Search results

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).

Hepatitis B is one of a few known non-retroviralviruses which employ reverse transcriptionas a part of its replication process. (HIV, a completely unrelated virus, also uses reverse transcription, but it is a retrovirus.) HBV invades the cell by binding to surface receptor and become internalized. The viral core particles then migrate to the hepatocyte nucleus and the partially double-stranded, relaxed circular genomes (RC-DNA) are repaired to form a covalently closed circular DNA (cccDNA), which is the template for viral genomic and sub-genomic RNAs by cellular RNA polymerase II. Of these, the pregenomic RNA (pgRNA is selectively packaged into progeny capsids and is then reverse-transcribed into new RC-DNA. The core can either bud into the endoplasmic reticulum to be enveloped or exported from the cell or recycled back into the genome for conversion to cccDNA.

Chemokine (C-C motif) ligand 7 (CCL7) is a small cytokine known as a chemokine that was previously called monocyte-specific chemokine 3 (MCP3). Due to CCL7 possessing two adjacent N-terminal cysteine residues in its mature protein, it is classified among the subfamily of chemokines known as CC chemokines. CCL7 specifically attracts monocytes, and regulates macrophagefunction. It is produced by certain tumor celllines and by macrophages. This chemokine is located on chromosome 17 in humans, in a large cluster containing many other CC chemokines and is most closely related to CCL2(previously called MCP1) .

CD34 is a single chain transmembrane glycoprotein which is selectively expressed on human lymphoid and myeloid hemapoietic progenitor cells. CD34 has been used to measure angiogenesis, which reportedly predicts tumor recurrence.

Acireductone dioxygenase 1 (ADI1) is a part of the acireductone dioxygenase family of metal-binding enzymes, which are involved in methionine salvage. ADI1 regulates mRNA processing in the nucleus, and carries out different functions depending on its localization. Related pseudogenes have been defined on chromosomes 8 and 20. ADI1 down-regulates cell migration arbitrated by MMP14.

Poly (ADP-Ribose) Polymerase 2 (PARP2) contains a catalytic domain which is homologous to that of poly (ADP-ribosyl) transferase but lacks an N-terminal DNA binding domain which activates the C-terminal catalytic domain of poly (ADP-ribosyl) transferase. PARP2 is capable of catalyzing a poly (ADP-ribosyl)ation reaction. The basic residues within the N-terminal area of this protein can bear potential DNA-binding properties, and can be engaged in the nuclear and/or nucleolar targeting of the protein. There has been found two alternatively spliced transcript variants encoding distinct isoforms.

TNFR1 belongs to the TNF-receptor superfamily. TNFR1 is a receptor for TNFSF2/TNF-alpha and homotrimeric TNFSF1/lymphotoxin-alpha.
There are 2 types of soluble TNF receptors: sTNFR-I and sTNFR-II, which act to neutralize the biological activities of TNF alpha and TNF beta. The levels of these soluble receptors seem to increase as a result of shedding of the extracellular domains of the membrane bound receptors. TNF-a, TNFR1 and TNFR2 have roles in cellular differentiation. TNFR1 and TNFR2 function in cell type-specific renal injury.
TNFR1 is capable of signaling both cell survival and apoptosis. TNFR1-induced apoptosis requires 2 sequential signaling complexes. TNFR1 is capable of activating NF-kappaB, mediate apoptosis, and function as a regulator of inflammation. Oxidative stress promotes TNFR1 and TNFR2 self-interaction, ligand-independent and enhanced ligand-dependent TNF signaling. TNFR1 contributes to the induction of non-cytocidal TNF effects including anti-viral state and activation of the acid sphingomyelinase. Human TNFR1 has a major region which controls cell surface expression. High levels of soluble TNF receptors are found in the amniotic fluid of pregnant women.
Germline mutations of the extracellular domains of TNFR1 are linked to the autosomal dominant periodic fever syndrome. The impaired receptor clearance is believed to be a mechanism of the disease. Familial hibernian fever (FHF) is caused by defects in TNFRSF1A gene.

