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Dsb proteins are in charge for the formation and rearrangement of disulfide bonds during the folding of secreted and membrane proteins in bacteria. DsbG has disulfide bond isomerase and chaperone activity. DsbG interacts with refolding intermediates of chemically denatured citrate synthase and prevents their aggregation in vitro. DsbG shares sequnce homology with DsbC. DsbG forms a stable periplasmic dimer and displays an equilibrium constant with glutathione comparable with DsbA and DsbC. DsbG is expressed at roughly 25% level of DsbC.

The 26S proteasome is a multicatalytic proteinase complex with a well ordered structure composed of two complexes- a 20S core and a 19S regulator. PSMD11 is a non-ATPase subunit of the 19S regulator. The 20S core is composed of four rings of 28 non-identical subunits; two rings are composed of 7 alpha subunits and two rings are composed of 7 beta subunits. The 19S regulator is composed of a base that contains six ATPase subunits and two non-ATPase subunits, and a lid that contains up to ten non-ATPase subunits. Proteasomes are spread throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An indispensable function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides.

E-selectin which is also called Endothelial leukocyte adhesion molecule 1, ELAM1, ELAM belongs to a family of divalent cation-dependent carbohydrate-binding glycoproteins or adhesion molecules. Eselectin is expressed on the surface of endothelial cells and mediates the interaction of leukocytes and platelets with endothelial cells during an inflammatory response. E-selectin is present in single copy in the human genome and contains 14 exons spanning about 13 kb of DNA.

Recombinant Human Sonic Hedgehog is part of a small group of secreted proteins that are vital for development in both vertebrates and invertebrates. 3 mammalian hedgehog genes (sonic, desert, Indian) share about 60% homology. The Human Sonic Hedgehog is 99% homologous to the mouse gene. Sonic HedgeHog is a protein that is vital in guding the early embryo. It has been associated as the major inductive signal in patterning of the ventral neural tube, the anterior-posterior limb axis, and the ventral somites. Sonic HedgeHog binds to the patched receptor, which functions in association with smoothened, to activate the transcription of target genes. In the absence of sonic HedgeHog, patched receptor represses the constitutive signaling activity of smoothened. Sonic HedgeHog also regulates another factor, the gli oncogene. Sonic HedgeHog intercellular signal is essential for a various patterning events during development: signal produced by the notochord that induces ventral cell fate in the neural tube and somites, and the polarizing signal for patterning of the anterior-posterior axis of the developing limb bud. Sonic HedgeHog exhibits both floor plate- and motor neuron-inducing activity. Mutations in a long-range Sonic HedgeHog enhancer located in an intron of the limb region 1 gene result in preaxial polydactyly.

Pleiotrophin (Osteoblast-Specific Factor-1, OSF-1) contains 136 amino acid residues. The sequence is very rich in cationic amino acids (24% of the residues); lysine cluster sequences are found in the N-terminal and C-terminal ends of the structure.
The OSF-1 gene was shown by Northern blotting analysis to be expressed in mouse calvarial osteoblast-enriched cells and in mouse brain tissues, but not in thymus, spleen, kidney, liver, lung, testis or heart. Pleiotrophin has the ability to promote adhesion, migration, expansion, and differentiation of human osteoprogenitor cells. In addition to certain types of cancer, the embryonic growth and differentiation factor pleiotrophin is found also in adults in inflammatory diseases. In osteoarthritis, pleiotrophin is especially expressed in early stages, and its concentrations in the synovial fluid could serve as a marker for the progress of the disease. Pleitrophin might be involved in cartilage repair in osteoarthritis, in particular, in earlier stages.

SLC3A2, also known as Solute Carrier Family 3 Member 2, is a single-pass type II membrane protein which is part of the SLC3A transporter family. SLC3A2 is expressed ubiquitously in all tissues tested with the highest levels detected in kidney, placenta and testis and lowest level in thymus. SLC3A2 is essential for the function of light chain amino-acid transporters and also takes part in sodium-independent, high-affinity transport of large neutral amino acids such as phenylalanine, tyrosine, leucine, arginine and tryptophan. SLC3A2 participates in guiding and targeting of LAT1 and LAT2 to the plasma membrane.

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).

