Search results

Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C, with molecular weight of 13260 Da, is composed of 120 amino acids, lacks carbohydrate and has two disulfide bridges located near the carboxyl terminus. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and, subsequently, the atherosclerosis and abdominal aortic aneurysm.

TNFRSF17 is a receptor for tnfsf13b/blys/baff and tnfsf13/april. TNFRSF17 promotes b-cell survival and plays a role in the regulation of humoral immunity. TNFRSF17 activates nf-kappa-b and jnk. TNFRSF17 is a member of the TNF-receptor superfamily. TNFRSF17 is expressed in mature B lymphocytes, and is invloved in B cell development and autoimmune response. TNFRSF17 specifically binds to the tumor TNFSF13B/TALL-1/BAFF, which causes NF-kappaB and MAPK8/JNK activation. TNFRSF17 binds to a variety of TRAF family members, and therefore transduces signals for cell survival and proliferation. TNFRSF17 is a type III membrane protein having 1 extracellular cysteine rich domain. Within the TNFRSF, it shares the highest homology with TACI. BCMA and TACI have both been shown to bind to APRIL and BAFF, members of the TNF ligand superfamily. BCMA expression has been found in immune organs. TNFRSF17 appears to be localized to the Golgi compartment. The binding of BCMA to APRIL or BAFF has been shown to stimulate IgM production in peripheral blood B cells and increase the survival of cultured B cells.

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.

Carcinoembryonic antigen (CEA) is a glycoprotein present in fetal digestive-tract tissues; it’s involved in cell adhesion. The production of CEA stops before birth. CEA is called tumor marker since its elevated levels are found in the serum from individuals with colorectal, gastric, pancreatic, lung and breast carcinomas and in heavy smokers.
There are also benign conditions that elevate CEA levels such as smoking, infection, inflammatory bowel disease, pancreatitis, cirrhosis of the liver, and some benign tumors (in the equivalent organs which have cancers with elevated CEA). Typically, higher levels of CEA are found in men, smokers, and older individuals.
The presence of CEA assists in screening, in evaluating recurrent or disseminated disease, and in determining the success of surgical removal of malignant tumors.
CEA levels can be used as indicators of treatment success. The normal values range from 0.0 to 2.5 ng/ml of serum (from blood), in non-smokers, a greater amount than that may be suggestive of cancer. Levels above 20 ng/ml before treatment are associated with cancer which has already metastasized. Benign conditions do not usually cause a CEA increase over 10 ng/ml.
The high levels of CEA should return to normal after successful therapy, however if during follow up there’s an elevation in CEA levels it indicates a recurrence of tumor.
Carcinoembryonic antigen family belongs to the immunoglobulin superfamily; it consists of 29 genes, 18 of which are normally expressed.

Stem cell factor / KIT ligand (SCF) is a cytokine which binds CD117 (c-Kit). SCF is also known as "steel factor" or "c-kit ligand". SCF exists in two forms, cell surface bound SCF and soluble (or free) SCF. Soluble SCF is produced by the cleavage of surface bound SCF by metalloproteases.
SCF is a growth factor important for the survival, proliferation, and differentiation of hematopoietic stem cells and other hematopoietic progenitor cells. One of its roles is to change the BFU-E (burst-forming unit-erythroid) cells, which are the earliest erythrocyte precursors in the erythrocytic series, into the CFU-E (colony-forming unit-erythroid).

SNCA or Alpha-synuclein is a protein with undisclosed function that mainly concentrated in the brain tissue, mainly in the tips of the neurons in the presynaptic terminals. Almost 1% of the proteins in the brain tissues are synucleins. The protein is located mainly in the hippocampus, thalamus, cerebellum & neocortex. Smaller amounts of the SNCA protein can be found in the neuroglial cells. The MITF protein regulates the SNCA expression in melanocytic cells.

Hepatitis A Virus Cellular Receptor 2 (HAVCR2) is a member of the immunoglobulin superfamily. HACVR2 controls macrophage activation. HACVR2 inhibits T-helper type 1 lymphocyte (Th1)-mediated auto- and alloimmune responses and stimulates immunological tolerance.

