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Enteropeptidase or enterokinase is an enzymeinvolved in human digestion. It is produced by cells in the duodenum wall, and is secreted from duodenum's glands, the crypts of Lieberk?hn, whenever ingested food enters the duodenum from the stomach. Enteropeptidase has the critical job of turning trypsinogen(a zymogen) to trypsin, indirectly activating a number of pancreaticdigestive enzymes.
Enteropeptidase is a serine proteaseenzyme(EC3.4.21.9). Enteropeptidase is a part of the Chymotrypsin-clan of serine proteases, and is structurally similar to these proteins.

Neuropilin 1 (Nrp1) is a transmembrane glycoprotein which functions as a co-receptor for several extracellular ligands including class III/IV semaphorins, some isoforms of vascular endothelial growth factor and transforming growth factor beta. Nrp1 binds vascular endothelial growth factor (VEGF)-A and is believed to serve as a coreceptor for kinase insert domain-containing receptor (KDR) by connecting with KDR and enhancing VEGF signaling. Nrp1 is a marker of regulatory T cells.

Type 1 cystatins are also called stefins which function as intracellular thiol protease inhibitors. Cystatin-B protein is able to form a dimer stabilized by noncovalent forces, inhibiting papain and cathepsins l, h and b. CSTB protein protects proteases leakage from lysosomes. Mutations in Stefin-B gene cause primary defects in patients with progressive myoclonic epilepsy (EPM1), a degenerative disease of the central nervous system. CSTB is overexpressed & elevated in the serum of HCC patients. Cystatin-B in vivo has a polymeric structure which is sensitive to the redox environment. Cystatin-B inhibits bone resorption by down-regulating intracellular cathepsin K activity despite increased osteoclast survival. Protein and mRNA levels of stefin B are significantly lower in atypical benign meningiomas. Stefins-A & Stefin-B which belong to the type-1 Cystatins, are up-regulated in lung tumours and thus able to counteract harmful tumour-associated proteolytic activity. Human stefin-A & Stefin-B form amyloid fibrils. Copper binding by stefin-B reduces amyloid fibril formation. A number of alternatively spliced CSTB isoforms were recognized in patients with progressive myoclonus epilepsy. Decreased CSTB activity in EPM1 pathogenesis is controled by cathepsins through increased activity of cathepsin-S & cathepsin-L.

Endothelin-2 is a Hypoxia-induced Autocrine Survival Factor for Breast Tumor Cells. The synthesis of EDN2 by human kidney carcinoma cells is decreased by EGF. EDN2 is a chemoattractant for macrophages and THP-1 monocytic cells. Chemotaxis towards EDN2 is via the MAPK pathway: p44 and p42 are phosphorylated when THP-1 cells are stimulated with EDN2. Migration to EDN2 is inhibited by hypoxia and by pertussis toxin. EDN2 leads to activation of macrophages. EDN2 shares a similar peptide sequence with chemokines and may signal via a similar receptor and MAPK-mediated pathway. Furthermore, EDN2 expression by tumors may modulate the behavior of macrophages such that activated cells accumulate in areas of hypoxia.

Chemokine (C-X-C motif) ligand 5 (CXCL5) is a small cytokine belonging to the CXC chemokine family that is also known as epithelial-derived neutrophil-activating peptide 78 (ENA-78). It is produced following stimulation of cells with the inflammatory cytokines interleukin-1 or tumor necrosis factor-alpha. Expression of CXCL5 has also been observed in eosinophils, and can be inhibited with the type II interferon IFN-?. This chemokine stimulates the chemotaxis of neutrophils possesses angiogenic properties. It elicits these effects by interacting with the cell surface chemokine receptor CXCR2. The gene for CXCL5 is encoded on four exons and is located on human chromosome 4 amongst several other CXC chemokine genes. CXCL5 has been implicated in connective tissue remodelling.

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.

TPMT, thiopurine S-methyltransferase, is a cytosolic enzyme that metabolizes thiopurine drugs via S-adenosyl-L-methionine as the S-methyl donor and S-adenosyl-L-homocysteine as a byproduct. TPMT activity exhibits autosomal codominant genetic polymorphism, and patients inheriting TPMT-deficiency are at high risk of potentially fatal hematopoietic toxicity.

