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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.

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).

Nucleobindin-2 (also known as NUCB2 or Nesfatin) is a EF-hand calcium-binding protein. Nucleobindin-2 takes part in calcium homeostasis and is a multifunctional protein that interacts with Ca(2+) nucleic acids & various regulatory proteins in different signaling pathways. NUCB2 (Nesfatin) is localized in neuronal perikarya and dendrites of mouse brain.

Adiponectin, also referred to as Acrp30, AdipoQ and GBP-28, is a recently discovered 244 amino acid protein, the product of the apM1 gene, which is physiologically active and specifically and highly expressed in adipose cells (Adipokine). The protein belongs to the soluble defense collagen super family; it has a collagen-like domain structurally homologous with collagen VIII and X and complement factor C1q-like globular domain. APM-1 forms homotrimers, which are the building blocks for higher order complexes found circulating in serum.

ADAM10 is part of the ADAM family which are cell surface proteins with a distinctive structure possessing both potential adhesion and protease domains. ADAM10 cleaves many proteins including TNF-alpha and E-cadherin. ADAM10 cleaves the membrane-bound precursor of tnf-alpha at 76- ala-|-val-77 to its mature soluble form. ADAM10 is in charge for the proteolytic release of several other cell-surface proteins, including ephrin-a2 and for constitutive and regulated alpha-secretase cleavage of amyloid precursor protein. ADAM10 is involved in the normal cleavage of the cellular prion protein. ADAM10 is involved in the cleavage of the adhesion molecule l1 at the cell surface and in the release of membrane vesicles, suggesting a vesicle-based protease activity. ADAM10 controls the proteolytic processing of notch and mediates lateral inhibition during neurogenesis.

SERPINA5 up regulates TAFI activation by inhibiting the protein C activation. SERPINA5 is a significant regulator in the equilibrium between coagulation and fibrinolysis by differentially inhibiting the activation of TAFI and of Protein-C. SERPINA5 belongs to the serpin serine proteinase inhibitor family. SERPINA5 protein inhibits plasminogen activators as well as activated protein C.
SERPINA5 is secreted in plasma & liver. SERPINA5 is involved in cell inflammation, proliferation, apoptosis, tumour cell migration, invasion, and metastasis. Moreover, SERPINA5 controls the invasive potential of renal cell carcinoma by inhibiting urinary plasminogen activator secreted by the cells. SERPINA5 participtes in regulating key serine proteases which are involved in metastatic prostate disease.

HPCAL1, participates in neuron-specific calcium-binding proteins family found in the retina and brain. HPCAL1 is extremely comparable to human hippocalcin protein and almost equal to the rat and mouse hippocalcin like-1 proteins. HPCAL1 takes part in the calcium-dependent regulation of rhodopsin phosphorylation and can have importance in neuronal signalling in the central nervous system.

Nectin Cell Adhesion Molecule 2, also known as NECTIN2, is a Ca(2+)-independent cell-cell adhesion molecule which is one of the plasma membrane components of adherens junctions. NECTIN2 takes a vital part in the establishment of homotypic as well as heterotypic cell to cell contacts. NECTIN2 is essential for resisting herpes simplex virus type 2 infection in transfected cells. NECTIN2 is also a possible target for antibody therapy of breast & ovarian cancers. NECTIN2 might be related with human longevity. Two diseases which have been associated with NECTIN2 are Herpes Simplex and Ovarian Cystic Teratoma.

ARL4A is related Specifically to ARL6 and ARL7 and belongs to the ARF-like protein (ARL) subfamily of small GTPases. However, unlike ARFs, ARL4 does not activate the cholera toxin ADP-ribosyltranferase. ARL4A takes part in neurogenesis during embryonic development and somitogenesis in the early stages of adult spermatogenesis.

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.

Chromosome 10 Open Reading Frame 54, also known as C10ORF54 is part of the immunoglobulin superfamily. Like a transmembrane molecule, C10ORF54 is expressed in the bone on embryonic stem cells (ESCs), and on tumor cell surface as well. Accordingly, C10ORF54 supports the differentiation of ESC and ehhances BMP4 induced signaling in ESC, however C10ORF54 is also down regulated following to BMP4 exposure.

