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Chemokine (C-X-C motif) ligand 2 (CXCL2) is a small cytokine belonging to the CXC chemokine family that is also called macrophage inflammatory protein 2-alpha (MIP2-alpha), Growth-regulated protein beta (Gro-beta) and Gro oncogene-2 (Gro-2). CXCL2 is 90% identical in amino acid sequence as a related chemokine, CXCL1. This chemokine is secreted by monocytes and macrophages and is chemotactic for polymorphonuclear leukocytes and hematopoietic stem cells. The gene for CXCL2 is located on human chromosome 4 in a cluster of other CXC chemokines. CXCL2 mobilizes cells by interacting with a cell surface chemokine receptor called CXCR2.

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 macrophage function. It is produced by certain tumor cell lines 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).

Cellular Repressor of E1A-Stimulated Genes 1 (CREG1) both activates and inhibits gene expression to stimulate cellular proliferation and hinder differentiation. CREG1 antagonizes transcriptional activation and cellular transformation by E1A. CREG1 shares partial sequence similarity with E1A and binds both the general transcription factor TBP and the tumor suppressor pRb in vitro. CREG1 contributes to the transcriptional control of cell growth and differentiation.

TIE-1 (tyrosine kinase with Ig and EGF homology domains 1) and TIE-2/Tek comprise a receptor tyrosine kinase (RTK) subfamily with unique structural characteristics: two immunoglobulin-like domains flanking three epidermal growth factor (EGF)-like domains and followed by three fibronectin type III-like repeats in the extracellular region and a split tyrosine kinase domain in the cytoplasmic region. These receptors are expressed primarily on endothelial and hematopoietic progenitor cells and play critical roles in angiogenesis, vasculogenesis and hematopoiesis. Human TIE-1 cDNA encodes a 1124 amino acid (aa) residue precursor protein with an 18 residue putative signal peptide, a 727 residue extracellular domain and a 354 residue cytoplasmic domain. Whereas two ligands have been described for TIE-2 [angiopoietin-1 (Ang1) and angiopoietin-2 (Ang2)], so far no ligand was found for TIE-1.

DHH is part of the Hedgehog family which encodes signaling molecules that are involved in regulating morphogenesis. DHH protein is a precursor that is autocatalytically cleaved, the N-terminal portion is soluble and contains the signalling activity while the C-terminal portion is involved in precursor processing. Additionally, the C-terminal product covalently attaches a cholesterol moiety to the N-terminal product, restricting the N-terminal product to the cell surface and preventing it from freely diffusing throughout the organism. Defects in DHH protein have been associated with partial gonadal dysgenesis (PGD) accompanied by minifascicular polyneuropathy. DHH plays a role both male gonadal differentiation and perineurial development.
DHH plays a role in intercellular signaling which is essential for a variety of patterning events during development. DHH functions as a spermatocyte survival factor in the testes & is essential for testes development.

TNFRSF14, a member of the TNF receptor superfamily, is a type I transmembrane protein. TNFRSF14 is expressed in peripheral blood T cells, B cells, monocytes and in various tissues enriched in lymphoid cells. TNFRSF14 operates as a co-stimulatory factor for the activation of lymphoid cells and as a deterrent to infection by herpesvirus. Additionally, TNFRSF14 encourages the proliferation of T cells, and triggers apoptosis of various tumor cells.

BTLA, also known as B & T Lymphocyte Associated, is an inhibitory molecule which is part of the Ig superfamily. BTLA is a type 1 transmembrane glycoprotein in the CD28 family of T cell costimulatory molecules. BTLA is a 3rd inhibitory receptor on T lymphocytes with resemblances to CTLA-4 & PD-1. Moreover, BTLA is a ligand for TNF (receptor) superfamily, TNFRSF14, and HVEM. BTLA-HVEM complexes negatively regulate T-cell immune responses.

PTX-2 or Pentraxin-2 is a phylogenetically conserved protein, commonly moving with homopentameric blood protein or with a protein that recognizes receptors of the innate immune system. The protein’s specific binding abilities may show that PTX-2 is specially bound in sites where injury accrued, therefore helps to eliminate damaged tissue by ways that are not phlogistics.

RELM-beta (Resistin-Like Molecule-beta) is a member of a recently identified family of secreted proteins containing a conserved cystein-rich C-terminus. The RELM family consists of resistin (also called FIZZ3), RELM-alfa (FIZZ1), RELM-beta (FIZZ2) and RELM-gamma. Only resisistin and RELM-beta were found in humans whereas all four RELM family members were identified in rodents.
RELM-beta appears to be produced as a homodimer exclusively by intestinal goblet cells and can be found in high quantities in stool. Remarkably, stool of germ-free mice displaying sterile intestinal tract does not contain RELM-beta until bacterial colonization takes place after pathogen-free mice entered natural environment. Some, but not all, colon carcinoma cell lines secrete RELM-beta into the cell culture supernatant.
The physiological function of RELM-beta is not known. High doses of recombinant RELM-beta showed hyperglycemic effects including lowered glucose disposal and increased hepatic glucose production in mice.

