Supplier: AbFrontier

The complement system is a crucial component of the innate immunity against microbial infection. Complement factor H, a 155 kDaplasma glycoprotein, is an essential regulatory protein that plays a critical role in the homeostasis of the complement system in plasma and in the protection of bystander host cells and tissues from damage by complement activation. Factor H binds to C3b, accelerates the decay of the alternative pathway C3-convertase and acts as a cofactor for the factor I-mediated proteolyticinactivation of C3b. In addition, factor H has multiple physiological activities 1) acts as an extracellularmatrix component, 2) binds to cellular receptors of the integrintype, and 3) interacts with a wide selection of ligands, such as the C-reactive protein, thrombospondin, bone sialoprotein, osteopontin, and heparin. Complement factor H has revealed an association with two different renal diseases, glomerulonephritisand atypical hemolytic uremicsyndrome (aHUS).

Supplier: AbFrontier

Human serum albumin (HSA) is the most abundant protein in mammalian plasma and is generally considered to be a multifunctional transport protein. HSA is a signle-chain protein synthesized in and secreted from liver cells. HSA has significant antioxidant activity and may represent the major and predominant circulating antioxidant in plasma, which is known to be exposed to continuous oxidative stress. HSA protects human low density lipoproteins against copper-mediated oxidation and blood against hemolysis by free radicals. HSA which are exposed to glucose and have a relatively slow turnover rate are particularly susceptible to nonenzymatic glycosylation. Structural changes in glycosylated albumin lead to a reduction in affinity for fatty acid.

Supplier: AbFrontier

Fibronectin (FN) exists in two main forms: 1) as a soluble glycoprotein in blood plasma (plasma FN), and 2) as an insoluble glycoprotein in tissue extracellular matrices (cellular FN). Many different cell types synthesize fibronectin and secrete it as a disulfide-bonded dimer composed of 230–270 kDa subunits. FN is one of the largest multi-domain proteins that interact with a variety of macromolecules like heparin, collagen /gelatin, and fibrin. FN is involved in many cellular processes, including tissue repair, embryogenesis, blood clotting, and cell migration/ adhesion and so can be used as a therapeutic agent for wound healing. In addition, its age-dependent increase in plasma and tissues may be accompanied in pathological states, especially in tumor growth, by its proteolytic breakdown.

Supplier: AbFrontier

Attractin is a serum glycoprotein of 175 kDa and found in both membrane-bound and secreted forms as a result of alternative splicing. Both the secreted and membrane-bound forms of attractin may be involved in the development and maintenance of the central nervous system. Membrane-bound attractin is a co-receptor for Agouti, antagonist of melanocortin-1 receptor. Secreted attractin, expressed by activated T lymphocytes and modulates interactions between T cells and monocytes/macrophages, was examined as a potential marker of immune activity. Attractin may be a component of a pathway for regulated protein turnover that also involves mahogunin, a wide-expressed E3 ubiquitin ligase found at particularly high levels in the brain. Attractin was considered as an extracellular target amenable for the development of obesity-regulating drugs, also.

Supplier: AbFrontier

Selenoprotein-P(SelP) is the major selenoprotein in human blood plasma and a transport protein which is carrying selenium to various extrahepatic tissues. Though its expression is detected in most tissues, highest amounts are produced by the liver, which secretes highly glycosylated SelP into plasma. Purification of human SelP yields two distinct isoforms with 61 and 55 kDa, differing in selenium content. SelP also has been shown to chelate heavy metals such as cadmium and mercury, and there are several evidences about its serum antioxidant capacity and protection against oxidative stress. Selenium deficiency predispose to several pathological condition such as cancer, coronary heart disease and liver necrosis although the biological function of SelP in various pathologic conditions has not been established.

Supplier: AbFrontier

NF-κB (Nuclear Factor kappa B) is a nuclear transcription factor found in all cell types and is involved in cellular responses to stimuli such as stress, cytokines, free radicals, ultraviolet irradiation, and bacterial or viral antigens. NF-κB plays a key role in regulating the immune response to infection. Consistent with this role, incorrect regulation of NF-κB has been linked to cancer, inflammatory and autoimmune diseases, septic shock, viral infection and improper immune development. There are five members in the NF-κB family: NF-κB1, NF-κB2, RelA (also named p65), RelB, and c-Rel. The RelB protein is present in the cytosol, bound to p50 or p52 and an inhibitory IκB protein, forming an inactive trimeric complex. Following cell signalling events leading to IκB degradation, Rel/NFκ-B proteins are translocated to the nucleus where they regulate gene expression. The genes controlled by Rel/NF-κB family members are predominantly genes involved in the host response to infection, stress and injury. RelB mediates the regulation of genes involved in immune and inflammatory processes.

