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Streptavidin is a tetrameric protein secreted by Streptomyces avidinii which binds firmly to biotin. Streptavidin is widely used in molecular biology through its unique high affinity for the vitamin biotin. The dissociation constant (Kd) of the biotin-streptavidin complex is about ~10-15 mol/L. The strong affinity recognition of biotin and biotinylated molecules has made streptavidin one of the most important components in diagnostics and laboratory kits. The streptavidin/biotin system has one of the biggest free energies of association of yet observed for noncovalent binding of a protein and small ligand in aqueous solution (K_assoc = 10**14). The complexes are also extremely stable over a wide range of temperature and pH.

CCS is vital for the integration of copper into SOD-1, and as a result is needed for its enzymatic activity. CCS inhibits copper ions from binding to intracellular copper scavengers and provides the SOD-1 enzyme with the required copper cofactor. CCS escorts copper just to SOD-1 and is unable to deliver copper to proteins in the mitochondria, nucleus or secretory pathway. Although many tissues express CCS, the chaperone is most abundant in the kidney, liver and Purkinje cells in the neuropil of the central nervous system.

CNN1 is a member of the calponin family. CNN1 is a thin filament-associated protein which is involved in the regulation and modulation of smooth muscle contraction. CNN1 is able to bind to actin, calmodulin, troponin C and tropomyosin. Prevention of actomyosin Mg-ATPase activity is a result of interaction between calponin and actin.

Penta-EF-hand domain containing 1 (PEF1) is a member of the penta-EF-hand protein family, which shares similarities to the apoptosis linked gene ALG-2. PEF1 forms heterodimers with PDCD6/ALG2 and dissociates from PDCD6/ALG2 in the presence of Ca (2+). Furthermore, PEF1 proteins bind calcium and participate in a various calcium-dependent processes in vertebrates.

PPP1CA is one of the 3 catalytic subunits of protein phosphatase 1 (PP1). PP1 is a serine/threonine specific protein phosphatase which is involved in the regulation of a variety of cellular processes, such as cell division, glycogen metabolism, muscle contractility, protein synthesis, and HIV-1 viral transcription. Increased PP1 activity is detected in the end stage of heart failure. Studies in both human and mice suggest that PP1 is a significant regulator of cardiac function. Mouse studies also propose that PP1 functions as a suppressor of learning and memory.

40S ribosomal protein S5 (RPS5) is a ribosomal protein, which is a member of the ribosomal protein S7P family.Ribosomes, which are the organelles that catalyze protein synthesis, composed of a small subunit and a large subunit that comprise of over 80 distinct ribosomal proteins. RPS5 is a 204 amino acid component of the 40S complex. RPS5 proteins exist as multiple processed pseudogenes which are scattered throughout the genome. RPS5 is expressed at varying amounts in colorectal cancer cells, proposing a possible role in carconigenesis.

The GAGA factor is a sequence-specific DNA-binding protein, which participates in the regulation of the expression of a variety of different classes of genes in Drosophila such as many developmentally regulated genes, stress induced genes, and cell cycle regulated genes, as well as housekeeping genes. GAGA contains a C-terminal glutamine-rich domain and a highly conserved N-terminal POZ domain which reported to be involved in self-oligomerization in a number of other POZ domain containing proteins. In case of GAGA protein, the N-terminal POZ domain mediates the formation of oligomers both in vitro and in vivo.

Transferrin is the iron-transport protein of vertebrate serum and donates iron to cells through interaction with a specific membrane receptor, CD71. Transferrin appears to be indispensable for most cells growing in tissue culture.
It is referred to frequently as a growth factor because, in analogy to other growth factor-receptor interactions, proliferating cells express high numbers of transferrin receptors, and the binding of transferrin to their receptors is needed for cells to initiate and maintain their DNA synthesis. Apart from its role as an iron transport protein transferrin acts as a cytokine and has functions that may not be related to its iron-carrying capacity.
Bovine Transferrin is a crucial component for the cultivation of mammalian cells in- vitro. Bovine Transferrin is Critical for long-term cells growth in-vitro. Bovine Transferrin is used as detoxificant in media by binding contaminating metal ions. Bovine Transferrin is often used as a nutrient in fermentation media for recombinant protein and biopharmaceutical production. Additional common uses of Bovine Transferrin are Molecular weight, Affinity purification of anti-human transferrin antibodies and also as receptor mediated transfection of molecules such as DNA, into cells.

NUDT16 is nuclear nucleoside diphosphatase proteins restricted in foci in the nucleolus and nucleoplasm. NUDT16 is a RNA-decapping enzyme. It binds specifically to U8 snoRNA and can remove m7G and m227G caps from RNAs, rendering them substrates for 5’-3’ exonucleases for degradation in vivo.

