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Junctional Adhesion Molecule 2 (JAM2) is a member of the immunoglobulin superfamily, and the junctional adhesion molecule (JAM) family. JAM2 is a type I membrane protein which is localized at the tight junctions of both epithelial and endothelial cells. JAM2 functions as an adhesive ligand for interacting with various immune cell types, and may have a role in lymphocyte homing to secondary lymphoid organs.

TNFR2 belongs to the TNF-receptor superfamily. TNFR2 is receptor with high affinity for TNFSF2/TNF-alpha and approximately 5-fold lower affinity for homotrimeric TNFSF1/lymphotoxin-alpha. TNFR2 mediates the majority of the metabolic effects of TNF-alpha. In addition, knockout studies in mice propose a role for TNFR2 in protecting neurons from apoptosis by stimulating antioxidative pathways. TNFR2 expression might have a significant role in the angiogenesis, tumor cell proliferation and metastasis of Invasive micropapillary carcinoma of the breast.
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. High levels of soluble TNF receptors are found in the amniotic fluid of pregnant women. TNFR2 and TNFR1 form a heterocomplex which mediates the recruitment of 2 anti-apoptotic proteins, c-IAP1 and c-IAP2, which possess E3 ubiquitin ligase activity. IAPs’ function in TNF-receptor signaling is unknown; nevertheless, c-IAP1 is believed to potentiate TNF-induced apoptosis by the ubiquitination and degradation of TNF-receptor-associated factor 2, which mediates anti-apoptotic signals. Oxidative stress promotes TNFR1 and TNFR2 self-interaction, ligand-independent and enhanced ligand-dependent TNF signaling. TNF-a, TNFR1 and TNFR2 have roles in cellular differentiation. TNFR1 and TNFR2 function in cell type-specific renal injury.

SPINT2 is a transmembrane protein acts as an inhibitor of HGF activator. SPINT2 inhibits plasmin, plasma and tissue kallikrein, and factor XIa. SPINT2 has two extracellular Kunitz domains that inhibit few serine proteases. SPINT2 is assumed tumor suppressor, mutations in SPINT2 leads to a congenital sodium diarrhea.

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.

TAFA-2 is a 11 kDa secreted protein that belongs to the FAM19/TAFA family of chemokine-like proteins. Similar to other FAM19/TAFA family members, mature TAFA-1 contains 10 regularly spaced cysteine residues with the same pattern: CX7CCX13CXCX14CX11CX4CX5CX10C (C symbolizes a conserved cysteine residue and X symbolizes any noncysteine amino acid). Human TAFA-2 is 97% aa identical to mouse TAFA-2 and is expressed in the central nervous system (CNS), colon, heart, lung, spleen, kidney, and thymus, however its expression in the CNS is 50 to 1000 fold higher than in other tissues. The biological roles of TAFA family members have not yet been determined.

MYL2 regulatory light chain is associated with cardiac myosin beta (or slow) heavy chain. Ca+ activates the phosphorylation of regulatory light chain that in turn activates contraction. Mutations in this MYL2 gene are related with mid-left ventricular chamber type hypertrophic cardiomyopathy. MYL2 is an essential protein that plays a role in the regulation of myosin ATPase activity in smooth muscle. MYL2 phosphorylation is regulated by ROCK and MLC kinase and is involved in platelet biogenesis by controlling proplatelet formation and fragmentation.

IL1R2 is a cytokine receptor which is a part of the interleukin-1 receptor family. IL1R2 is expressed mainly by T cells, endothelial cells and fibroblasts. IL1R2 binds IL1A, IL1B and IL1RN preventing them from binding to their regular receptors and thus inhibiting the transduction of their signaling. Also, Interleukin-4 antagonizes the activity of interleukin-1 by inducing the expression and release of this protein.

HTATIP2 is part of the short-chain dehydrogenases/reductases (SDR) family which acts as a tumor suppressor in metabolic suppression, inhibition of angiogenesis and induces the expression of apoptosis related genes Bad and Siva. HTATIP2 cooperates with the activation domain of HIV-1 TAT and enhances its transcription by phosphorylating RNA polymerase II (Pol II). Defects in HTATIP2 are related with hepatocellular carcinomas and apoptotic resistant tumor cells, implicating a probable use for HTATIP2 in antitumor therapy.