Supplier: AbFrontier

Enolase (2-phosphogly-cerate hydrolyase or phosphopyruvate hydrates) is a glycolytic enzyme that catalyzes the dehydration and conversion of 2-phosphoglycerate to phosphoenolpyruvate. It comprises three distinct subunits, alpha, beta and gamma. Non Neuronal Enolase(ENO1) is an isoform of mammalian enolase and is composed of 2 alpha subunits. The gene for ENO1 also encodes a shorter monomeric structural lens protein, tau-crystallin.
Multifunctional enzyme that, as well as its role in glycolysis, plays a part in various processes such as growth control, hypoxia tolerance and allergic responses. May also function in the intravascular and pericellular fibrinolytic system due to its ability to serve as a receptor and activator of plasminogen on the cell surface of several cell-types such as leukocytes and neurons. Stimulates immunoglobulin production.
Used as a diagnostic marker for many tumors and, in the heterodimeric form, alpha/gamma, as a marker for hypoxic brain injury after cardiac arrest. Also marker for endometriosis. Antibodies against alpha-enolase are present in sera from patients with cancer-associated retinopathy syndrome (CAR), a progressive blinding disease which occurs in the presence of systemic tumor growth, primarily small-cell carcinoma of the lung and other malignancies. Is identified as an autoantigen in Hashimoto encephalopathy (HE) a rare autoimmune disease associated with Hashimoto thyroiditis (HT). HT is a disorder in which destructive processes overcome the potential capacity of thyroid replacement leading to hypothyroidism

Supplier: AbFrontier

Reversible phosphorylation of tyrosine residues is a key regulatory mechanism for numerous cellular events such as proliferation, differentiation, gene expression and migration. Abnormalities in tyrosine phosphorylation play a role in the pathogenesis of numerous inherited or acquired human diseases from cancer to immune deficiencies.
There are at least 107 genes coding for PTPs (protein tyrosine phosphatases) in the human genome.
All known PTPs contain a highly conserved 12 amino acid catalytic
domain and are further distinguished on the basis of additional structural motifs. The receptor-like PTPs exhibit an extracellular domain, a single transmembrane and one or two intracellular phosphatase domains. The nonreceptor cytoplasmic PTPs contain a single phosphatase domain and additional amino acid sequences that are homologous to motifs found in other classes of proteins.
Protein tyrosine phosphatases PTPN5 (STEP), PTPRR and PTPN7 comprise a family of phosphatases that specifically inactivate MAPKs (mitogen-activated protein kinases).
There are multiple forms of STEP in the adult rat brain which show differential enrichment in brain regions implicated in aspects of cognitive,
affective, and motor behaviors. Some of the STEP isoforms are generated through alternative splicing of a single STEP gene and each has unique intracellular targets and functions.

Supplier: AbFrontier

The two ubiquitin C-terminal hydrolase(UCH) enzymes, UCHL1 and UCHL3, deubiquitinate ubiquitin-protein conjugates and control the cellular balance of ubiquitin. UCHL1 and UCHL3 are both small proteins of ~220 amino acids that share more than 40% amino acid sequence identity.
UCHL3 is universally expressed in all tissues, while UCHL1 is expressed exclusively in neuronal tissue, testis and ovary. The activity of UCHL3 is more than 200 fold higher than UCHL1 when a fluorogenic ubiquitin substrate is used. UCHL1 associates with monoubiquitin and UCHL3 binds to Nedd8, ubiquitin-like protein. UCHL1 and UCHL3 play a role in the regulation of neuronal development and spermatogenesis. UCHL1 is involved in the pathogenesis of Parkinson’s disease(PD) and Alzheimer’s disease (AD). Down-regulation and extensive oxidative modification of UCHL1 have been observed in the brains of AD patients as well as PD patients.

Supplier: AbFrontier

Amphiphysins, members of the BAR (Bin-Amphiphysin-Rvsp) protein super family, play a key role in clathrin-mediated endocytosis of synaptic vesicles (SVs). All members of the BAR family share a highly conserved N-terminal BAR domain and a C-terminal Src homology (SH3) domain. Two isoforms of amphiphysin have been identified and act in concert as a heterodimer. Amphiphysins interact via its carboxy-terminal SH3 domain with dynamin, synaptojanin and clathrin. These complexes are implicated in synaptic vesicle recycling at nerve terminal.  Amphiphysins were also identified as the dominant autoantigen in paraneoplastic Stiff-Man Syndrome.