FIAF (fasting-induced adipose factor) a.k.a ANGPTL4 or PGAR or HFARP is an adipocytokine up-regulated by fasting, by peroxisome proliferator-activated receptor agonists, and by hypoxia. ANGPTL4 is found in human and mouse blood plasma both as a native protein and in a truncated form. In human white adipose tissue and SGBS adipocytes, only the native form of ANGPTL4 could be detected, whereas in mice the differentiation of mouse 3T3-L1 adipocytes is associated with the production of truncated ANGPTL4. However, the truncated ANGPTL4 is produced by human liver. In human blood plasma FIAF is mainly presented in a truncated form (FIAF-S2), whose levels treatment increases (as shown by experimental data). There is an inter individual variation in ANGPTL4 levels of both the truncated and the native form, however those levels were not influenced by prolonged semistarvation and are not associated with body mass index.

TNF Ligand Receptor Superfamily Member 25 (TNFRSF25) belongs to the TNF receptor superfamily that binds to the TNF-like protein TL1A. TNFRSF25 interacts directly with the adapter TRADD and regulates lymphocyte homeostasis. TNFRSF25 is also mediates activation of NF-kappa-B and induces apoptosis. TNFRSF25 signals are vital to exert T helper cell 2 effector activity in Th2-polarized CD4 cells and co-stimulate interleukin-13 production by glycosphingolipid-activated NKT cells.

TSLP protein is a hemopoietic cytokine which signals throughout a heterodimeric receptor complex composed of the thymic stromal lymphopoietin receptor & the Interleukin-7 receptor alpha chain. TSLP impacts myeloid cells thus induces the discharge of T cell-attracting chemokines from monocytes & increases the growth of CD11c(+) dendritic cells. TSLP is mainly expressed in the heart, liver and prostate. TSLP is related in its biological activities with IL-7 and binds with the heterodimeric receptor complex consisting of the Interleukin-7 receptor alpha chain & the TSLPR. Similar to IL-7, TSLP enhances phosphorylation of STAT3 and STAT5, though uses kinases excluding JAKs for its activation. TSLP induces the release of T cell-attracting chemokines such asTARC & MDC from monocytes & triggers CD11c(+) dendritic cells. TSLP activated dendritic cells primes naive T cells to manufacture pro-allergic cytokines such as Iinterleukin-4, Interleukin-5, Interleukin-13 and TNF-alpha whereas down-regulating Interleukin-10 and IFN-gamma play a role in the initiation of allergic inflammation.

ANXA5 is a member of the annexin family of calcium-dependent phospholipid binding proteins which are involved in membrane-related activity along exocytotic and endocytotic pathways. ANXA5 is a phospholipase A2 and protein kinase C inhibitory protein with calcium channel properties and takes part in cellular signal transduction, inflammation, growth and differentiation. ANXA5 is an anticoagulant protein that acts as an indirect inhibitor of the thromboplastin-specific complex, which is involved in the blood coagulation cascade. ANXA5 regulates coagulability in the blood stream by binding to phosphatidylserine and sulfatide. ANXA5 protects sinsuoidal endothelial cells from ischemia reperfusion damage. ANXA5 is necessary for normal CFTR chloride channel activity.

Chemokine (C-C motif) ligand 6 (CCL6) is a small cytokine belonging to the CC chemokine family that has only been identified in rodents.
In mice, CCL6 is expressed in cells from neutrophil and macrophage lineages, and can be greatly induced under conditions suitable for myeloid cell differentiation. It is highly expressed in bone marrow cultures that have been stimulated with the cytokine GM-CSF. Some low levels of gene expression also occur in certain cell lines of myeloid origin (e.g. the immature myeloid cell lines DA3 and 32D cl3, and the macrophage cell line P388D) that can also be greatly induced in culture with GM-CSF. However, in activated T cell lines, expression of CCL6 is greatly reduced. CCL6 can also be induced in the mouse lung by the cytokine interleukin 13. Mouse CCL6 is located on chromosome 11. The cell surface receptor for CCL6 is believed to be the chemokine receptor CCR1.

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.

Platelet endothelial cell adhesion molecule (PECAM1) induces susceptibility to atherosclerosis. PECAM1 averts phagocyte ingestion of closely apposed viable cells by transmitting detachment signals, and transforms function upon apoptosis, thus promoting tethering of dying cells to phagocytes. The encounter of a viable cell with a phagocyte via the homophilic interaction of PECAM1 on both cell surfaces as a result causing the viable cell's active repulsion from the phagocyte.