Mesoderm development candidate 2 (MESDC2) is required for formation of the primitive streak and mesoderm during embryogenesis. MESDC2 binds to the Wnt co-receptors LRP5 and LRP6 in the endoplasmic reticulum and is required for their proper folding and cell surface expression.

The Casein kinase 2 (EC 2.7.11.1) is a serine/threonine-selective protein kinase that is a tetramer of two alpha subunits and two beta subunits. The alpha subunits have the catalytic kinase domain. Casein kinase 2 has been implicated in cell cycle control, DNA repair, regulation of the circadian rhythm and other cellular processes. Casein kinase 2 activity has been reported to be activated following Wnt signaling pathway activation. A Pertussis toxin-sensitive G protein and Disheveled appear to be an intermediary between Wnt-mediated activation of the Frizzled receptor and activation of casein kinase 2. Mice that lack casein kinase 2 alpha prime have a defect in the morphology of developing sperm.

GTF2E2 is vital for transcription initiation by RNA polymerase II in conjunction with other general factors. General Transcription Factor IIE is a heterotetramer composed of two subunits of relatively high molecular mass 57,000 (GTF2E1) and two of 34,000 (GTF2E2). GTF2E2 is necessary in conjunction with GTF2E1 for transcription initiation. GTF2E2 recruits TFIIH to the initiation complex and stimulates the RNA polymerase II C-terminal domain kinase and DNA-dependent ATPase activities of TFIIH. Both TFIIE and TFIIH are essential for promoter clearance by RNA polymerase.

Defensins are cationic peptides with a large spectrum of antimicrobial activity that comprise an important arm of the innate immune system. The Alpha defensins are differentiated from the Beta-defensins by the pairing of their 3 disulfide bonds.
4 human Beta-defensins have been identified to date; BD-1, BD-2, BD-3 and BD-4.
Beta-defensins are expressed on some leukocytes and at epithelial surfaces.
In addition to their direct antimicrobial activities, they are chemoattractant towards immature dendritic cells and memory T cells. The beta-defensin proteins are expressed as the C-terminal portion of precursors and are released by proteolytic cleavage of a signal sequence and, in the case of BD-1 (36 a.a.), a propeptide region. Beta-defensins contain a six-cysteine motif that forms three intra-molecular disulfide bonds. Beta-Defensins are 3-5 kDa peptides ranging in size from 33-47 amino acid residues.

Stromal Cell-Derived Factor 2 (SDF2) is a secretory protein which is partly similar to the hydrophilic segments of yeast mannosyltransferases. SDF2 protein’s expression is ubiquitous and the gene is rather conserved among mammals. SDF2 is a protein-coding gene whose alternative splicing results in coding and non-coding variants.

F-Box Protein 2 (FBXO2) is a part of the F-box protein family. The F-box proteins are one of the 4 subunits of the ubiquitin protein ligase complex called SCFs (SKP1-cullin-F-box), which takes part in phosphorylation-dependent ubiquitination. The F-box proteins are divided into 3 classes. FBXO2 belongs to the Fbxs class which contains either different protein-protein interaction modules or no recognizable motifs. FBXO2 is extremely similar to the rat neural F Box 42 kDa protein which is enriched in the nervous system and plays a role in maintaining neurons in a postmitotic state.

Succinate Dehydrogenase Complex Assembly Factor 2 (SDHAF2) is a mitochondrial protein required for the flavination of a succinate dehydrogenase complex subunit essential for activity of the complex. DHAF2 is necessary for insertion of FAD cofactor into SDHA, the catalytic subunit of succinate dehydrogenase (SDH). SDH is involved in complex II of the mitochondrial electron transport chain and is responsible for transferring electrons from succinate to ubiquinone (coenzyme Q). SDHAF2 gene defects are the cause of hereditary paragangliomas type 2 (PGL2), otherwise known as familial non-chromaffin paragangliomas type 2.

