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Cathepsins B, C, H, L, S, V, X/Z/P and 1 are cysteine proteases of the papain family. Cathepsin C is also known as DPPI (dipeptidyl-peptidase I). Cathepsin A is a serine carboxypeptidase and Cathepsin D and E are aspartic proteases. As lysosomal proteases, cathepsins play an important role in protein degradation. Because of their redistribution or increased levels in human and animal tumors, cathepsins may have a role in invasion and metastasis. Cathepsins are synthesized as inactive proenzymes and processed to become mature and active enzymes. Endogenous protein inhibitors, such as cystatins and some serpins, inhibit active enzymes.

Entry of HSV into the host cell involves interactions of several viral glycoproteins with cell surface receptors. The virus particle is covered by an envelope which, when bound to specific receptors on the cell surface, will fuse with the cell membrane and create an opening, or pore, through which the virus enters the host cell. The sequential stages of HSV entry are analagous to those of other viruses. At first, complementary receptors on the virus and cell surface bring the two membranes into proximity. In an intermediate state, the two membranes begin to merge, forming a hemifusion state. Finally, a stable entry pore is formed through which the viral envelope contents are introduced to the host cell.

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.

High-mobility group box 1 protein (HMGB1), previously known as HMG-1 or amphoterin, is a member of the high mobility group box family of non-histone chromosomal proteins. Human HMGB1 is expressed as a 30 kDa, 215 amino acid (aa) single chain polypeptide containing three domains: two N-terminal globular, 70 aa positively charged DNA-binding domains (HMG boxes A and B), and a negatively charged 30 aa C-terminal region that contains only Asp and Glu.4, 5 Residues 27 - 43 and 178 - 184 contain a NLS. Posttranslational modifications of the molecule have been reported, with acetylation occurring on as many as 17 lysine residues. HMGB1 is expressed at high levels in almost all cells. It was originally discovered as a nuclear protein that could bend DNA. Such bending stabilizes nucleosome formation and regulates the expression of select genes upon recruitment by DNA binding proteins.

Serine/threonine-protein kinase 16 (STK16) is a membrane-associated protein kinase which phosphorylates on serine and threonine residues. STK16 is involved in secretory vesicle trafficking or intracellular signaling. Furthermore, the STK16 protein may have a role in regulating stromal-epithelial interactions which occur during ductal morphogenesis in the mammary gland. STK16 can autophosphorylate on Tyr residue; it is however unclear whether STK16 has tyrosine-protein kinase toward other proteins. STK16 may also be involved in TGF-beta signaling.

SHMT1 is a member of the SHMT family. SHMT1 is the cellular form of serine hydroxymethyltransferase, a pyridoxal phosphate-containing enzyme which catalyzes the reversible conversion of serine and tetrahydrofolate to glycine and 5 10-methylene tetrahydrofolate. In addition, SHMT1 specifically provides one-carbon units for thymidylate biosynthesis, reduces methylenetetrahydrofolate pools for S-adenosylmethionine (SAM) synthesis by synthesizing serine, sequesters 5-methyltetrahydrofolate and inhibits SAM synthesis.

HPRT1 has a main part in the generation of purine nucleotides through the purine salvage pathway. HPRT1 primarily functions to salvage purines from degraded DNA to renewed purine synthesis. Therefore, it performs as a catalyst in the reaction between guanine and phosphoribosyl pyrophosphate to form GMP.

Noroviruses are categorized into two groups - group 1 and group 2. Norovirus is a widespread virus which can cause human gastroenteritis, an illness characterized with symptoms such as abdominal pain, diarrhea, vomiting and sickness. In America there are about 20 million causes of infection by Nororvirus, 800 ending in deaths. Worldwide, this virus infects around 267 million people and causes over 200,000 deaths per year. Even though having norovirus is unpleasant, it is seldom dangerous and typically ends in full recovery after few days. The cases resulting in deaths are primarily very young, elderly and immuno-suppressed individuals and people from less developed countries. Norovirus is extremely contagious and is spread from person to person, by infected food or water or polluted surfaces. Outbreaks usually happen from November to April, peaking in January.

SNTA1 is a member of the syntrophin gene family. SNTA1 is a peripheral membrane protein found linked with dystrophin and dystrophin-related proteins. Dystrophin is a large, rod-like cytoskeletal protein located at the inner surface of muscle fibers. Dystrophin is absent in Duchenne Muscular Dystrophy patients, however it is present in reduced amounts in Becker Muscular Dystrophy patients. Syntrophins are cytoplasmic peripheral membrane scaffold proteins and components of the dystrophin-associated protein complex. The N-terminal PDZ domain of SNTA1 interacts with the C-terminus of the pore-forming alpha subunit (SCN5A) of the cardiac sodium channel Nav1.5. In addition, SNTA1 associates cardiac sodium channels with the nitric oxide synthase-PMCA4b (plasma membrane Ca-ATPase subtype 4b) complex in cardiomyocytes. The SNTA1 gene is a predisposition locus for Long-QT syndrome (LQT) - an inherited disorder associated with sudden cardiac death from arrhythmia - and sudden infant death syndrome (SIDS). SNTA1 also associates with dystrophin and dystrophin-related proteins at the neuromuscular junction and modifies intracellular calcium ion levels in muscle tissue.

