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MX2 is a member of 2 protein families: the dynamin family and the large GTPases family. MX2 has a cytoplasmic and nuclear structure which is found in a granular pattern in the heterochromatin region under the nuclear envelope. The nuclear form has a NLS (nuclear localization signal) at the amino terminal end however it is missing in the cytoplasmic form as a result of the use of a different translation start codon. MX2 is upregulated by IFN-a, but unlike myxovirus resistance protein 1 has no antiviral activity.

HGF, also known as scatter factor (SF) and Hepatocyte growth factor, is secreted from mesenchymal cells, targets and acts mainly on epithelial and endothelial cells. The protein is a paracrine cellular growth, motility and morphogenic factor. HGF can also be part of haemopoietic progenitor cells and T cells. HGF has a crucial role in embryonic organ development, mainly in myogenesis. In adults HGF takes part in organ regeneration and wound healing.

Apolipoprotein H (APOH) attaches to numerous kinds of negatively charged substances for instance heparin, phospholipids, and dextran sulfate. APOH prevents activation of the intrinsic blood coagulation cascade by attaching to phospholipids on the surface of damaged cells. APOH expressed by the liver and secreted in the plasma.

Matrix metalloproteinases are a family of zinc and calcium-dependent endopeptidases that break down extracellular matrix proteins. The MMP9 is secreted as a 92kDa zymogen. Cleavage of ProMMP-9 results in the active enzyme, having a molecular weight of approximately 82kDa. MMP9 is composed of the following domains: a gelatin-binding domain consisting of three fibronectin type II units, a catalytic domain containing the zinc-binding site, a proline-rich type V collagen-homologous domain and a hemopexin-like domain. MMP9 is produced by the several cell types: monocytes, macrophages, neutrophils, keratinocytes, fibroblasts, osteoclasts and endothelial cells. MMP9 is involved in inflammatory responses, tissue remodeling, wound healing, tumor growth and metastasis. MMP9 may also play an important part in local proteolysis of the extracellular matrix and in leukocyte migration, as well as in bone osteoclastic resorption. MMP9 cleaves type IV and type V collagens into large C-terminal three quarter fragments and shorter N-terminal one quarter fragments. MMP9 can also degrade fibronectin but not laminin or Pz-peptide.
MMP9 defects may be a cause of susceptibility to intervertebral disc disease (IDD), also known as lumbar disk herniation (LDH).

E-cadherin (uvomorulin, cell-CAM120/80) is a calcium dependent cell adhesion molecule expressed predominately in epithelial tissues. It plays an important role in the growth and development of cells via the mechanisms of control of tissue architecture and the maintenance of tissue integrity. Numerous studies have demonstrated that reduction and/or loss of Ecadherin expression in carcinomas correlates positively with the potential of these tumors for invasion and metastasis.

TIMP2 belongs to the TIMP gene family. The proteins encoded by this gene family are natural inhibitors of the matrix metalloproteinases, a group of peptidases that take part in degradation of the extracellular matrix. Besides having an inhibitory role against metalloproteinases, the encoded protein has a exclusive part among TIMPfamily members in its capability to directly suppress the proliferation of endothelial cells. Consequently, the encoded protein is crucial to the conservation of tissue homeostasis by suppressing the production of quiescent tissues as an answer to angiogenic factors, and by inhibiting protease activity in tissues undergoing renovation of the extracellular matrix.

Recombinant Human Lipocalin-2 also called Neutrophil Gelatinase Associated Lipocalin (NGAL) belongs to a family of lipocans which include 25 proteins (including a1-microglobulin and b-lactoglobulin), which are characterized by their ability to bind small lipophilic substances in their hydrophobic core.
They thereby serve as transporters of substances like retinal, biliverdins & prostaglandins. There are indications that NGAL is involved in modulation of the inflammatory response and is found in the plasma of patients after stroke.

