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Recombinant Human Sonic Hedgehog is part of a small group of secreted proteins that are vital for development in both vertebrates and invertebrates. 3 mammalian hedgehog genes (sonic, desert, Indian) share about 60% homology. The Human Sonic Hedgehog is 99% homologous to the mouse gene. Sonic HedgeHog helps in guiding the early embryo. It has been associated as the major inductive signal in patterning of the ventral neural tube, the anterior-posterior limb axis, and the ventral somites. Sonic HedgeHog binds to the patched receptor, which association with smoothened, to activate the transcription of target genes. In the absence of sonic HedgeHog, patched receptor represses the constitutive signaling activity of smoothened. Sonic HedgeHog also regulates another factor, the gli oncogene. Sonic HedgeHog intercellular signal is necessary for a various patterning events during development: signal produced by the notochord that induces ventral cell fate in the neural tube and somites, and the polarizing signal for patterning of the anterior-posterior axis of the developing limb bud. Sonic HedgeHog exhibits both floor plate- and motor neuron-inducing activity. Mutations in a long-range Sonic HedgeHog enhancer located in an intron of the limb region 1 gene result in preaxial polydactyly.

Serine/threonine/tyrosine-interacting protein (STYX) is a member of the protein-tyrosine phosphatase family. STYX contains a Gly residue instead of a conserved Cys residue in the dsPTPase catalytic loop which makes it catalytically inactive as a phosphatase. On the other hand, the binding pocket is adequately preserved to bind phosphorylated substrates, and may protect them from phosphatases. STYX may have a role in spermiogenesis. STYX is a possible pseudophosphatase.

Calcium/Calmodulin Dependent Protein Kinase II Inhibitor 1 (CAMK2N1), which interacts with CAMK2B, is a part of the CAMK2N family. CAMK2N1 is also interacts with CAMK2A in a way which requires CAMK2A activation by Ca2+. CAMK2N1 is potent and specific inhibitor of CaM-kinase II (CAMK2).

L-Selectin belongs to a family of divalent cation-dependent carbohydrate-binding glycoproteins or adhesion molecules. The L-Selectin molecule is composed of various domains: one homologous to lectins, one to epidermal growth factor, and two to the consensus repeat units found in C3/C4 binding proteins.
L-selectin is expressed constitutively on lymphocytes, monocytes and granulocytes and interacts specifically with carbohydrate groups on activated endothelial cells. L-Selectin may be shed by proteolytic cleavage and circulating levels in biological fluids may be used as an indicator of various pathological conditions. L-Selectin is cleaved by ADAM17.
L-selectin works as a "homing receptor" for leukocytes to enter secondary lymphoid tissues via the high endothelial venules. Ligands present on endothelial cells will attach to leukocytes expressing L-selectin, which causes the leukocytes to become localized at that juncture. The receptor is also located on the cell surfaces of "naive" T cells, which have not yet encountered their particular antigen. This surface expression is lost following the cells activation.

TSG101 is a member of apparently inactive homologs of ubiquitin-conjugating enzymes. TSG101 contains a coiled-coil domain that interacts with stathmin, a cytosolic phosphoprotein implicated in tumorigenesis. TSG101 is involved in cell growth and differentiation and acts as a negative growth regulator. TSG101 in vitro steady-state expression is important for maintenance of genomic stability and cell cycle regulation. TSG101 mutations and alternative splicing occur in high rate in breast cancer and implicate that defects occur during breast cancer tumorigenesis and/or progression. TSG101 is a factor of the ESCRT-I complex, a monitor of vesicular trafficking process. TSG101 binds to ubiquitinated cargo proteins and is needed for the sorting of endocytic ubiquitinated cargos into multivesicular bodies. TSG101 is needed for completion of cytokinesis and is involved in cell growth and differentiation.

GDF8 is a member of the bone morphogenetic protein (BMP) family and the TGF-beta superfamily. This group of proteins is characterized by a polybasic proteolytic processing site which is cleaved to produce a mature protein containing seven conserved cysteine residues. The members of this family are regulators of cell growth and differentiation in both embryonic and adult tissues. This gene is thought to encode a secreted protein which negatively regulates skeletal muscle growth.

Tumor necrosis factor receptor superfamily member 8 (TNFRSF8) is a receptor for TNFSF8/CD30L. TNFRSF8 has a role in the regulation of cellular growth and transformation of activated lymphoblasts. In addition, the TNFRSF8 protein regulates gene expression via activation of NF-kappa-B. TNFRSF8 being a regulator of apoptosis, induces cell death or proliferation, depending on the cell type.