Platelet Factor 4 Variant 1 (PF4V1) is a member of the intercrine alpha (chemokine CxC) family. PF4V1 is an inhibitor of angiogenesis and inhibitor of endothelial cell chemotaxis (in vitro).

CD68 encodes a 110-kD transmembrane glycoprotein that is highly expressed by human monocytes and tissue macrophages. It is a member of the lysosomal/endosomal-associated membrane glycoprotein (LAMP) family. The protein primarily localizes to lysosomes and endosomes with a smaller fraction circulating to the cell surface. It is a type I integral membrane protein with a heavily glycosylated extracellular domain and binds to tissue- and organ-specific lectins or selectins. The protein is also a member of the scavenger receptor family. Scavenger receptors typically function to clear cellular debris, promote phagocytosis, and mediate the recruitment and activation of macrophages. Alternative splicing results in multiple transcripts encoding different isoforms.

Cadherin 11 (CDH11) belongs to the cadherin superfamily (integral membrane proteins) which mediate calcium-dependent cell-cell adhesion. CDH11 is defined based on lacking a HAV cell adhesion recognition sequence specific to type I cadherins. CDH11 protein’s expression in osteoblastic cell lines, and its upregulation during differentiation, suggests a specific function in bone development and maintenance. CDH11 contributes to the sorting of heterogeneous cell types.

PSMB1 is part of the proteasome B-type family, also identified as the T1B family, that is a 20S core beta subunit. PSMB1 is tightly linked to the TBP (TATA-binding protein) gene in human and in mouse, and is transcribed in the opposite orientation in both species.The main function of PSMB1 is its degradation activity of unnecessary or damaged proteins by proteolysis. PSMB1 is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with arg, phe, tyr, leu, and glu adjacent to the leaving group at neutral or slightly basic ph. the proteasome has an atp-dependent proteolytic activity.

Vascular endothelial growth factor is an important signaling protein involved in both vasculogenesis and angiogenesis. As its name implies, VEGF activity has been mostly studied on cells of the vascular endothelium, although it does have effects on a number of other cell types (e.g. stimulation monocyte/ macrophagemigration, neurons, cancer cells, kidney epithelial cells ).VEGF mediates increased vascular permeability, induces angiogenesis, vasculogenesis and endothelial cell growth, promotes cell migration, and inhibits apoptosis. In vitro, VEGF has been shown to stimulate endothelial cell mitogenesisand cell migration. VEGF is also a vasodilator and increases microvascular permeability and was originally referred to as vascular permeability factor.
Elevated levels of this protein are linked to POEMS syndrome, also known as Crow-Fukase syndrome. Mutations in this gene have been associated with proliferative and nonproliferative diabetic retinopathy.

VEGF-C152S is a point mutant generated by the replacement of the second conserved Cys residue of the recombinant processed VEGF-C by a Ser residue. VEGF-C 152S is analog to the human VEGF-C 156S mutant and only active toward VEGFR-3/FLT-4 but, unlike wild type VEGF-C, is unable to bind to and to activate signaling through VEGFR-2/KDR. VEGF-C152S was inactive in the vascular permeability assay and did not increase migration of the capillary endothelial cells, indicating that these VEGF-like effects of VEGF-C require VEGFR-2 binding. VEGF-C, also known as Vascular Endothelial Growth Factor Related Protein (VRP), is a recently discovered VEGF growth factor family member that is most closely related to VEGF-D. The rat VEGF-C cDNA encodes a pre-pro-protein of 416 amino acids residues. It is almost identical to the mouse VEGF-C protein. Similar to VEGF-D, VEGF-C has a VEGF homology domain spanning the middle third of the precursor molecule and long N- and C-terminal extensions. In adults, VEGF-C is highly expressed in heart, placenta, ovary and small intestine. Recombinant rat VEGF-C, lacking the N- and C-terminal extensions and containing only the middle VEGF homology domain, forms primarily non-covalently linked dimers. This protein is a ligand for both VEGFR-2/KDR and VEGFR-3/FLT -4. Since VEGFR-3 is strongly expressed in lymphatic endothelial cells, it has been postulated that VEGF-C is involved in the regulation of the growth and/or differentiation of lymphatic endothelium. Although recombinant rat VEGF-C is also a mitogen for vascular endothelial cells, it is much less potent than VEGF-A.