C1q is the first component of the classical pathway of complement activation. C1q along with the enzymatically active components C1r and C1s forms the C1 complex. When C1 binds to immunoglobulins in the form of immune complexes, it leads to activation of C1r and C1s proteases and a further activates the classical pathway of complement. C1q is a glycoprotein that belongs to the collectin family, having a molecular weight of about 410-462 kDa. C1q is a hexamer composed of globular heads attached to collagen-like triple-helix tails. The globular heads of C1q exclusively bind to the CH2 domain of IgG molecules or the CH3 domain of IgM. Each heavy chain of the immunoglobulin molecule contains a single binding site for C1q. Given that C1q must bind to no less than two heavy chains in order to alter its conformation and activate C1r and C1s, its activation follows only after binding to immunoglobulins in the form of immune complexes bound to multivalent antigens. C1q’s main physiological role is in the clearance of immune complexes and apoptotic bodies from the organism. Interruption of this process may lead to development of autoimmunity. Individuals with genetic deficiencies of C1q or other components of the classical pathway are at risk to develop SLE. C1q specifically binds to apoptotic bodies of human keratinocytes, vascular endothelial cells and lymphocytes. Complement components C1q and bound C3 mediate the clearance of apoptotic bodies. Hence, C1q may advance the clearance of autoantigens, avoiding stimulation of the immune system. Nonetheless, an extended exposition of the immune system to the neoepitope exposed on C1q molecules bound to immune complexes or apoptotic bodies could ultimately lead to an autoimmune response against C1q itself and to an altered complement function. C1q deficiency may also lead to disruption of the negative selection of autoreactive B cells. C1q along with other specific recognition proteins bind to the highly conserved lupus antigens (dsDNA and nuclear proteins) and activate the complement system. Autoantibodies against C1q (anti-C1q) are found in a number of autoimmune and infectious diseases like glomerulonephritis (GN) and lupus erythematosus (SLE), these antibodies are significant in clinical practice due to their negative predictive value.

Proteasome 26S Subunit, Non-ATPase 5, also known as PSMD5 is a member of the proteasome subunit S5B/HSM3 family. The 26S proteasome is an enzymatic complex which degrades ubiquitinated proteins in eukaryotic cells. Furthermore, PSMD5 acts as a chaperones which is involved in the assembly of the 26s proteasome, particularly of the base subcomplex of the PA700/19S regulatory complex. PSMD5 is full of dileucine repeats, which have been involved in trafficking of various transmembrane proteins.

The 14-3-3 family of proteins plays a key regulatory role in signal transduction, checkpoint control, apoptotic and nutrient-sensing pathways. 14-3-3 proteins are highly conserved and ubiquitously expressed. There are at least seven isoforms, β, γ, ε, σ, ζ, τ and η that have been identified in mammals. The 14-3-3 epsilon, a subtype of the 14-3-3 family of proteins, was thought to be brain and neuron-specific. It has been shown to interact with CDC25 phosphatases, RAF1 and IRS1 proteins, suggesting its role in diverse biochemical activities related to signal transduction, such as cell division and regulation of sensitivity. It has also been implicated in the pathogenesis of small cell lung cancer.

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.

mRNA turnover protein 4 homolog (MRTO4) is a member of the ribosomal protein L10P family. MRTO4 is a protein sharing a low level of sequence similarity with ribosomal protein P0. Though the precise function of the MRTO4 is presently unknown, it seems to be involved in mRNA turnover and ribosome assembly. MRTO4 is a nucleolar component of the ribosome assembly apparatus which shares remarkable similarity and contends for binding to the 25S rRNA GAR domain with the ribosomal protein P0. The MRTO4 gene is located on human chromosome 1, which extends over 260 million base pairs, is comprised of over 3,000 genes and contains approximately 8% of the human genome.

TYRO3 Protein Tyrosine Kinase or TYRO3 is a transmembrane receptor tyrosine kinase. TYRO3 has crucial role in essential processes such as cell migration, actin reorganization and cell survival. It is activated and signaled by MAPK/ERK and PI3K/AKT that expedites the cellular functions of protein.

BIRC7 is a part of the inhibitor of apoptosis protein (IAP) family and contains a single copy of a baculovirus IAP repeat (BIR) as well as a RING-type zinc finger domain. The BIR domain is necessary for inhibitory activity & cooperates with caspases, while the RING finger domain sometimes increases anti-apoptotic activity but doesn’t inhibit apoptosis by itself. 2 transcript variants encoding diverse isoforms have been found for this gene. The 2 isoforms have dissimilar antiapoptotic characteristics, with isoform a protecting cells from apoptosis induced by staurosporine and isoform b defending cells from apoptosis induced by etoposide.
BIRC7 has direct contact with several caspases together with caspase-3, caspase-7, & caspase –9. BIRC7 inhibits the activation of caspase-9 induced by Apaf-1, cytochrome c, and dATP.

