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The Trefoil Factor peptides (TFF1, TFF2 and TFF3) are stable secretory proteins expressed in the gastrointestinal tract (gastric mucosa), and are involved in intestinal mucosal defense and repair. TFF1 is an essential protein for normal differentiation of the antral and pyloric gastric mucosa and functions as a gastric-specific tumor suppressor gene. TFF1 is a stabilizer of the mucous gel overlying the gastrointestinal mucosa that provides a physical barrier against various noxious agents. TFF1 protects the mucosa from isults, stabilizes the mucus layer, & affects healing of the epithelium. TFF1 is commonly expressed in tumors. TFF1 is related with the cell membrane of MCF-7 cells. High levels of TFF1 and TFF2 are found in serum from inflammatory bowel disease.

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.

Zinc Finger HIT-Type Containing 3 (ZNHIT3) which contains one HIT-type zinc finger, requires the presence of thyroid hormone for its interaction. Thyroid receptor interacting proteins particularly interact with the ligand binding domain of the thyroid receptor (TR).

NPPC is proteolytically managed to create a secreted hormone of the natriuretic peptide family. NPPC is vasoactive and natriuretic and controls the evolution and differentiation of cartilaginous growth plate chondrocytes.

IL-12 is a heterodimeric cytokine that stimulates the production of IFNgamma from T-cells and natural killer cells, and also induces differentiation of Th1 helper cells. IL-12 is an initiator of cell-mediated immunity.

TGFB2 is a 27.08 kDa protein having two identical 118 amino acid peptide chains linked by a single disulfide bond. TGFB2 is part of a family of five related cytokines that have an extensive variation of normal and neoplastic cells, indicating the importance of these homo-dimmer proteins as multi-functional regulators of cellular activity. The three mammalian isoforms of TGF-β (TGFb1, TGFb2 and TGFb3) signal through the same receptor and stimulate similar biological responses. They are involved in physiological processes as embryogenesis, tissue remodelling and wound healing.

Sorcin (SRI) which is a 22kDa calcium-binding protein was originally identified in multidrug-resistant cells. Sorcin, which modulates excitation-contraction coupling in the heart, contributes to calcium homeostasis in the heart sarcoplasmic reticulum.

RANKL binds to tnfrsf11b/opg and to tnfrsf11a/rank. Osteoclast differentiation and activation factor. Augments the ability of dendritic cells to stimulate naive t-cell proliferation. May be an important regulator of interactions between t-cells and dendritic cells and may play a role in the regulation of the t-cell-dependent immune response. sRANKL may also play an important role in enhanced bone-resorption in humoral hypercalcemia of malignancy. By injecting soluble RANKL, novel osteopenia model mice were established in only 50 hours. Degree of bone loss can be controlled by changing doses of sRANKL. RANKL can be used in establishing osteopenia model for in vivo screening of drugs for osteoporosis, determination of effect and mechanism, evaluation of bone anabolic drugs.

GH-releasing peptides (GHRPs) are synthetic peptides that like GHRH act directly on pituitary somatotrophs to stimulate GH release. Growth hormone (GH) release is stimulated by a variety of synthetic secretagogues, of which growth hormone-releasing hexapeptide (GHRP-6) has been most thoroughly studied; it is thought to have actions at both pituitary and hypothalamic site.

TPM4 is a member of the tropomyosin family. Tropomyosins exist in practically all eukaryotic cells (both muscle and nonmuscle), where they bind actin filaments and function to modulate actin-myosin interaction and stabilize actin filament structure. TPM4 binds to actin filaments in muscle and nonmuscle cells and plays a central role, in connection with the troponin complex, in the calcium dependent regulation of vertebrate striated muscle contraction.

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.

COMT catalyzes the transfer of a methyl group from S-adenosylmethionine (SAM) to catechol substrates such as the neurotransmitters. This O-methylation results in one of the main degradative pathways of the catecholamine transmitters. COMT COMT is located in the postsynaptic neuron and is involved in the metabolism of catechol estrogen drugs used in the treatment of hypertension, asthma, Parkinson disease and the inactivation of catecholamine neurotransmitters though enzymatic degradation. COMT appears in tissues in 2 forms, a soluble form and a membrane-bound form which differ in their N-termini. COMT inhibitors increase its availability and are used in the treatment of patients with Parkinson's disease.