RAB1B belongs to the RAB protein family, these proteins are low molecular mass monomeric GTPases localized on the cytoplasmic surfaces of distinct membrane bound organelles. RAB1B protein functions in the early secretory pathway and is essential for vesicle transport between the endoplasmic reticulum (ER) and Golgi.

Haptoglogin participates in intestinal permeability, permitting intercellular tight junction disassembly, and controlling the equilibrium among tolerance and immunity to non-self antigens. Haptoglobin has antibacterial activity and takes part in modulating many aspects of the acute phase response. Haptoglobin is processed to yield both alpha and beta chains, which later unite as a tetramer to produce haptoglobin. Haptoglobin binds free hemoglobin (Hb) secreted from erythrocytes In blood plasma with high affinity and thus inhibits its oxidative activity. Further, the haptoglobin-hemoglobin complex is being removed by the reticuloendothelial system.

VSNL1 is a member of the visinin/recoverin subfamily of neuronal calcium sensor proteins. VILIP1 is strongly expressed in granule cells of the cerebellum where it associates with membranes in a calcium-dependent manner and modulates intracellular signaling pathways of the central nervous system by directly or indirectly regulating the activity of adenylyl cyclase. Changes in cellular expression of VSNL1 were found in hipppocampi of schizophrenics, since more interneurons showed immunoreactivity.
VILIP1 is expressed in pancreatic beta-cells. VILIP1 elevation enhances insulin secretion in cAMP-associated manner. Down-regulation of VILIP-1 decreased cAMP accumulation but increased insulin gene transcription. VILIP-1 interacts with cell membrane and actin-based cytoskeleton. VSNL1 modulates cAMP-accumulation in C6 glioma cells. HLP3 modulates cGMP-accumulation in transfected neural cells and cerebellar granule neurons.

Based on sequence similarity to VEGF-A, a gene encoding a VEGF homologue has recently been discovered in the genome of Orf virus (OV) (Lyttle et al., 1994). Different isolates of Orf virus show significant amino acid sequence similarity to VEGF-A and described as a viral virulence factor that appears to be derived from captured host genes. All eight cysteine residues of the central cysteine knot motif characteristic of members of the VEGF family are conserved among other residues in the VEGF-E proteins (Dehio et al., 1999; Wise et al., 1999). Alignment of all mammalian VEGF sequences indicated that VEGF-E is distinct from the previously described VEGFs but most closely related to VEGF-A. Like VEGF-A, VEGF-E was found to bind with high affinity to VEGF receptor-2 (KDR) resulting in receptor autophosphorylation, whilst in contrast to VEGF-A, VEGF-E can not bind to VEGF receptor-1 (Flt-1). Furthermore VEGF-E can also not bind to VEGF receptor-3 (FLT-4). Therefore VEGF-E is a potent angiog

Mammalian crystallins which are water soluble structural proteins located in the vertebrate eye are classified in three forms, labeled alpha, beta and gamma. Crystallins, the primary components of the lens, raise the refractive index of the eye all through the accommodation by creating high-molecular weight aggregates that maintain transparency. CRYGS is a monomer that does not aggregate. CRYGS encodes the most substantial gamma-crystallin in adult eye lens tissue. Gamma-crystallins has a part in cataract formation due to aging or mutations in specific genes,

S100A1 is a member of the S100 family of calcium binding proteins with EF-hand type Ca+2 binding motive. S100A1 (Calcium Binding Protein A1) is involved in the activation of sarcoplasmatic calcium release and the regulation of intermediate filament polymerization. S100A1 may function in stimulation of Ca2+-induced Ca2+ release, inhibition of microtubule assembly, and inhibition of protein kinase C-mediated phosphorylation. Reduced expression of S100A1 has been implicated in cardiomyopathies.
S100 proteins are localized either in the cytoplasm or the nucleus of a wide range of cells. There are at least 13 members in the S100 gene family, which are located as a cluster on chromosome 1q21.

DCN1-like protein 2 (DCUN1D2) which contains one DCUN1 domain and 1 UBA-like domain, may have a role in the neddylation of cullins which regulate SCF-type ubiquitin ligase complexes. The gene encoding Dcun1D2 is located on human chromosome 13. Chromosome 13 contains major tumor suppressor genes, including BRCA2 and RB1, which are linked with breast cancer susceptibility and retinoblastoma, respectively.