STAM Binding Protein Like 1 (STAMBPL1) is a zinc metalloprotease which specifically cleaves 'Lys-63'-linked polyubiquitin chains, however, it doesn’t cleave 'Lys-48'-linked polyubiquitin chains. STAMBPL1 binds 2 zinc ions per subunit. The JAMM motif is vital for the protease activity. STAMBPL1 is a member of the peptidase M67C family. STAMBPL1 contains 1 MPN (JAB/Mov34) domain.

Dickkopf-related protein 3 (DKK3) belongs to the DKK protein family including Dkk-1, 2, 3 and -4. DKK3 is a 350 amino acid secreted glycoprotein which is comprised of an N-terminal signal peptide and 2 conserved cysteine-rich domains that are separated by a 12 amino acid linker region. DKK3 is involved in embryonic development through its inhibition of the WNT signaling pathway. DKK3 gene expression is decreased in a variety of cancer cell lines and it may act as a tumor suppressor gene.

40S ribosomal protein S13 (RPS13), is a member of the ribosomal protein S15P family. Ribosomes are the organelles which catalyze protein synthesis, consist of a small 40S subunit and a large 60S subunit. RPS13 is located in the cytoplasm and contains multiple phosphorylated residues. Similar to other ribosomal proteins, Ribosomal Protein S13 exists as multiple processed pseudogenes which are scattered throughout the genome.

Adiponectin is a protein exclusively secreted from adipose tissue. In the circulation, adiponectin is present as three different oligomeric complexes, including the high molecular weight (HMW), the middle molecular weight (MMW, also called hexamer) and low molecular weigh (LMW, also called trimer) forms. Different oligomeric complex of adiponectin activates different signaling pathways and exerts distinct functions.

UCN119B is a member of the PDE6D/unc-119 family. UCN119B has a large number of photoreceptors of the retina. Additionaly, UCN119B has a strong homology with the C. elegans unc119 and is able to functionally complement the C. elegans unc119 mutation gene.

CHMP4A is a member of the SNF7 family and operates as chromatin-modifying protein. CHMP4A is a key component of the endosomal sorting vital for transport complex III (ESCRT-III) which takes part in multivesicular bodies (MVBs) formation and sorting of endosomal cargo proteins into MVBs. Additionally, during HIV-1 infection, the virus utilizes the ESCRT-III complex to facilitate budding and exocytosis of viral proteins through the connection of CHMP4 and a protein engaged by HIV-1 p6, which exists in viral Gag assembly and budding. CHMP4A is expressed in higher quantities in skeletal muscle, kidney, liver and heart.

TARDBP binds both DNA and RNA and have numerous roles in transcriptional repression, pre-mRNA splicing and translational regulation. TARDBP was initially identified as a transcriptional repressor that binds to chromosomally integrated TAR DNA and represses HIV-1 transcription. TARDBP has also been identified in individuals diagnosed with chronic traumatic ncephalopathy, a condition which frequently mimics ALS and that has been associated with athletes who have experienced multiple concussions and other types of head injury. TARDBP may also be involved in microRNA biogenesis, apoptosis and cell division.

Frizzled-Related Protein (FRZB) is a secreted protein which is involved in the regulation of bone development. FRZB gene defects cause the female-specific osteoarthritis (OA) susceptibility. sFRPS (Soluble frizzled-related proteins) serve as modulators of Wnt signaling by way of direct interaction with Wnts. sFRPS have a role in regulating cell growth and differentiation in specific cell types. SFRP3/FRZB is involved in limb skeletogenesis. FRZB regulates chondrocyte maturation and long bone development.

SNURF is an extremely basic protein restricted to the nucleus. The evolutionarily reserved open reading frame is located on a bicistronic transcript which has a downstream ORF encoding the small nuclear ribonucleoprotein polypeptide N. The first three exons of the transcript are exploited by the upstream coding region which is known as an imprinting center. The full-length nature of these transcripts is yet to be determined but multiple transcription initiation sites have been identified and large scale alternative splicing takes place in the 5' untranslated region. An alternate exon which substitutes for exon 4 and leads to a truncated, monocistronic transcript was identified. Deletion or alternative splicing produced by a translocation event in the 5' UTR or coding region of this gene results in Prader-Willi syndrome or Angelman syndrome because of parental imprint switch failure.

Stratifin is part of the 14-3-3 family. The 14-3-3 family of proteins plays an important regulatory function in signal transduction, checkpoint control, apoptotic and nutrient-sensing pathways. 14-3-3 proteins are highly conserved and ubiquitously expressed. There are 7 isoforms, beta, gamma, epsilon, sigma, zeta, tau and eta that have been identified in mammals. Stratifin is an epithelial cell marker that functions as a tumor suppressor whose expression can be down regulated via methylation. Failure of Stratifin expression results in a defective G2/M phase checkpoint and results in epithelial and non-epithelial tumorigenesis.