Uromodulin is the most abundant protein in normal urine. Its secretion in urine follows proteolytic cleavage of the ectodomain of its glycosyl phosphatidylinosital-anchored counterpart that is situated on the luminal cell surface of the loop of Henle. Uromodulin plays a role as a constitutive inhibitor of calcium crystallization in renal fluids. Secretion of uromodulin in urine provides protection against urinary tract infections caused by uropathogenic bacteria. Defects in Uromodulin expression are associated with the autosomal dominant renal disorders medullary cystic kidney disease-2 (MCKD2) and familial juvenile hyperuricemic nephropathy (FJHN). These disorders are characterized by juvenile onset of hyperuricemia, gout, and progressive renal failure. While several transcript variants may exist for this gene, the full-length natures of only two have been described to date. UMOD is involved in regulating the circulating activity of cytokines as it binds to il-1, il-2 and tnf with high affinity.

Chemokine (C-C motif) ligand 21 (CCL21) is a small cytokine belonging to the CC chemokine family. This chemokine is also known as 6Ckine (because it has six conserved cysteine residues instead of the four cysteines typical to chemokines), exodus-2, and secondary lymphoid-tissue chemokine (SLC). CCL21 is expressed predominantly in the lymph nodes and, in contrast to other CC chemokines, is chemotactic for lymphocytes. The gene for CCL21 is located on human chromosome 9. CCL21 elicits its effects by binding to a cell surface chemokine receptor known as CCR7.

TIMP1 is a member of the TIMP family. TIMP1 is an inducible glycoprotein produced by various cell types. The TIMP1 glycoprotein is a natural inhibitor of the matrix metalloproteinases, which a group of peptidases involved in degradation of the extracellular matrix. TIMP1 binds in a reversible mode to MMPs, with regions in the N-terminal domain binding to the MMP substrate-binding site. On top of its inhibitory function against most of the known MMPs, TIMP1 is able to promote cell proliferation in a broad range of cell types, and may also have an anti-apoptotic role. Furthermore, TIMP1 has erthyroid-potentiating activity via translocation to the nucleus and also inhibits apoptosis in B-cells.
The TIMP1 gene is situated within intron 6 of the synapsin I gene and is transcribed in the opposite direction. TIMP1 activity is dependent on the existence of disulfide bonds.
TIMP1 transcription is extremely inducible in reaction to many cytokines and hormones.
Increased TIMP1 levels are connected with squamous cell laryngeal carcinoma. TIMP1 overexpression is linked to gastric cancer.

Lymphotoxin alpha, a member of the tumor necrosis factor family, is a cytokine produced by lymphocytes. LTA is highly inducible, secreted, and exists as homotrimeric molecule. LTA forms heterotrimers with lymphotoxin-beta which anchors lymphotoxin-alpha to the cell surface. LTA mediates a large variety of inflammatory, immunostimulatory, and antiviral responses. LTA is also involved in the formation of secondary lymphoid organs during development and plays a role in apoptosis.

Chemokine (C-X-C motif) ligand 1 (CXCL1) is a small cytokine belonging to the CXC chemokine family that was previously called GRO1 oncogene, Neutrophil-activating protein 3 (NAP-3) and melanoma growth stimulating activity, alpha (MSGA-a). It is secreted by human melanoma cells, has mitogenic properties and is implicated in melanoma pathogenesis. CXCL1 is expressed by macrophages, neutrophils and epithelial cells, and has neutrophil chemoattractant activity. CXCL1 plays a role in spinal cord development by inhibiting the migration of oligodendrocyte precursors and is involved in the processes of angiogenesis, inflammation, wound healing, and tumorigenesis. This chemokine elicits its effects by signaling through the chemokine receptor CXCR2. The gene for CXCL1 is located on human chromosome 4 amongst genes for other CXC chemokines.

IL17 is a proinflammatory cytokine produced by activated T cells. IL-17 regulates the activities of NF-kappaB and mitogen-activated protein kinases. Interleukin-17 can stimulate the expression of IL6 and cyclooxygenase-2 (PTGS2/COX-2), as well as enhance the production of nitric oxide (NO). High levels of IL-17 are associated with several chronic inflammatory diseases including rheumatoid arthritis, psoriasis and multiple sclerosis.

Interleukin-6 is a potent pro-inflammatory cytokine primarily produced by activated T cells and an assortment of other cells including endothelial cells and macrophages. IL-6 affects B and T lymphocytes and has been shown to have a role in host defense, acute phase reactions, immune responses and hematopoiesis.

Treponema pallidum is a gram-negative spirochaete bacterium and is considered to be metabolically crippled. There are at least four known subspecies: T. pallidum pallidum, T. pallidum pertenue, T. pallidum carateum and T. pallidum endemicum. The helical structure of T. pallidum pallidum allows it to move in a corkscrew motion through viscous mediums such as mucus. Treponema pallidum sub sp. pallidum has one of the smallest bacterial genomes at 1.14 million base pairs (Mb) and has limited metabolic capabilities, reflecting its adaptation through genome reduction to the rich environment of mammalian tissue.