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.

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.

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.

MCM7 is a highly conserved mini-chromosome maintenance protein (MCM) vital for eukaryotic genome replication initiation. The MCM proteins form a hexameric protein complex which is a key component of the pre-replication complex (pre_RC) which takes part in replication forks formation and in DNA replication related proteins recruitment. The MCM complex is comprised of MCM2, 4, 6 and 7 proteins and possesses DNA helicase activity, such as DNA unwinding.

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 is caused by a human coronavirus. Human coronaviruses are the major cause of upper respiratory tract illness in humans, such as the common cold. 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 most prominent protein in the culture supernatants infected with SARS virus is a 46 kDa nucleocapsid protein. This suggests that the nucleocapsid protein is a major immunogen that may be useful for early diagnostics.

MOG is a membrane protein expressed on the oligodendrocyte cell surface and the outermost surface of myelin sheaths. Due to this localization, it is a primary target antigen involved in immune-mediated demyelination. MOG is involved in completion and maintenance of the myelin sheath and in cell-cell communication. Alternatively spliced transcript variants encoding different isoforms have been identified Minor component of the myelin sheath is involved in completion and/or maintenance of the myelin sheath and in cell- cell communication.

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 is caused by a human coronavirus. Human coronaviruses are the major cause of upper respiratory tract illness in humans, such as the common cold. 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 most prominent protein in the culture supernatants infected with SARS virus is a 46 kDa nucleocapsid protein. This suggests that the nucleocapsid protein is a major immunogen that may be useful for early diagnostics.

MVK is a member of the GHMP kinase family. Mevalonate is a vital mediator, and MVK an important early enzyme, in isoprenoid and sterol synthesis. MVK deficiency can result in gene mutation associated with Mevalonic aciduria, an illness which causes psychomotor retardation, failure to thrive hepatosplenomegaly, anemia and frequent febrile crises. Mutations in this gene also cause hyperimmunoglobulinaemia D and sporadic fever syndrome, in which the person suffers from recurrent episodes of fever related with lymphadenopathy, skin rash, gastrointestinal dismay and arthralgia.

GH is a member of the somatotropin/prolactin family of hormones which play an important role in growth control. The gene, along with four other related genes, is located at the growth hormone locus on chromosome 17 where they are interspersed in the same transcriptional orientation; an arrangement which is thought to have evolved by a series of gene duplications. The five genes share a remarkably high degree of sequence identity. Alternative splicing generates additional isoforms of each of the five growth hormones, leading to further diversity and potential for specialization. This particular family member is expressed in the pituitary but not in placental tissue as is the case for the other four genes in the growth hormone locus. Mutations in or deletions of the gene lead to growth hormone deficiency and short stature.

Sarcoglycan Delta (SGCD) is one of the four known components of the sarcoglycan complex, which is a subcomplex of the dystrophin-glycoprotein complex (DGC) and is expressed mainly in skeletal and cardiac muscle. DGC forms a link between the F-actin cytoskeleton and the extracellular matrix. SGCD protein’s mutations have been associated with autosomal recessive limb-girdle muscular dystrophy and dilated cardiomyopathy. SGCD gene expression is regulated by MITF In melanocytic cells.

ST13 is an adaptor protein (co-chaperone) that mediates the association of HSP70 & HSP90 and appears in early receptor complexes. ST13 plays a role in the assembly process of glucocorticoid receptor, which requires the assistance of multiple molecular chaperones. The expression of ST13 is downregulated in colorectal carcinoma tissue signifying that is candidate tumor suppressor gene. Through common binding to both Hsp70 and Hsp90, ST13 functions as an adaptor that can integrate Hsp70 and Hsp90 interactions. The expression of ST13 decreases in colorectal cancer tissue compared with that in adjacent normal tissue. ST13 is mostly expressed in colorectal epithelia and adenocarcinoma cells. ST13 functions to promote the efficiency of glucocorticoid receptor maturation in cells. The expression levels of the ST13 gene were significantly decreased in primary tumors compared with adjacent mucosa.

Basic fibroblast growth factor is a member of the fibroblast growth factor (FGF) family. FGF family members possess broad mitogenic and cell survival activities, and are involved in a variety of biological processes, including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth and invasion. This protein functions as a modifier of endothelial cell migration and proliferation, as well as an angiogenic factor. It acts as a mitogen for a variety of mesoderm- and neuroectoderm-derived cells in vitro, thus is thought to be involved in organogenesis. Three alternatively spliced variants encoding different isoforms have been described. The heparin-binding growth factors are angiogenic agents in vivo and are potent mitogens for a variety of cell types in vitro. There are differences in the tissue distribution and concentration of these 2 growth factors.