Supplier: AbFrontier

Anti-mRNA capping enzyme Mouse Monoclonal Antibody [clone: T16-AF3F1]

Supplier: AbFrontier

IA-2 (insulinoma-associated protein 2, ICA512, PTPRN) is a member of the transmembrane protein tyrosine phosphatase (PTP) family located in secretory granules of neuroendocrine cells. The IA-2 protein is 979 amino acids in length and consists of a luminal domain, transmembrane domain, and cytoplasmic domain. Although a member of the PTP family, IA-2 lacks phosphatase activity with known substrates due to amino acid substitutions at critical sites in its PTP domain. Two paralog RPTPs, IA-2 and IA-2β were identified as major autoantigens in type-1 diabetes mellitus. On granule exocytosis, the IA-2 cytoplasmic domain is cleaved and the resulting cytosolic fragment moves into the nucleus where it enhances the levels of phosphorylated STAT5 and STAT3, thereby inducing insulin gene transcription and granule biogenesis. IA-2 signaling enhances pancreatic β–cell proliferation by regulating cyclins D through STATs.

Supplier: AbFrontier

Vimentin is a member of the intermediate filament family of proteins found in various non-epithelial cells, especially mesenchymal cells. Vimentin is responsible for maintaining cell shape, integrity of the cytoplasm, and stabilizing cytoskeletal interactions. Vimentin plays a significant role in supporting and anchoring the position of the organelles in the cytosol. Although most intermediate filaments are stable structures, vimentin also has a dynamic nature which is important when offering flexibility to the cell.
Two monomers which have central α-helical domains, capped on each end by non-helical domains twist around each other to form a coiled-coil dimer. Two dimers then form a tetramer, which, in turn, form a sheet by interacting with other tetramers.
There are some reports related to the biochemical function of intermediate filament network. The intracellular movement of LDL-derived cholesterol from the lysosome to the site of esterification is a vimentin-dependent process. A role for vimentin in mechanotransduction of shear stress has also been suggested. The mechanical stress of fluid shear on endothelial cells seems to trigger MAPK signaling pathways and stimulates proliferation.

Supplier: AbFrontier

The RIP(receptor-interacting protein) family of serine/Threonine kinases(RIP-1,2,3,4,5,6,7) are crucial regulators of cell survival and cell death that can trigger pro-survival, inflammatory and immune responses via the activation of transcription factors(NF-kB and AP-1) and death-inducing programs.
RIP2(also known as RICK, CARDIAK, CCK and Ripk2) transduces signals from receptors of both immune responses. RIP2 carries a CARD at its C-terminal, which is essential for NF-kB activation. RIP2 is a critical downstream mediator of Nod1 and Nod2 signaling. Overexpression of RIP2 results in the activation of, in addition to NF-kB, the MAPKs JNK and ERK2, requiring its kinase activity to activate ERK2, but not JNK.

Supplier: AbFrontier

Focal adhesion kinase subfamily consists of the non-receptor proline-rich protein tyrosine kinases (PTKs). Two members of the family are focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (PYK2). These two kinases have molecular mass between 110-125 kDa and are closely related in their structure. The presence of two proline-rich motifs within the C-terminal domains is conserved.
FAK is a nonreceptor and nonmembrane associated PTK which does not contain Src homology 2 (SH2) or SH3 protein interaction domains. The centrally located kinase domain of FAK is flanked by large N- and C-terminal noncatalytic domains.
FAK links integrin receptors to intracellular signaling pathways that are important for cell growth, survival, and migration. Integrin receptor engagement with ligands such as fibronectin can stimulate FAK autophosphorylation which enables FAK to function within a network of integrin-stimulated signaling pathways leading to the activation of targets such as the ERK and JNK/mitogen-activated protein kinase pathways. Recent study reveals that FAK is essential for angiogenesis in the embryo, functions in heart development and modulates the response of cardiomyocytes to pressure overload in adult mice.

Supplier: AbFrontier

Heat shock proteins are ubiquitous proteins and have been characterized as cytoprotective molecular chaperones. The typical function of a chaperone is to assist a protein to attain its functional conformation to prevent non-functional aggregation of misfolded proteins. The principal HSP families are HSP90, HSP70, HSP60 and the small HSPs including HSP27, ubiquitin, α-crystallin, Hsp20 and others. The common functions of small Hsps are chaperone activity, thermotolerance, inhibition of apoptosis, regulation of cell development, and cell differentiation.
Hsp27 has a molecular weight of approximately 27 kDa, although it has been shown to form large aggregates of up to 800 kDa in the cytosol. Hsp27 is found in several types of human cells, including tumour cells. Hsp27 interferes with apoptosis through its ability to interact with and inhibit key components of the apoptotic signaling pathway, including the caspase activation complex. Overexpression of heat shock proteins can increase the tumorigenic potential of tumour cells. HSP27 also has been reported to be involved in development and progression of hormone-refractory prostate cancer.

