein encoded by the hlyA gene and composed of 529 residues. LLO is a thiol-activated cholesterol-dependent pore forming toxin protein; therefore, it is activated by reducing agents and inhibited by oxidizing agents. Still, LLO differs from other thiol-activated toxins, as its cytolytic activity is maximized at a pH of 5.5. Inside the acidic phagosomes (average pH ~ 5.9) of cells that have phagocytosed L. monocytogenes, LLO is selectively activated by maximizing activity at a pH of 5.5. Following the phagosome lysis by LLO, the bacterium breaks out into the cytosol, where it is able to grow intracellularly, and the toxin has reduced activity in the more basic cytosol. Thus, LLO permits L. monocytogenes to break out from the phagosomes into the cytosol without harming the plasma membrane of the infected cell, which allows the bacteria to live intracellularly, where they are sheltered from extracellular immune system factors such as the complement system and antibodies. LLO also brings about dephosphorylation of histone H3 and deacetylation of histone H4 in the early phases of infection, before entry of L. monocytogenes into the host cell. The pore-forming activity is not implicated in causing the histone modifications. The modifications of the histones affect the down regulation of genes encoding proteins involved in the inflammatory response. Therefore, LLO may be significant in subverting the host immune response to L. monocytogenes. At its NH2-terminus it possesses a 25 residues long typical signal sequence excited during the secretion process. Moreover, in its NH2-terminus there is also a 19 amino acids PEST- like sequence that may target this toxin for degradation. The PEST-like sequence found in LLO and is considered crucial for virulence, given that mutants lacking the sequence lysed the host cell. Nevertheless, contrary to PEST's supposed role in protein degradation, evidence implies that the PEST-like sequence may control LLO production in the cytosol rather than increase degradation of LLO.

PPIases catalyze the cis-trans isomerization of proline imidic peptide bonds in oligopeptides and accelerate the folding of proteins. Cyclophilin-A is a cyclosporin binding-protein and may play a role in cyclosporin A-mediated immunosuppression. Cyclophilin-A can also interact with several HIV proteins, including p55 gag, Vpr, and capsid protein, and has been shown to be necessary for the formation of infectious HIV virions. Multiple pseudogenes that map to different chromosomes have been reported.

Cyclophilin B (also known as PPIB, peptidylpropyl isomerase B) is a cyclosporine-binding protein and is mainly located within the endoplasmic reticulum. It is associated with the secretory pathway and released in biological fluids. This protein can bind to cells derived from T- and B-lymphocytes, and may regulate cyclosporine A-mediated immunosuppression.

GDF15 is part of the TGF-Beta superfamily that is involved in regulating inflammatory and apoptotic pathways in injured tissues and throughout disease processes. GDF15 is most abundant in the liver. Its expression in liver can be considerably up-regulated in during injury of organs such as liver, kidney, heart and lung. GDF-15 promotes proliferation or growth arrest and differentiation due to differences in cellular differentiation. GDF15 prevents apoptosis in cerebellar granule neurons by activating Akt and inhibiting endogenously active ERK. GDF15 is a novel autocrine/endocrine factor that antagonizes the hypertrophic response and loss of ventricular performance.