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S100b is a member of the S100 family of proteins which are a family of EF-hand calcium binding proteins that exist mostly as dimers of the 20 currently identified individual S100 monomers. The S100B homodimer is expressed in cells of the central nervous system, glial cells and in certain peripheral cells e.g. Schwann cells, melanocytes, adipocytes and chondrocytes. S100 proteins are localized either in the cytoplasm or the nucleus of a wide range of cells. S100 proteins are involved in the regulation of a number of cellular processes such as cell cycle progression and differentiation. There are at least 13 members in the S100 gene family, which are located as a cluster on chromosome 1q21; however, S100b is located at 21q22.3. The determination of S100B in serum levels may be used to monitor the extent of brain injury and malignant melanoma. S100b proteins may have a role in Neurite extension, proliferation of melanoma cells, stimulation of Ca2+ fluxes, inhibition of PKC-mediated phosphorylation, astrocytosis and axonal proliferation, and inhibition of microtubule assembly. Chromosomal rearrangements and altered expression of the S100b gene are implicated in several neurological, neoplastic, and other types of diseases, including Alzheimer's disease, Down's syndrome, epilepsy, amyotrophic lateral sclerosis, melanoma, and type I diabetes.

Since April 2012, cases of the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) have been identified in various countries. Coronaviruses are the cause of the common cold, SARS (severe acute respiratory syndrome) and other severe illnesses with high mortality rates, all are classified into coronavirus family. MERS-CoV is a new type of SARS found in the coronavirus family causing severe pneumonia with sudden and serious respiratory illness with high mortality rates as well. Since January 27th 2015, the WHO has reported 956 human cases, including 351 deaths. More cases of the new coronavirus strain are expected. Like in other coronaviruses, large surface spike glycoprotein is a central structural protein of this virus; it is located above the virion surface to bind and enter into the target cell. Spike protein has 2 domains- S1 and S2. The S1 domain is responsible for cellular tropism and interaction with target cell, while the S2 domain is responsible for membrane fusion. The C-terminal of S1 domain contains a receptor binding domain, and is also a potential target for vaccine development and an antigen for diagnosis.

The signal sequence receptor (SSR) is a glycosylated endoplasmic reticulum membrane receptor related with protein translocation across the ER membrane. The SSR consists of 2 subunits, a 34-kD glycoprotein (alpha-SSR or SSR1) and a 22-kD glycoprotein (beta-SSR or SSR2). The human beta-signal sequence receptor gene (SSR2) maps to chromosome bands 1q21-q23. Diseases correlated with SSR2 include calcaneonavicular coalition, and osteosarcoma, and among its related super-pathways are Viral mRNA Translation and Generic Transcription Pathway.

The La protein is a 47 kDa polypeptide that frequently acts as an autoantigen in systemic lupus erythematosus and Sjogren's syndrome patients. La is involved in various aspects of RNA metabolism, including binding and protecting 3-prime UUU(OH) elements of newly RNA polymerase III - transcribed RNA, processing 5-prime and 3-prime ends of pre-tRNA precursors, acting as an RNA chaperone, and binding viral RNAs linked to hepatitis C virus. It occurs in both the nucleus and the cytoplasm, where it assumes different roles. In the nucleus, La protein facilitates the production of tRNAs, acting as an RNA polymerase III (RNAP III) transcription factor by attaching to the U-rich 3'UTR of nascent transcripts, aiding in their folding and maturation. In the cytoplasm, La protein facilitates the translation of specific mRNAs, acting as a translation factor. As an RNA binding protein (RBP), La protein associates with subsets of mRNAs which contain a 5'-terminal oligopyrimidine (5'TOP) motif known to direct protein synthesis. The binding of La protein to particular classes of RNA molecules regulates their downstream processing, guards them from endonuclease digestion, and organizes their export from the nucleus. La/SS-B appears to be readily disposed to proteolysis, which results in many smaller (42kD, 320, and 270) nevertheless still immunoreactive polypeptides. La/SS-B antigen is strongly conserved across species. Anti-La/SS-B autoantibodies were originally found as precipitating autoantibodies in sera of Sjogren's Syndrome patients and referred to as SjT. Anti-La/SS-B precipitins are most frequently found in Sjogren's Syndrome, Systemic Lupus Erythematosus (SLE) and Subacute Cutaneous Lupus. Also, there seems to be a correlation between anti-La/SS-B and the absence of nephritis in SLE patients.