WNT1-inducible-signaling pathway protein 2 (WISP2) belongs to the WNT1 inducible signaling pathway (WISP) protein subfamily, which belongs to the connective tissue growth factor (CTGF) family. The CTGF family members are characterized by 4 conserved cysteine-rich domains: insulin-like growth factor-binding domain, von Willebrand factor type C module, thrombospondin domain and C-terminal cystine knot-like (CT) domain. WISP2 protein lacks the CT domain which is implicated in dimerization binding. WISP2 is possibly involved in bone remodeling. WISP2 is expressed in primary osteoblasts and fibroblasts. WISP2 stimulates osteoblast adhesion and inhibits osteocalcin production. WISP2 expression in colon tumors is reduced while the other 2 WISP members are overexpressed in colon tumors. WISP2 may play an imperative role in modulating bone turnover.

The secreted polypeptide noggin, encoded by the NOG gene, binds and inactivates members of the transforming growth factor-beta (TGF-beta) superfamily signaling proteins, such as bone morphogenetic protein-4 (BMP4). By diffusing through extracellular matrices more efficiently than members of the TGF-beta superfamily, noggin may have a principal role in creating morphogenic gradients. Noggin appears to have pleiotropic effect, both early in development as well as in later stages. It was originally isolated from Xenopus based on its ability to restore normal dorsal-ventral body axis in embryos that had been artificially ventralized by UV treatment. The results of the mouse knockout of noggin suggest that it is involved in numerous developmental processes, such as neural tube fusion and joint formation. Recently, several dominant human NOG mutations in unrelated families with proximal symphalangism (SYM1) and multiple synostoses syndrome (SYNS1) were identified; both SYM1 and SYNS1 have multiple joint fusion as their principal feature, and map to the same region (17q22) as NOG. All NOG mutations altered evolutionarily conserved amino acid residues. The amino acid sequence of human noggin is highly homologous to that of Xenopus, rat and mouse.

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.

Fibroblast Growth Factors (FGFs) comprise a family of at least eighteen structurally realted proteins that are involved in a multitude of physiological and pathological cellular processes, including cell growth, differentation, angiogenesis, wound healing and tumorgenesis. The biological activities of the FGFs are mediated by a family if type I transmembrane tyrosine kinases which undergo dimerization and autophosphorylation after ligand binding. Four distinct genes encoding closely related FGF receptors, FGFR-1to -4 are known. Multiple forms of FGFR-1 to -3 are generated by alternative splicing of the mRNAs. A frequent splicing event involving FGFR-1 and -2 results in receptors containing all three Ig domains, referred to as the alpha isoform, or only IgII and IgIII, referred to as the ? isoform. Only the alpha isoform has been identified for FGFR-3 and FGFR-4. Additional splicing events for FGFR-1 to -3, involving the C-terminal half of the IgIII domain encoded by two mutually exclusive alternative exons, generate FGF receptors with alternative IgIII domains (IIIb and IIIc). A IIIa isoform which is a secreted FGF binding protein containing only the N-terminal half of the IgIII domain plus some intron sequences has also been reported for FGFR-1. Mutations in FGFR-1 to -3 have been found in patients with birth defects involving craniosynostosis.

PIM2 is a serine/threonine protein kinase which is a part of the CAMK family. PIM2 is expressed in various tissues mainly in spleen, thymus, testis and small intestine. PIM2 is implicated in tumor phenotypes and participates in the formation and preservation of Long-Term Potentiation (LTP). PIM2 is also involved in the positive regulation of chondrocyte survival and autophagy in the epiphyseal growth plate.

Calmodulin-2 acts as an intracellular calcium sensor protein. When the intracellular Ca2+ concentration increases, calmodulin can bind up to four Ca2+, changing its conformation and regulating cellular functions such as activation or inhibition of a large number of enzymes, ion channels, and receptors. P53 protein stimulates CALM2 gene expression in 041 cells. CALM-2 is involved in the processes of Ca(2+)-induced neuronal cell death and the blockage of calmodulin attenuates brain injury after cerebral ischemia. Calmodulin-2 mediates the control of a large number of enzymes and other proteins by ca(2+). among the enzymes to be stimulated by the calmodulin-ca(2+) complex are a number of protein kinases and phosphatases.

CIB1 (Calcium and integrin binding 1) is regulatory protein with 50% homology to calmodulin and calcineurin B, that encodes a member of the calcium-binding protein family. CIB1 interacts with DNA-dependent protein kinase and may play a role in kinase-phosphatase regulation of DNA end joining. Also CIB1 is widely expressed and binds to a number of effectors, such as integrin ?IIb, PAK1, and polo-like kinases, in different tissues.