Mediator of ErbB2-driven cell motility 1 (MEMO1) is a member of the UPF0103 family. MEMO1 regulates cell migration by transmitting extracellular chemotactic signals to the microtubule cytoskeleton. Furthermore, MEMO1 controls the localization of APC and CLASP2 to the cell membrane, using the regulation of GSK3B activity. MEMO1 is essential for breast carcinoma cell migration, suggesting a key role in tumorigenesis. MEMO1 is also a mediator of ERBB2 signaling.

E1 and E2 glycoproteins form a heterodimer which is involved in virus attachment to the host cell, virion internalization via clathrin-dependent endocytosis and fusion with host membrane. E1/E2 heterodimer binds to human LDLR, CD81 and SCARB1/SR-BI receptors, however this binding insufficient for infection, some additional liver specific cofactors may be required. The fusion function may perhaps be conducted by E1. E2 hinders human EIF2AK2/PKR activation, preventing the establishment of an antiviral state. E2 is a viral ligand for CD209/DC-SIGN and CLEC4M/DC-SIGNR, which are respectively located on dendritic cells (DCs), and on liver sinusoidal endothelial cells and macrophage-like cells of lymph node sinuses. These interactions allow seizure of circulating HCV particles by these cells and subsequent diffusion to permissive cells.

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.

TNF-related apoptosis-inducing ligand (TRAIL) is a ligand molecule which induces apoptosis. It is a type II transmembrane protein with homology to other members of the tumor necrosis factor family.
In humans, the gene that encodes for TRAIL is located at chromosome 3q26. TRAIL binds to the death receptors, DR4 and DR5. The process of apoptosis is caspase-8-dependent. This protein preferentially induces apoptosis in transformed and tumor cells, but does not appear to kill normal cells although it is expressed at a significant level in most normal tissues.

Protein Phosphatase 2C alpha is a member of the PP2C family of Ser/Thr protein phosphatases. PP2C family members are known to be negative regulators of cell stress response pathways. This phosphatase dephosphorylates, and negatively regulates the activities of, MAP kinases and MAP kinase kinases. It has been shown to inhibit the activation of p38 and JNK kinase cascades induced by environmental stresses. This phosphatase can also dephosphorylate cyclin-dependent kinases, and thus may be involved in cell cycle control. Overexpression of this phosphatase is reported to activate the expression of the tumor suppressor gene TP53/p53, which leads to G2/M cell cycle arrest and apoptosis. Three alternatively spliced transcript variants encoding two distinct isoforms have been described. Protein phosphatase 2C(PP2Cα) is a Mn2+- or Mg2+-dependent protein serine/threonine phosphatase that is essential for regulating cellular stress response in eukaryotes.

EBNA1BP2 is a part of the EBP2 family which is required for the processing of the 27S pre-rRNA. EBNA1BP2 interacts with EBV EBNA1. EBNA1-EBP2 interaction is essential for the stable segregation of EBV episomes throughout cell division.

HCV is a small 50nm, enveloped, single-stranded, positive sense RNAvirus in the family Flaviviridae.
HCV has a high rate of replication with approximately one trillion particles produced each day in an infected individual. Due to lack of proofreading by the HCV RNA polymerase, the HCV has an exceptionally high mutation rate, a factor that may help it elude the host's immune response. Hepatitis C virus is classified into six genotypes(1-6) with several subtypes within each genotype. The preponderance and distribution of HCV genotypes varies globally. Genotype is clinically important in determining potential response to interferon-based therapy and the required duration of such therapy. Genotypes 1 and 4 are less responsive to interferon-based treatment than are the other genotypes (2, 3, 5 and 6).

Activins are homodimers or heterodimers of the different β subunit isoforms, part of the TGFβ family. Mature Activin A has two 116 amino acids residues βA subunits (βA-βA). Activin displays an extensive variety of biological activities, including mesoderm induction, neural cell differentiation, bone remodelling, haematopoiesis, and reproductive physiology. Activins takes part in the production and regulation of hormones such as FSH, LH, GnRH and ACTH. Cells that are identified to express Activin A include fibroblasts, endothelial cells, hepatocytes, vascular smooth muscle cells, macrophages, keratinocytes, osteoclasts, bone marrow monocytes, prostatic epithelium, neurons, chondrocytes, osteoblasts, Leydig cells, Sertoli cells, and ovarian granulosa cells.