Latexin enzyme is a carboxypeptidase A inhibitor that is highly expressed in the heart, prostate, ovary, kidney, pancrease, brain and colon. Latexin has no noticeable sequence resemblance with plant and parasite inhibitors, however it is related to a human putative tumor suppressor protein, TIG1. Latexin is down-regulated in the presenilin-1-deficient mouse brain, thus putatively playing a role in Alzheimer's disease.

Neurofilaments are type IV intermediate filament heteropolymers that are composed of light, medium, and heavy chains. Neurofilaments comprise the axoskeleton and functionally maintain neuronal caliber and may also have a role in intracellular transport to axons and dendrites.
NeuroFilament 160kDa is a medium neurofilament protein, which is commonly used as a biomarker of neuronal damage.

Troponin Complex is a heteromeric protein playing an important role in the regulation of skeletal and cardiac muscle contraction. It consists of three subunits, Troponin I , Troponin T and Troponin C. Each subunit is responsible for part of Troponin Complex function. E.g. Troponin I inhibits ATP-ase activity of acto-myosin. Troponin T and Troponin I are presented in cardiac muscles in different forms than in skeletal muscles. Purified subunits of rcTnI, rcTnC and rcTnT are recomplexed in vitro under appropriate conditions.

Matrix metalloproteinase-7 (MMP-7) also known as matrilysin and PUMP (EC 3.4.24.23) cleaves a number of substrates including collagen types IV and X, elastin, fibronectin, gelatin, laminin and proteoglycans. MMP-7 is closely related to the stromelysin family members but is encoded by a different gene. MMP-7 is the smallest of all the MMPs consisting of a pro-peptide domain and a catalytic domain. It lacks the hemopexin-like domain common to other members of the MMPs. MMP-7 is secreted as a 28 kDa proenzyme and can be activated in vitro by organomercurials and trypsin and in vivo by MMP-3 to a 18 kDa active MMP-7 enzyme. Once activated, MMP-7 can activate pro-MMP-1 and pro-MMP-9 but not pro-MMP-2. MMP-7 is widely expressed having been reported in elevated levels in cycling endometrium as well as in colorectal cancers and adenomas, hepatocellular carcinomas, rectal carcinomas, and approximately 50% of gliomas.

Meprin A subunit beta (MEP1B) belongs to the astacin family of zinc endopeptidases 1, 2. MEP1B is a disulfide-linked, tetrameric metalloendopeptidase in renal brush border membranes. MEP1B is highly regulated, secreted cell-surface metalloendopeptidase, which is amply expressed in the kidney and intestine.

SERPINA5 up regulates TAFI activation by inhibiting the protein C activation. SERPINA5 is a significant regulator in the equilibrium between coagulation and fibrinolysis by differentially inhibiting the activation of TAFI and of Protein-C. SERPINA5 belongs to the serpin serine proteinase inhibitor family. SERPINA5 protein inhibits plasminogen activators as well as activated protein C.
SERPINA5 is secreted in plasma & liver. SERPINA5 is involved in cell inflammation, proliferation, apoptosis, tumour cell migration, invasion, and metastasis. Moreover, SERPINA5 controls the invasive potential of renal cell carcinoma by inhibiting urinary plasminogen activator secreted by the cells. SERPINA5 participtes in regulating key serine proteases which are involved in metastatic prostate disease.

CTK-19 is a member of the keratin family. The keratins are intermediate filament proteins responsible for the structural integrity of epithelial cells and are subdivided into cytokeratins and hair keratins. The type I cytokeratins consist of acidic proteins which are arranged in pairs of heterotypic keratin chains. Unlike its related family members, this smallest known acidic cytokeratin is not paired with a basic cytokeratin in epithelial cells. It is specifically expressed in the periderm, the transiently superficial layer that envelopes the developing epidermis. The type I cytokeratins are clustered in a region of chromosome 17q12-q21.