Heparanase is an endo ß-D-glucuronidase, which degrades heparan sulfate side chains of heparan sulfate proteoglycans (HSPGs) in the extracellular matrix. Heparanase plays an important role in ECM degradation, facilitating the migration and extravasation of tumor cells and inflammatory leukocytes (1,2,3). Upon degradation, heparanase releases growth factors and cytokines that stimulate cell proliferation and chemotaxis (4,5). Heparanase is a heterodimer comprised of a 50 kDa subunit harboring the active site and a 8 kDa subunit. It is produced as a latent 65 kDa precursor and proteolytically processed to its active form (1,6). Heparanase is highly expressed in myeloid leukocytes (i.e. neutrophils) in platelets and in human placenta. Human heparanase was found to be upregulated in various types of primary tumors, correlating in some cases with increased tumor invasiveness and vascularity and with poor prospective survival (7,8).

PDGF-BB is a member of the platelet-derived growth factor family. The four members of this family are mitogenic factors for cells of mesenchymal origin and are characterized by a motif of eight cysteines. This gene product can exist either as a homodimer (PDGF-BB) or as a heterodimer with the platelet-derived growth factor alpha polypeptide (PDGF-AB), where the dimers are connected by disulfide bonds. Mutations in this gene are associated with meningioma. Reciprocal translocations between chromosomes 22 and 7, at sites where this gene and that for COL1A1 are located, are associated with a particular type of skin tumor called dermatofibrosarcoma protuberans resulting from unregulated expression of growth factor. Two splice variants have been identified for this gene.

Defensins form a family of microbicidal and cytotoxic peptides made by neutrophils. Members of the defensin family are highly similar in protein sequence. This gene encodes defensin, beta 103A, which has broad spectrum antimicrobial activity and may play an important role in innate epithelial defense.

The somatomedins, or insulin-like growth factors (IGFs), comprise a family of peptides that takes part in mammalian growth and development. IGF1 mediates various growth-promoting effects of growth hormone (GH; MIM 139250). Early studies showed that growth hormone did not directly stimulate the incorporation of sulfate into cartilage, but rather acted through a serum factor, termed 'sulfation factor,' which later became known as 'somatomedin' (Daughaday et al., 1972). 3 main somatomedins have been characterized: somatomedin C (IGF1), somatomedin A (IGF2; MIM 147470), and somatomedin B (MIM 193190) (Rotwein, 1986; Rosenfeld, 2003).

Darbepoetin is a mutant recombinant human EPO-Alpha protein re-engineered, containing 5 amino acid changes at N30, T32, V87, N88, T90. Darbepoetin exhibits longer half-life stimulating red blood cell production than Erythropoietin. Darbepoetin maintains hemoglobin more effectively compared to EPO-Alpha.

IFN-gamma produced by lymphocytes activated by specific antigens or mitogens.
IFN-gamma, in addition to having antiviral activity, has important immunoregulatory functions, it is a potent activator of macrophages, and has antiproliferative effects on transformed cells and it can potentiate the antiviral and antitumor effects of the type I interferons.

PDX1 activates insulin, somatostatin, glucokinase, islet amyloid polypeptide and glucose transporter type 2 gene transcription. IPF1 is particularly involved in glucose-dependent regulation of insulin gene transcription. Pancreas Duodenum Homeobox-1 binds preferentially the DNA motif 5'-[ct]taat[tg]-3'. During development, specifies the early pancreatic epithelium, permitting its proliferation, branching and subsequent differentiation. At adult stage, it is required for maintaining the hormone-producing phenotype of the beta-cell.

Phl p 12.0101 a profilin, is a minor grass pollen allergen which is involved in cytoskeleton mobility by interacting with actin filaments. It is well recognized that IgE binding can cause immune cross-reactivity with profilins of plant-derived foods and pollen profilin.