Membrane cofactor protein isoform 14 (CD46), is a type I membrane protein which has cofactor activity for inactivation of complement components C3b and C4b by serum factor I. This function resides in the complement control protein repeats (CCPs), with CCP1–4 vital for regulation. CD46 is also involved in the fusion of the spermatozoa with the oocyte during fertilization. CD46 is common in thymocytes, T cells, B cells, monocytes, granulocytes, NK cells, platelets, endothelial cells, epithelial cells, fibroblasts, placenta and sperm.

EIF4E is part of the eukaryotic initiation factor 4 families, controls translation of maternal mRNAs in early embryos before the onset of zygotic transcription. EIF4E identifies and binds to the 7 methyl GTP cap structure of eukaryotic mRNAs, thus modulates the initiation of translation. EIF4E enables ribosome binding by inducing the unwinding of the mRNAs secondary structures.

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.

SULT1E1 catalyzes the sulfate conjugation of many hormones, neurotransmitters, drugs, and xenobiotic compounds. These cytosolic enzymes are different in their tissue distributions and substrate specificities. Decreased SULT1E1 expression is linked with estrogen-dependent endometrial carcinomas. Altered cellular proliferation was detected in cells stably expressing SULT1E1.

PPP1CA is one of the 3 catalytic subunits of protein phosphatase 1 (PP1). PP1 is a serine/threonine specific protein phosphatase which is involved in the regulation of a variety of cellular processes, such as cell division, glycogen metabolism, muscle contractility, protein synthesis, and HIV-1 viral transcription. Increased PP1 activity is detected in the end stage of heart failure. Studies in both human and mice suggest that PP1 is a significant regulator of cardiac function. Mouse studies also propose that PP1 functions as a suppressor of learning and memory.

Phospholipase A2 (PLA2) catalyzes the hydrolysis of the sn-2 position of membrane glycerophospholipids to liberate arachidonic acid (AA), a precursor of eicosanoids including prostaglandins and leukotrienes. The same reaction also produces lysophosholipids, which represent another class of lipid mediators.
The secretory PLA2 (sPLA2) family, in which 10 isozymes have been identified, consists of low molecular weight, Ca2+-requiring secretory enzymes that have been implicated in a number of biological processes, such as modification of eicosanoid generation, inflammation, and host defense.
This enzyme has been proposed to hydrolyze phosphatidylcholine (PC) in lipoproteins to liberate lyso-PC and free fatty acids in the arterial wall, thereby facilitating the accumulation of bioactive lipids and modified lipoproteins in atherosclerotic foci.
In mice, sPLA2 expression significantly influences HDL particle size and composition and demonstrate that an induction of sPLA2 is required for the decrease in plasma HDL cholesterol in response to inflammatory stimuli. Instillation of bacteria into the bronchi was associated with surfactant degradation and a decrease in large:small ratio of surfactant aggregates in rats.

EPCAM is a carcinoma-associated antigen and belongs to a family which includes at least 2 type I membrane proteins. The EPCAM protein has a role in embryonic stem cells proliferation and differentiation. EPCAM is used as a target for immunotherapy treatment of human carcinomas. EPCAM is expressed on most normal epithelial cells and gastrointestinal carcinomas and acts as a homotypic calcium-independent cell adhesion molecule. Epithelial cell adhesion molecules (EPCAM) can act as a physical homophilic interaction molecule between intestinal epithelial cells (IECs) and intraepithelial lymphocytes (IELs) at the mucosal epithelium for supplying immunological barrier as a first line of defense against mucosal infection. EPCAM gene mutations result in congenital tufting enteropathy.

IL-1Ra is the natural antagonist of the pro-inflammatory cytokines Interleukin-1? and Interleukin-1?. IL-1Ra is produced by a variety of cells including monocytes, macrophages, neutrophils and fibroblasts in response to the binding of various pro-inflammatory cytokines.