CKMT1A is in charge of the transfer of high energy phosphate from mitochondria to the cytosolic carrier, creatine. CKMT1A is a member of the creatine kinase isoenzyme family and exists as two isoenzymes, sarcomeric MtCK and ubiquitous MtCK, encoded by separate genes. Mitochondrial creatine kinase arises in two different oligomeric forms: dimers and octamers, unlike the exclusively dimeric cytosolic creatine kinase isoenzymes. Numerous malignant cancers with poor prognosis have displayed overexpression of ubiquitous mitochondrial creatine kinase which is linked to high energy turnover and inability to remove cancer cells through apoptosis.

Interleukin-6 Signal Transducer or IL6ST is a receptor, part of the family of class 1 cytokine receptor. IL6ST binds to IL-6 through membrane-anchored or soluble IL-6R starts a connection between another complex of IL6ST and IL-6 , thus forming a homo-dimer and a signal transduction occurs.

The cytokine Macrophage migration inhibitory factor (MIF) has been identified to be secreted by the pituitary gland and the monocyte/macrophage and to play an important role in endotoxic shock. MIF has the unique property of being released from macrophages and T cells in response to physiological concentrations of glucocorticoids. The secretion of MIF is tightly regulated and decreases at high, anti-inflammatory steroid concentration.

PSMB10 is a member of the proteasome B-type family (T1B family) which is a 20S core beta subunit. The proteasome is a multicatalytic proteinase complex with an extremely ordered ring-shaped 20S core structure. This core structure is comprised of four rings of 28 non-identical subunits; two rings are composed of seven alpha subunits and two rings are composed of seven beta subunits. Proteasomes are circulated in eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. A crucial function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. PSMB10 gene expression is induced by INFg, and it replaces catalytic subunit 2 (proteasome beta 7 subunit) in the immunoproteasome.

HC Class II is consists of 2 membrane spanning proteins. Each of these proteins is roughly 30 kDa, and has of two Globular domains, Alpha-1, Alpha-2, Beta-1 and Beta-2. The two regions farthest away from the membrane are alpha-1 and beta-1. The two proteins link without Covalent Bonds. The MHC Class II protein mainly presents peptides, which have been digested from external sources. MHC Class II is normally only expressed by Antigen Presenting Cells (APC) which digest foreign protein. Within the RER the alpha and beta proteins of the molecule, associate with each other, while a third protein called the "invariant chain," is necessary for stabilizing the complex, without it, they will not associate. The MHC-invariant complex is then passed from the RER, into and out of, the Golgi body. It fuses with an Endocytic compartment, where an external protein has been sampled and degraded.

S100A11 is a member of the S100 family of proteins which contains two EF-hand calcium-binding motifs and is thought to be involved in the regulation of a number of cellular processes including cell cycle progression and differentiation. S100A11 may function in motility, invasion and tubulin polymerisation. S100 proteins are localized either in the cytoplasm or the nucleus of a wide range of cells. There are at least 13 members in the S100 gene family, which are located as a cluster on chromosome 1q21. Chromosomal rearrangements and altered expression of S100A11 have been implicated in tumor metastasis.

ADAM10 is part of the ADAM family which are cell surface proteins with a distinctive structure possessing both potential adhesion and protease domains. ADAM10 cleaves many proteins including TNF-alpha and E-cadherin. ADAM10 cleaves the membrane-bound precursor of tnf-alpha at 76- ala-|-val-77 to its mature soluble form. ADAM10 is in charge for the proteolytic release of several other cell-surface proteins, including ephrin-a2 and for constitutive and regulated alpha-secretase cleavage of amyloid precursor protein. ADAM10 is involved in the normal cleavage of the cellular prion protein. ADAM10 is involved in the cleavage of the adhesion molecule l1 at the cell surface and in the release of membrane vesicles, suggesting a vesicle-based protease activity. ADAM10 controls the proteolytic processing of notch and mediates lateral inhibition during neurogenesis.

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.

Mitochondrial rRNA methyltransferase 1 homolog (MRM1) is a part of the RNA methyltransferase TrmH family. MRM1 methylates the ribose of guanosine G-2270 in the peptidyl transferase center of the mitochondrial large ribosomal RNA (21S).