A fusion tag called FLAG consists of eight amino acids (AspTyrLysAspAspAspAspLys) including an enterokinase-cleavage site. FLAG is specifically designed for immunoaffinity chromatography. It allows elution under non-denaturing conditions. Several antibodies against this peptide have been developed. One antibody denoted as M1 binds the peptide in the presence of bivalent metal cations preferably Ca(+). Elution is effected by chelating agents. Another strategy is competitive elution with excess of free Flag Peptide. The FLAG peptide purifies and detects recombinant fusion proteins. FLAG peptide is useful in Western blotting, immunocytochemistry, immunoprecipitation, flow cytometry, protein purification, and in the study of protein-protein interactions, cell ultrastructure, and protein localization. Flag peptide is a hydrophilic tag which significantly improves the detection and purification of recombinant fusion proteins.

Ornithine aminotransferase is a key enzyme in the pathway that converts arginine and ornithine into the major excitatory and inhibitory neurotransmitters glutamate and GABA. Ornithine aminotransferase (OAT) is a 49kDa nucleus-encoded protein imported into mitochondria to give the mature 48kDa OAT polypeptide. It is found in humans, animals, insects, plants and microorganisms. The OAT has a sex-differential expression in the mouse kidney. OAT plays central physiological roles in amino acid metabolism. OAT shows a large structural and mechanistic similarity to other enzymes from the subgroup III of aminotransferases that transfer an amino group from a carbon atom which doesn’t carry a carboxyl function. OAT is vital for nitrogen recycling from arginine but not for the stress-induced proline accumulation. OAT enzyme deficiency causes the autosomal recessive eye disease Gyrate Atrophy.

SULT2A1 is a member fo the sulfotransferase family. SULT2A1 is primarily expressed in liver and adrenal tissues, and to a lesser extent in kidney. SULT2A1 catalyzes the 3'-phosphoadenosine 5'-phosphosulfate-dependent sulfation of an extensive selection of steroids in human liver and adrenal tissues, and in addition is responsible for a larg number of the sulfation of bile acids in human liver.

GSK3B is a serine-threonine kinase that belongs to the glycogen synthase kinase subfamily. GSK3B is involved in energy metabolism, neuronal cell development, and body pattern formation. Polymorphisms in the GSK3B gene have been implicated in modifying risk of Parkinson disease, and studies in mice show that overexpression of the GSK3B gene may be significant to the pathogenesis of Alzheimer disease.

ACY1 is a cytosolic, homodimeric, zinc-binding enzyme that catalyzes the hydrolysis of acylated L-amino acids to L-amino acids and acyl group, and has been postulated to take part in the catabolism and salvage of acylated amino acids. Defects in ACY1 are the source of aminoacylase-1 deficiency (ACY1D). ACY1D results in a metabolic disorder manifesting with encephalopathy, unspecific psychomotor delay, psychomotor delay with atrophy of the vermis and syringomyelia, marked muscular hypotonia or normal clinical features. Epileptic seizures are a frequent feature.

Trichomonas vaginalis, an anaerobic, flagellated protozoan parasite, is most dominant protozoan causing sexual transmitted disease. T. vaginalis induced vaginal tract infection occurs as multiple steps involving interactions between host macromolecules and protozoan virulent factor. Adhension protein P65 of T. vaginalis has a vital part in assisting the penetration into vaginal tract surface.

ADP-ribosylation factor 3 (ARF3) belongs to the human ARF gene family. This family encodes small guanine nucleotide-binding proteins which stimulate the ADP-ribosyltransferase activity of cholera toxin and have a role in vesicular trafficking and as activators of phospholipase D. ARF3 functions as an allosteric activator of the cholera toxin catalytic subunit, an ADP-ribosyltransferase. ARF3 is involved in protein trafficking; may modulate vesicle budding and uncoating within the Golgi apparatus. The ARF3 gene is comprised of 5 exons and 4 introns.

Active IL-12 is a p70 disulphide-linked dimer composed of p35 and p40 subunits. The protein is a pleiotropic cytokine produced primarily by antigen presenting cells and has multiple effects on T lymphocytes and natural killer cells in terms of stimulating cytotoxicity, proliferation, production of other cytokines and Th1 subset differentiation.

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.