Profilin-1 also known as Pfn1 is a ubiquitous actin monomer-binding protein which is a member of the profilin family. Pfn1 significantly enhances skin wound healing in-vitro as well as in-vivo which is mediated by purinergic receptors. Furthermore, Pfn1 is also active in endothelial cell migration and vessel sprouting. Pfn1 is considered to regulate actin polymerization in response to extracellular signals.

NF-kappa-B inhibitor beta (NFKBIB) is a member of the NF-kappa-B inhibitor family, which inhibit NF-kappa-B by complexing with, and trapping it in the cytoplasm. Phosphorylation of serine residues on these proteins by kinases marks them for destruction via the ubiquitination pathway, thus allowing activation of the NF-kappa-B, which translocates to the nucleus to act as a transcription factor.

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.

NUTF2 assists in protein transport into the nucleus and interacts with the nucleoporin p62 and with Ran. NUTF2 plays a role at a relatively late stage of nuclear protein import, subsequent to the initial docking of nuclear import ligand at the nuclear envelope. NUTF2 is part of a multicomponent system of cytosolic factors that come together at the pore complex during nuclear import.

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).

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.

a-Synuclein (amino acids 1-140), an acidic neuronal protein of 140 amino acids, is extremely heat-resistant and is natively unfolded with an extended structure primarily composed of random coils. a-synuclein has been suggested to be implicated in the pathogenesis of Parkinson’s disease and related neurodegenerative disorders, and more recently, to be an important regulatory component of vesicular transport in neuronal cells. Moreover, recent studies have shown that a-synuclein has chaperone activity and that this activity is lost upon removing its C-terminal acidic tail (amino acids 96-140).

Nephroblastoma Overexpressed (NOV) is a member of the CCN family of secreted cysteine rich regulatory proteins. The full length NOV protein is comprised of 4 structural domains, which present distinct, and sometimes opposing, biological activities. An elevated expression of NOV is linked with certain tumors, including Wilm’s tumor and most nephroblastomas. On the other hand, in other tumor types and certain cancer cell lines, increased tumorgenicity and proliferation is associated with decreased NOV expression.

Fibroblast growth factor 16 (FGF16) is a member of the large FGF family, whose members are heparin-binding growth factors with a core 120 amino acid (a.a.) FGF domain which allows for a common tertiary structure. Human FGF16 cDNA is a 207 aa precursor protein with one N-linked glycosylation site. FGF16 though lacking a typical signal peptide, is efficiently produced by mechanisms other than the classical protein secretion pathway. FGF16 is expressed in cardiac cells and is required for proper heart development. FGF16 gene mutation was also observed in individuals with metacarpal 4-5 fusion. FGF16 has an imperative role in the regulation of embryonic development, cell proliferation and cell differentiation, and is required for normal cardiomyocyte proliferation and heart development.

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), and VEGFR-3 (Flt-4). Their expression is almost exclusively restricted to endothelial cells, but VEGFR-1 can also be found on monocytes. All VEGF-receptors have seven immunoglobulin-like extracellular domains, a single transmembrane region and an intracellular split tyrosine kinase domain. VEGFR-2 has a lower affinity for VEGF than the Flt-1 receptor, but a higher signalling activity. Mitogenic activity in endothelial cells is mainly mediated by VEGFR-2 leading to their proliferation. Differential splicing of the flt-1 gene leads to the formation of a secreted, soluble variant of VEGFR-1 (sVEGFR-1). No naturally occurring, secreted forms of VEGFR-2 have so far been reported. The binding of VEGF165 to VEGFR-2 is dependent on heparin.

Myostatin (GDF-8) is expressed uniquely in human skeletal muscle as a 12 kDa mature glycoprotein consisting of 113 amino acid residues and secreted into plasma. Myostatin is a member of the transforming growth factor ? superfamily of secreted growth and differentiation factors that is essential for proper regulation of skeletal muscle mass. Studies have shown that myostatin could play an important role in cardiac development and physiology.

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. CSF-1 induces cells of the monocyte/macrophage lineage. It plays a role in immunological defenses, bone metabolism, lipoproteins clearance, fertility and pregnancy.