Tp0453 is a carrier of lipids and glycolipids during outer membrane. Tp045 is hypothesized to be a new type of bacterial outer membrane protein, which reduces T.pallidum outer membrane permeability to nutrients while remaining inaccessible to antibodies. Tp0453 exhibited 100% specificity and sensitivity in reaction with syphilis patients’ sera, giving negative result with Lyme disease, relapsing-fever or leptospirosis patients’ sera.

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.

PTEN, a tumor suppressor, has been implicated in a large number of human tumors and is conserved from humans to worms. PTEN has a tensin like domain and a catalytic domain similar to that of the dual specificity protein tyrosine phosphatases. Characterization of PTEN protein showed that it is a phosphatase that acts on proteins and on 3-phosphorylated phosphoinositides, and can therefore modulate signal transduction pathways that involve lipid second messengers. In contrast to most of the protein tyrosine phosphatases, PTEN preferentially dephosphorylates phosphoinositide substrates. PTEN negatively regulates intracellular levels of phosphatidylinositol-3,4,5-trisphosphate in cells and acts as a tumor suppressor by negative regulation of AKT/PKB signaling pathway. Recent results indicate that at least part of its role is to regulate the activity of the serine/threonine kinase AKT/PKB, and thus influence cell survival signaling.

IL-18 is a proinflammatory cytokine. This cytokine can induce the IFN-gamma production of T cells. The combination of this cytokine and IL12 has been shown to inhibit IL4 dependent IgE and IgG1 production, and enhance IgG2a production of B cells. IL-18 binding protein (IL18BP) can specifically interact with this cytokine, and thus negatively regulate its biological activity.

Twisted gastrulation Protein (TSG) is a secreted, cysteine-rich protein which has a role in dorsal/ventral patterning in Drosophila and Xenopus by regulating BMP signaling. TSG functions as an agonist for BMP signaling by controlling the inhibitory actions of the BMP antagonist, Chordin/Sog, and the cleavage properties of the metalloprotease, xolloid/tolloid. TSG N-terminal domain binds BMP protein directly and displays BMP antagonist activity.

Interleukin-17A or IL17A is a cytokine, that has a crucial part in chronic & anti-microbial inflammation. Mouse, rat and human share approximately 60% resemblance is the amino acid sequence. IL17A enhances mucosal & epidermal inflammation when an infection from bacteria occurs, it causes production of chemokines, influx of neutrophils & antibacterial proteins production.

Celiac disease is an enteropathy that is characterized by intestinal lesions of variable severity. Tissue-type transglutaminase (tTG) is believed to be the predominant autoantigen for celiac disease and the corresponding autoantibodies show higher sensitivity and specificity than anti-gliadin antibodies. Highly pure recombinant human tTG is now available to replace the traditionally used tTG fraction from guinea pig.
Tissue-type transglutaminase antigens have been specifically modified for improved handling: exchange of an active site amino acid eliminates the protein cross-linking activity of the enzyme, while maintaining the native three-dimensional structure and the enzyme's secondary GTPase activity. This engineering assures reproducible properties of the antigen preparations through the absence of variable and ill-defined covalent aggregates of tTG antigen and host cell proteins.

Endothelial cells express three different vascular endothelial growth factor (VEGF) receptors, belonging to the family of receptor tyrosine kinases (RTKs). They are named VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1), VEGFR-3 (Flt-4). Their expression is almost exclusively restricted to endothelial cells, but VEGFR-1 can also be found on monocytes, dendritic cells and on trophoblast cells. The flt-1 gene was first described in 1990. The receptor contains seven immunoglobulin-like extracellular domains, a single transmembrane region and an intracellular splited tyrosine kinase domain. Compared to VEGFR-2 the Flt-1 receptor has a higher affinity for VEGF but a weaker signaling activity. VEGFR-1 thus leads not to proliferation of endothelial cells, but mediates signals for differentiation. Interestingly a naturally occuring soluble variant of VEGFR-1 (sVEGFR-1) was found in HUVE supernatants in 1996, which is generated by alternative splicing of the flt-1 mRNA. The biological functions of sVEGFR-1 still are not clear, but it seems to be an endogenous regulator of angiogenesis, binding VEGF with the same affinity as the full-length receptor.

Tubulointerstitial Nephritis Antigen Like 1 also known as TINAGL1 is similar in sequence to tubulointerstitial nephritis antigen, a secreted glycoprotein which is identified by antibodies in several types of immune-related tubulointerstitial nephritis. Three transcript variants encoding different isoforms are known for TINAGL1.