FLT3 ligand is a receptor for the fl cytokine has a tyrosine-protein kinase activity & a growth factor that regulates proliferation of early hematopoietic cells. Flt3-Ligand synergizes with other CSFs and interleukins to induce growth and differentiation.

Hexokinases phosphorylate glucose to produce glucose-6-phosphate, thus committing glucose to the glycolytic pathway. Hexokinase1 encodes a ubiquitous form of hexokinase which localizes to the outer membrane of mitochondria. Mutations in this gene have been associated with hemolytic anemia due to hexokinase deficiency. Alternative splicing of HXK1 results in five transcript variants which encode different isoforms, some of which are tissue-specific. Each isoform has a distinct N-terminus; the remainder of the protein is identical among all the isoforms. A sixth transcript variant has been described, but due to the presence of several stop codons, it is not thought to encode a protein.

BAK1 is a member of the BCL2 protein family. The BCL2 family members form oligomers or heterodimers and act as anti- or pro-apoptotic regulators which are involved in a wide variety of cellular activities. The BAK1 gene encodes a receptor-like kinase (RLK) with a putative extracellular domain, a single transmembrane domain, an intracellular-juxtamembrane domain, and a kinase domain. BAK1 localizes to mitochondria, and functions to induce apoptosis. BAK1 interacts with and accelerates the opening of the mitochondrial voltage-dependent anion channel, leading to a loss in membrane potential and the release of cytochrome c. Furthermore, BAK1 interacts with the tumor suppressor P53 after exposure to cell stress. BAK1 expression is linked to the progression of Prostate cancer.

C9orf103 is a member of the gluconokinase gntK/gntV family. C9orf103 takes part in carbohydrate acid metabolism and D-gluconate degradation.

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.

ATF1, a cyclic-AMP dependent transcription factor, is expressed in a large selection of cell types and can dimerize with CREB. MSK1 and MSK2 protein kinases are essential for the stress-induced phosphorylation of transcription factors CREB and ATF1 in primary embryonic fibroblasts. Epidermal growth factor induction of c-jun expression needs ATF1 and MEF2 sites in the c-jun promoter.

The epidermal growth factor receptor (EGF R) subfamily of receptor tyrosine kinases comprises four members: EGF R (also known as HER1, ErbB1 or ErbB), ErbB2 (Neu, HER-2), ErbB3 (HER-3), and ErbB4 (HER-4). All family members are type I transmembrane glycoprotein that has an extracellular domain which contains two cysteine-rich domains separated by a spacer region that is involved in ligand-binding, and a cytoplasmic domain which has a membrane-proximal tyrosine kinase domain and a C-terminal tail with multiple tyrosine autophosphorylation sites. The human EGF R gene encodes a 1210 amino acid (aa) residue precursor with a 24 aa putative signal peptide, a 621 aa extracellular domain, a 23 aa transmembrane domain, and a 542 aa cytoplasmic domain. EGF R has been shown to bind a subset of the EGF family ligands, including EGF, amphiregulin, TGF-a , betacellulin, epiregulin, heparin-binding EGF and neuregulin-2 in the absence of a co-receptor. Ligand binding induces EGF R homodimerization as well as heterdimerization with ErbB2, resulting in kinase activation, tyrosine phosphorylation and cell signaling. EGF R can also be recruited to form heterodimers with the ligand-activated ErbB3 or ErbB4. EGF R signaling has been shown to regulate multiple biological functions including cell proliferation, differentiation, motility and apoptosis. In addition, EGF R signaling has also been shown to play a role in carcinogenesis.

BCA-1 is a CXC chemokine that is highly expressed in thesecondary lymphoid organs, such as follicles of the spleen, lymph nodes, and Peyer's patches. CXCL13 promotes the migration of B lymphocytes (compared to T cells and macrophages), by stimulating calcium influx into, and chemotaxis of, cells expressing Burkitt's lymphoma receptor 1 (BLR1). BCA1 therefore function in the homing of B lymphocytes to follicles. Human BCA-1 shares a 64% amino acid sequence similarity with the mouse protein and 23 - 34% amino acid sequence identity with other known CXC chemokines. Recombinant or chemically synthesized BCA1 is a potent chemoattractant for B lymphocytes but not T lymphocytes, monocytes or neutrophils. BLR1, a G protein-coupled receptor originally isolated from Burkitt’s lymphoma cells, has now been shown to be the specific receptor for BCA1. Among cells of the hematopoietic lineages, the expression of BLR-1, now designated CXCR-5, is restricted to B lymphocytes and a subpopulation of T helper memory cells.