Fibrinogen silencer-binding protein (FSBP), interacts with X11alpha. The X11alpha/FSBP complex send signals to the nucleus in order to repress glycogen synthase kinase-3beta promoter activity. X11alpha is a neuronal adaptor protein that interacts with the amyloid precursor protein (APP) via a centrally located phosphotyrosine binding domain to inhibit the production of Abeta peptide that is deposited in Alzheimer's diseased brains.

PC4 and SFRS1 Interacting Protein 1 (PSIP1) is a transcriptional coactivator involved in neuroepithelial stem cell differentiation and neurogenesis. PSIP1 is also involved particularly in lens epithelial cell gene regulation and stress responses. PSIP1 has a significant role in lens epithelial to fiber cell terminal differentiation. In addition, PSIP1 plays a protective role during stress-induced apoptosis. Furthermore, PSIP1 is a cellular cofactor for lentiviral integration.

Persephin is a member of the GDNF ligand subfamily of the TGF-beta superfamily. PSPN encourages the existence and growth of key dopaminergic and motor neurons, as well as taking part in kidney development. Nonetheless, persephin does not support existence of peripheral neurons.

HSPB7 is part of the Heat shock protein beta family. The HSPB family is one of the more diverse families within the group of HSP families. Several members have chaperone-like activities and/or participate in cytoskeletal stabilization. Several members also show a dynamic, stress-induced translocation to SC35 splicing speckles. HSPB7 constitutively localized to SC35 splicing speckles, determined by its N-terminus. HSPB7 does not support refolding though HSPB1 and HSPB5 chaperone heat unfolded substrates and keet them folding competent.

Methionine sulfoxide reductase B (MsrB) from Escherichia coli is a member of the msrB Met sulfoxide reductase family. The E.coli msrB carries out the reduction of methionine-R-sulfoxide to methionine. msrB possess a metal binding site composed of 2 CXXC motifs. The bound metal (zinc or iron) may stabilize the conformation of the enzymes.

SPG21 binds to the hydrophobic C-terminal amino acids of CD4 which take part in suppression of CD-4 dependant T cell activation. The interaction with CD4 is mediated by the noncatalytic alpha/beta hydrolase fold domain. SPG21 adapts the stimulatory activity of CD4. SPG21 is broadly expressed in diverse tissues including heart, brain, placenta, lung, liver, skeletal muscle, kidney and pancreas. Mutations in SPG21 cause Mast syndrome, an autosomal-recessive complicated form of hereditary spastic paraplegia characterized by dementia, thin corpus callosum and white matter abnormalities.

SF3B14 is a 125 amino acid nuclear protein which is a component of the splicing factor 3b complex. Splicing factor 3b is involved with s with both the U2 and U11/U12 small nuclear ribonucleoprotein complexes (U2 snRNP) of spliceosomes. SF3B14 which is required for the splicing of pre-mRNA enters the spliceosome and connect with the pre-mRNA branch site facilitating the interaction of snRNP with the branch sites of U2 and U12 of the 17S U2 and the 18S U11/U12 snRNP complex.

SBDS is part of an extremely preserved protein family which exists from archaea to vertebrates and plants. SBDS protein functions in RNA metabolism and has a role in the biogenesis of the 60S ribosomal subunit and translational activation of ribosomes. Shwachman-Diamond syndrome is a rare autosomal recessive disorder produced by mutations in the SBDS gene.

SecB, a significant chaperone that takes part in protein export, binds various ligands rapidly with high affinity and low specificity. SecB plays an important role during protein export through the general secretory pathway by modulating the partitioning of precursors between folding or aggregation and delivery to the membrane-bound translocation apparatus. SecB has the potential to take part in functions outside of export acting as a universal nonspecific chaperone to provide buffering capacity of the nonnative state of proteins in the cytosolic pool.