JmjC domain-containing protein 7 (JMJD7) is a member of the JMJD family. JMJD7 encodes highly conserved proteins with a JmjC domain, which are part of the cupin metalloenzyme superfamily. JMJD7 was first thought to be an alternatively spliced isoform of PLA2G4B. It is derived from JMJD7 which is located upstream of PLA2G4B. Most tissues also express read-through transcripts from JMJD7 into the downstream PLA2G4B gene, some of which may encode fusion proteins combining the N-terminus of JMJD7 with PLA2G4B protein.

BNIP1 belongs to the of the BCL2/adenovirus E1B 19 kd-interacting protein (BNIP) family. BNIP1 interacts with the E1B 19 kDa protein, which defends cells from virally-induced cell death. In addition, BNIP1 interacts with E1B 19 kDa-like sequences of BCL2 which is an additional apoptotic protector. Adding up, BNIP1 is implicated in vesicle transport into the endoplasmic reticulum. Alternative splicing results of BNIP1 in four protein products with identical N- and C-termini have been found.

Omentin is a recently recognized gene highly localized to the mental tissue (visceral adipose tissue). Omentin is present in the stromal vascular cells in the adipose tissue rather than in the adipocytes. Omentin is predominantly expressed in the visceral adipose tissue than the subcutaneous tissue, with the omentin mRNA being 150 times higher in the visceral adipose tissue. Omentin has also been detected in human blood using western blot analysis, and seems to increase insulin-stimulated glucose uptake in 3T3-L1 adipocytes in mice. Omentin seems to increase Akt phosphorylation irrespective of insulin presence. Its role in glucose metabolism and obesity remains to be described; an insulin-sensitizing action is possible.Differences in Omentin expression has been noted in adipose tissue from normals and patients with inflammatory bowel disease although its significance is unknown.

Toll interacting protein (TOLLIP) is an inhibitory adaptor protein within Toll-like receptors. The TLR pathway is a part of the innate immune system which recognizes structurally conserved molecular patterns of microbial pathogens, initiating an inflammatory immune response. Negative regulation of TLR signaling by TOLLIP might restrict the production of proinflammatory mediators during inflammation and infection. Furthermore, TOLLIP forms a complex with Tom1 to regulate endosomal transferring of ubiquitinated proteins.

Serpin Peptidase Inhibitor, Clade B Member 8 (SERPINB8) belongs to the ov-serpin subfamily, which, compared with the archetypal serpin PI1, is characterized by a high degree of homology to chicken ovalbumin, absence of N- and C-terminal extensions, lack of a signal peptide, and a serine instead of an asparagine residue at the penultimate position. The superfamily of high molecular weight serine proteinase inhibitors (serpins) control various intracellular and extracellular processes such as complement activation, fibrinolysis, coagulation, cellular differentiation, tumor suppression, apoptosis, and cell migration.

HSPB8 is part of the superfamily of small heat-shock proteins containing a conservative alpha-crystallin domain at the C-terminal part of the molecule. HSPB8 is induced by estrogen in estrogen receptor-positive breast cancer cells. HSPB8 protein functions as a chaperone in association with BAG3, a stimulator of macroautophagy. HSPB8 participates in the regulation of cell proliferation, apoptosis, and carcinogenesis. Mutations in HSPB8 gene have been related with different neuromuscular diseases, including Charcot-Marie-Tooth disease.

Ganglioside GM2 activator (GM2A) is a small glycolipid transport protein which functions as a substrate specific co-factor for the lysosomal enzyme beta-hexosaminidase A. GM2A participates in lipid metabolism. GM2A protein is localized in lysosomes. The GM2A protein forms a large binding pocket for a number of single chain phospholipids and fatty acids. GM2A demonstrates calcium-independent phospholipase activity. GM2A stimulates ganglioside GM2 degradation by presenting GM2 to beta-hexosaminidase A. The Beta-hexosaminidase A, along with GM2A, catalyzes the degradation of the ganglioside GM2, and other molecules containing terminal N-acetyl hexosamines. GM2A gene mutations result in GM2-gangliosidosis type AB or the AB variant of Tay-Sachs disease.