The type II transmembrane protein FASLG is a member of the tumor necrosis factor (TNF) superfamily. A fas ligand/receptor interaction has a significant part in the regulation of the immune system and the advancement of cancer. FASLG is expressed on the activated T cell surface as a nondisulfidelinked homotrimer. FASLG binding to Fas/CD95/TNFRSF6 on a nearby cell prompts apoptosis in the Fas expressing cell. FASLG is released from the cell surface by metalloproteinases as a soluble molecule that stays trimeric and is able to bind with Fas, but its capability to activate apoptosis is radically reduced. In addition, FASLG binds to DcR3 - a soluble trap receptor with no signal transduction capabilities. Flawed Fas-mediated apoptosis causes oncogenesis in addition to drug resistance in existing tumors. Constitutive expression of FASLG in a variety of tumors enables their immune evasion. Both mouse and human FASLG are active on mouse and human cells.

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.

The hematopoietic growth factor GM-CSF or granulocyte macrophage colony-stimulating factor, stimulates the development of neutrophils & macrophages, enhance proliferation and development of early erythroid megakaryocytic & eosinophilic progenitor cells. GM-CSF is secreted from the fibroblasts, monocytes, T-lymphocytes & endothelial cells. This protein blocks the migration of neutrophils & induces the biological activity of mature end-cells.

Myoglobin is a member of the globin superfamily and exists in skeletal and cardiac muscles. Myoglobin is a haemoprotein that contributs to intracellular oxygen storage and transcellular facilitated diffusion of oxygen. Myoglobin is frequently referred to as having an "instant binding tenacity" to oxygen given its hyperbolic oxygen dissociation curve. Different organisms are able to hold their breaths longer due to high concentrations of myoglobin in their muscle cells. Myoglobin is responsible for the pigments that make meat red. The color of the meat is partly determined by the charge of the iron atom in myoglobin and the oxygen attached to it. Myoglobin is found in Type I muscle, Type II A and Type II B, but it is mostly deemed that myoglobin is not found in smooth muscle.

MHC 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.

The FGFs are a family of more than 20 small (~17–26 kDa) secreted peptides. The initial characterization of these proteins focused on their ability to stimulate fibroblast proliferation. This mitogenic activity was mediated through FGF receptors (FGFRs) 1, 2, or 3. A fourth closely related tyrosine kinase receptor (FGFR4) was able to bind the FGFs but did not lead to a mitogenic response.
FGFs modulate cellular activity via at least 5 distinct subfamilies of high-affinity FGF receptors (FGFRs): FGFR-1, -2, -3, and -4, all with intrinsic tyrosine kinase activity and, except for FGFR-4, multiple splice isoforms, and FGFR-5, which lacks an intracellular kinase domain. There is growing evidence that FGFRs can be important for regulation of glucose and lipid homeostasis. The overexpression of a dominant negative form of FGFR-1 in ? cells leads to diabetes in mice, which thus implies that proper FGF signaling is required for normal ? cell function and glycemia maintenance. FGFR-2 appears to be a key molecule during pancreatic development. Moreover, FGFR-4 has been implicated in cholesterol metabolism and bile acid synthesis.
FGF-19, has been shown to cause resistance to diet-induced obesity and insulin desensitization and to improve insulin, glucose, and lipid profiles in diabetic rodents. Since these effects, at least in part, are mediated through the observed changes in metabolic rates, FGF-19 can be considered as a regulator of energy expenditure.
FGF-21 is preferentially expressed in liver, but an exact knowledge of FGF-21 bioactivity and its mode of action have been lacking to date. FGF-21 is a potent activator of glucose uptake on adipocytes, protects animals from diet-induced obesity when overexpressed in transgenic mice, and lowers blood glucose and triglyceride levels when therapeutically administered to diabetic rodents.

SARS Coronavirus is an enveloped virus containing three outer structural proteins, namely the membrane (M), envelope (E), and spike (S) proteins. Spike (S)-glycoprotein of the virus interacts with a cellular receptor and mediates membrane fusion to allow viral entry into susceptible target cells. Accordingly, S-protein plays an important role in virus infection cycle and is the primary target of neutralizing antibodies.
It has recently been shown that SARS (severe acute respiratory syndrome) is caused by a human coronavirus. Human coronaviruses are the major cause of upper respiratory tract illness, such as the common cold, in humans. Coronaviruses are positive-stranded RNA viruses, featuring the largest viral RNA genomes known to date (27-31 kb). The first step in coronavirus infection is binding of the viral spike protein, a 139-kDa protein, to certain receptors on host cells. The spike protein is the main surface antigen of the coronavirus. The glycosilated spike protein (as well as the nucleocapsid protein) can be detected in infected cell culture supernatants with antisera from SARS patients.