HBsAg is the surface antigenof the Hepatitis-B-Virus (HBV). The capsidof a virus has different surface proteins from the rest of the virus. The antigen is a protein that binds specifically on one of these surface proteins. It is commonly referred to as the Australian Antigen.

HSPB3 is a muscle-specific small heat shock protein which is expressed specially in heart and skeletal muscle. Mammalian small heat shock proteins (sHSP) are highly expressed proteins with varied roles, including the assembly and impounding of multi-protein complexes, transportation of nascent polypeptide chains thru cellular membranes and regulation of protein folding. HSPB3 perform as an ATP-dependent chaperone protein which takes part in the refolding of denatured proteins and inhibition of actin polymerization.

SUGT1 is homolog to yeast protein SGT1, a regulator of the cell cycle which is vital for G1/S and G2/M transitions. SUGT1 holds a CS domain, a SGS domain, a p23 domain and three tetratricopeptide repeats (TPR). SUGT1 protein associates with Skp1 p19 and CUL-1, subunits of the SCF ubiquitin ligase complex, and is believed to take a part in protein degradation. Furthermore, SUGT1 is essential for the kinetochores assembly, and has a role as a co-chaperone for HSP90.

PSMA is a cancer antigen that is widely expressed as a noncovalent homodimer on the surface of prostate cancer cells, rather than on normal cells, therefore it is an interesting target to image prostate tissues when being used with radioactive antibodies. PSMA is expressed on the surface of novel blood vessels that nourish a broad range of other solid tumors. PSMA is a type II membrane protein with folate hydrolase activity produced by prostatic epithelium. PSMA expression is found in extraprostatic tissues, including small bowel and brain.

FARSB, also known as Phenylalanyl-TRNA Synthetase Beta is a member of the phenylalanyl-tRNA synthetase beta subunit family. FARSB is composed tetramer of two alpha and two beta subunits. In the presence of ATP, this tetramer is accountable for attaching L-phenylalanine to the terminal adenosine of the appropriate tRNA.

SBDS is part of an extremely preserved protein family which exists from archaea to vertebrates and plants. SBDS protein functions in RNA metabolism and has a role in the biogenesis of the 60S ribosomal subunit and translational activation of ribosomes. Shwachman-Diamond syndrome is a rare autosomal recessive disorder produced by mutations in the SBDS gene.

Serine/arginine-rich splicing factor 1 (SFRS1) belongs to the arginine/serine-rich splicing factor protein family, and functions in both constitutive and alternative pre-mRNA splicing. SFRS1 binds to pre-mRNA transcripts and components of the spliceosome, and can either initiate or inhibit splicing depending on the position of the pre-mRNA binding site. The ability of SFRS1 to activate splicing is controlled by phosphorylation and interactions with other splicing factor associated proteins.

Persephin is a member of the GDNF ligand subfamily of the TGF-beta superfamily. PSPN encourages the existence and growth of key dopaminergic and motor neurons, as well as taking part in kidney development. Nonetheless, persephin does not support existence of peripheral neurons.

S100b is a member of the S100 family of proteins which are a family of EF-hand calcium binding proteins that exist mostly as dimers of the 20 currently identified individual S100 monomers. The S100B homodimer is expressed in cells of the central nervous system, glial cells and in certain peripheral cells e.g. Schwann cells, melanocytes, adipocytes and chondrocytes. S100 proteins are localized either in the cytoplasm or the nucleus of a wide range of cells. S100 proteins are involved in the regulation of a number of cellular processes such as cell cycle progression and differentiation. There are at least 13 members in the S100 gene family, which are located as a cluster on chromosome 1q21; however, S100b is located at 21q22.3. The determination of S100B in serum levels may be used to monitor the extent of brain injury and malignant melanoma. S100b proteins may have a role in Neurite extension, proliferation of melanoma cells, stimulation of Ca2+ fluxes, inhibition of PKC-mediated phosphorylation, astrocytosis and axonal proliferation, and inhibition of microtubule assembly. Chromosomal rearrangements and altered expression of the S100b gene are implicated in several neurological, neoplastic, and other types of diseases, including Alzheimer's disease, Down's syndrome, epilepsy, amyotrophic lateral sclerosis, melanoma, and type I diabetes.