Synaptobrevin 2 which is an 18 kDa integral membrane protein localized to the cytoplasmic surface of synaptic vesicle, consists of a proline-rich N-terminal region, a highly conserved hydrophilic domain, followed by a transmembrane anchor and a C-terminal. Synaptobrevin 2 is predominantly expressed in Langerhans islets and glomerular cells. The N-terminal domain of the protein (residues 1-89) forms a specific SNARE complex with the target membrane-associated t- or Q-SNAREs syntaxin 1 and SNAP-25.

Fibrinogen Beta Chain 9 (FGB) is the beta component of fibrinogen, a blood-borne glycoprotein composed of 3 pairs of nonidentical polypeptide chains. When vascular injury accrues, fibrinogen is cleaved by thrombin to form fibrin which is found in abundance in blood clots.

CD2 which is also known as E-rosette receptor, T11 and lymphocytefunction antigen-2 (LFA-2) is expressed on T cells, thymocytes, and subset of natural killer cells. Human CD2 functions as the receptor for sheep erythrocytes, human CD58 (LFA-3), and CD15s (Sialyl Lewis X). p56lck, p59fyn, CD3eta and CD3epsilon are tyrosine-phosphorylated after CD2 stimulation. CD2 plays a role in T cell activation, T- or NK-cell-mediated cytolysis, apoptosis in activated peripheral T cells, and regulation of T cell anergy.

Eotaxin-2, also called MPIF2 & Ckb6, is a novel CC chemokine produced by activated monocytes and T lymphocytes. Eotaxin-2 selectively chemoattracts cells expressing CCR3 including eosinophils, basophils, Th2 T cells, mast cells, and certain subsets of dendritic cells. Furthermore, Eotaxin-2 inhibits the proliferation of multipotential hematopoietic progenitor cells. The mature protein, which includes C-terminal truncation, contains 78 amino acids (92 amino acids for the mouse homolog, without C-terminal truncation).
CCL24 functions as a chemotactic chemokine for resting t-lymphocytes, and eosinophils. CCL24 has lower chemotactic activity for neutrophils but none for monocytes and activated lymphocytes. CCL24 is a strong suppressor of colony formation by a multipotential hematopoietic progenitor cell line and binds to CCR3.

Chemokine (C-X-C motif) ligand (CXCL7) is a small cytokine belonging to the CXC chemokine family. It is a protein that is released in large amounts from platelets following their activation. It stimulates various processes including mitogenesis, synthesis of extracellular matrix, glucose metabolism and synthesis of plasminogen activator.

LGALS2 is a soluble beta-galactoside binding lectin that controls cell-to-cell adhesion and cell-to-extracellular matrix interactions and takes part in tumor progression, pre-mRNA splicing and apoptosis. LGALS2 induces apoptosis in activated T cells and binds to the cytokine lymphotoxin-alpha (LTA) with threat of myocardial infarction.

Ro 60 kDa autoantigen is an RNA-binding protein that binds to several small cytoplasmic RNA molecules known as Y RNAs. SSA2 may stabilize these RNAs from degradation. Sera taken from patients with Systemic Lupus Erythematosus (SLE) often contains antibodies that react with the normal cellular SSA2 protein as if this antigen was foreign.

b-synuclein (amino acids 1-134), an acidic neuronal protein of 134 amino acids, is extremely heat-resistant. b-synucelin also has a chaperone-like activity. Recently, b-synuclein has been suggested to inhibit a-synuclein aggregation. b and a-synuclein are abundantly expressed in the brain and putatively inhibit phospholipase D2 selectively. The encoded protein, which may play a role in neuronal plasticity, is abundant in neurofibrillary lesions of patients with Alzheimer disease.

MGAT2 is an enzyme which takes part in the catalyzation of a crucial step in the reaction of oligomannose which converts to complex N-glycans. MGAT2 has three domains, classic to glycosyltransferase: short N-terminal cytoplasmic domain, a C-terminal catalytic domain and hydrophobic non-cleavable signal-anchor domain. The enzyme MGAT2 is encoded by the MGAT2 gene in humans. There are no introns in the DNA coding the gene, therefore mutations in the MGAT2 will result in carbohydrate-deficient glycoprotein syndrome, type II.