Endothelin-2 is a Hypoxia-induced Autocrine Survival Factor for Breast Tumor Cells. The synthesis of EDN2 by human kidney carcinoma cells is decreased by EGF. EDN2 is a chemoattractant for macrophages and THP-1 monocytic cells. Chemotaxis towards EDN2 is via the MAPK pathway: p44 and p42 are phosphorylated when THP-1 cells are stimulated with EDN2. Migration to EDN2 is inhibited by hypoxia and by pertussis toxin. EDN2 leads to activation of macrophages. EDN2 shares a similar peptide sequence with chemokines and may signal via a similar receptor and MAPK-mediated pathway. Furthermore, EDN2 expression by tumors may modulate the behavior of macrophages such that activated cells accumulate in areas of hypoxia.

MBP is a major component of the myelin sheath of oligodendrocytes and Schwann cells in the nervous system, although, MBP-related transcripts are also present in the bone marrow and the immune system. These mRNAs emerge from the long MBP gene which holds three additional exons located upstream of the classic MBP exons. The Golli mRNAs contain three exons unique to Golli-MBP, spliced in-frame to one or more MBP exons. The second family of transcripts contains only MBP exons and produces the well characterized myelin basic proteins. MBP transcription unit is an essential part of the Golli transcription unit and the arrangement is important for the function and/or regulation of these genes.

Charged multivesicular body protein 1b (CHMP1B) is a member of the chromatin-modifying protein/charged multivesicular body protein (CHMP) family. CHMP1B is a possible peripherally associated component of the ESCRT-III (endosomal sorting required for transport complex III) which is involved in MVBs (multivesicular bodies) formation and sorting of endosomal cargo proteins into MVBs. The MVBs contain ILVs (intraluminal vesicles) which are created by invagination and scission from the limiting membrane of the endosome and generally are transported to lysosomes enabling degradation of membrane proteins, such as stimulated growth factor receptors, lysosomal enzymes and lipids.

Peroxisome proliferators are non-genotoxic carcinogens which are purported to exert their effect on cells through their interaction with members of the nuclear hormone receptor family termed peroxisome proliferators activated receptors (PPARs). Nuclear hormone receptors are ligand-dependent intracellular proteins that stimulate transcription of specific genes by binding to specific DNA sequences following activation by the appropriate ligand. Studies indicate that PPARs are activated by peroxisome proliferators such as clofibric acid, nafenopin, and WY-14,643, as well as by some fatty acids.

Acetoacetyl-CoA thiolase (ACAT1) is an enzyme member of the membrane-bound acyltransferase family and Sterol o-acyltransferase subfamily. The ACAT1 enzyme catalyzes the reversible formation of acetoacetyl-CoA from 2 molecules of acetyl-CoA. ACAT1 plays a part in lipoprotein compilation and dietary cholesterol absorption. Added to its acyltransferase activity, ACAT1 acts as a ligase.

YY1 Transcription Factor, also known as YY1, is a part of the GLI-Kruppel class of zinc finger proteins. YY1 has a positive and negative effect on a various cellular and viral genes by binding to sites overlapping the transcription start site. YY1 leads histone deacetylases and histone acetyltransferases to a promoter in order to activate or repress the promoter.

Collapsin response mediator proteins (CRMPs) are cytosolic phosphoproteins involved in neuronal differentiation and axonal guidance. CRMP2 was previously shown to mediate the repulsive effect of Sema3A on axons and to participate in axonal specification. The X-ray crystal structure of murine CRMP1 was determined at 2.1 resolution and demonstrates that CRMP1 is a bilobed ‘lung-shaped’ protein forming a tetrameric assembly.

TREM1 is a transmembrane receptor protein that is involved in monocytic activation and in the inflammatory response. TREM1 is expressed on the surface of neutrophils, mature monocytes and macrophages. TREM1 stimulates neutrophil and monocyte-mediated inflammatory responses. TREM1 also triggers the release of pro-inflammatory chemokines and cytokines, as well as increased surface expression of cell activation markers. Furthermore, TREM1 is an amplifier of inflammatory responses that are triggered by bacterial and fungal infections and is a fundamental mediator of septic shock. The expression of the soluble form of TREM1 increases during sepsis and can consequently be used as a biological marker for septic shock. TREM1 is strongly expressed in acute inflammatory lesions caused by bacteria and fungi. Increased TREM1 expression on monocytes is related to both infectious and noninfectious inflammatory processes.
TREM1 is vastly expressed in adult liver, lung and spleen than in corresponding fetal tissue. TREM1 is also expressed in the lymph node, placenta, spinal cord and heart tissues. TREM1 expression is more elevated in peripheral blood leukocytes than in the bone marrow and in normal cells than malignant cells. TREM1 is expressed at low levels in the early development of the hematopoietic system and in the promonocytic stage and at high levels in mature monocytes.