Supplier: AbFrontier

Synuclein is a small, soluble protein primarily expressed in neural tissue. The synuclein family includes three known proteins: α-synuclein, β-synuclein, and γ-synuclein.
α-Synuclein is a very conserved, small acidic protein (140 residues) with a molecular weight of approximately 19 kDa that accounts for about 1% of total protein in neurons. It is concentrated primarily in presynaptic axon terminals and plays a central role in initiating Parkinson’s disease. It is the principal constituent of Lewy bodies which are formed by protein aggregation and inclusion body formation.
α-Synuclein lacks secondary or tertiary structure, so it belongs to the family of natively unfolded proteins, many of which act as chaperones. Much of this α-synuclein has been post-translationally modified to increase the rate of oligomerization.
Mutant forms of α-Synuclein are associated with autosomal dominant Parkinson’s disease. The mutations increase the aggregation rate of the resultant α-synuclein
β-Synuclein is found primarily in brain tissue and is seen mainly in presynaptic terminals. It is predominantly expressed in the neocortex, hippocampus, striatum, thalamus, and cerebellum.
β-Synuclein may protect the central nervous system from the neurotoxic effects of α-synuclein by inhibiting aggregation of α-synuclein which occurs in neurodegenerative diseases such as Parkinson's disease.
γ-Synuclein is a synuclein protein found primarily in the peripheral nervous system (in primary sensory neurons, sympathetic neurons, and motor neurons) and retina. γ-Synuclein expression in breast tumors is a marker for tumor progression.

Supplier: AbFrontier

Plasmid vectors for the expression of coding regions of eukaryotic genes in bacterial, insect and mammalian hosts are in common usage. The expression vectors are used to encode hybrid fusion proteins consisting of a eukaryotic target protein and a specialized region designed to aid in the
purification and visualization of the target protein. Short pieces of welldefined peptides(Poly-His, Flag-epitope or cmyc epitope or HA-tag) or small proteins (bacterial GST, MBP) is often cloned along with the target gene. The HA tag is derived from an epitope of the influenza hemagglutinin protein, which has been extensively used as a general epitope tag in expression vectors. It has been successfully used in a
variety of applications, including Western blotting, Immunoprecipitation, and immunofluorescence studies.

Supplier: AbFrontier

ERK1 and ERK2 are widely expressed and are involved in the regulation of meiosis, mitosis, and postmitotic functions in differentiated cells.
Many different stimuli, including growth factors, cytokines, virus infection, ligands for heterotrimeric guanine nucleotidebinding protein (G protein)-coupled receptors and transforming agents, activate the ERK1 and ERK2 pathways. When growth factors bind to the receptor tyrosine kinase, Ras interacts with Raf, the serine/threonine protein kinase and activates it as well. Once actived, Raf phosphorylates serine residue in 2 further kinases, MEK1/2, which in turn phosphorylates tyrosine/threonine in extracellular-signal regulated kinase(ERK) 1/2. Upon activation, the ERKs either phosphorylate a number of cytoplasmic targets or migrate to the nucleus, where they phosphorylate and activate a number of transcription factors such as c-Fos and Elk-1.

Supplier: AbFrontier

Cyclin-dependent kinase-5(CDK5) is a member of the cyclin-dependent kinase family of serine/threonine kinases. Its mRNA and protein are expressed in the kidneys, testes, and ovaries. And Its activity has been detected almost exclusively in brain extracts. Similar to other Cdks, monomeric Cdk5 displays no enzymatic activity; however, Cdk5 is not activated by cyclins. Instead, Cdk5 activity requires association with one of two brain-specific regulatory subunits, called p35 and p39. These two activators regulate the spatial and temporal expression of active Cdk5, restricting its activity primarily to post-mitotic neurons.

Supplier: AbFrontier

Vimentin is a member of the intermediate filament family of proteins found in various non-epithelial cells, especially mesenchymal cells. Vimentin is responsible for maintaining cell shape, integrity of the cytoplasm, and stabilizing cytoskeletal interactions. Vimentin plays a significant role in supporting and anchoring the position of the organelles in the cytosol. Although most intermediate filaments are stable structures, vimentin also has a dynamic nature which is important when offering flexibility to the cell.
Two monomers which have central α-helical domains, capped on each end by non-helical domains twist around each other to form a coiled-coil dimer. Two dimers then form a tetramer, which, in turn, form a sheet by interacting with other tetramers.
There are some reports related to the biochemical function of intermediate filament network. The intracellular movement of LDL-derived cholesterol from the lysosome to the site of esterification is a vimentin-dependent process. A role for vimentin in mechanotransduction of shear stress has also been suggested. The mechanical stress of fluid shear on endothelial cells seems to trigger MAPK signaling pathways and stimulates proliferation.

Supplier: AbFrontier

Superoxide dismutase (SOD) is an antioxidant enzyme involved in the defense system against reactive oxygen species (ROS). SOD catalyzes the dismutation reaction of superoxide radical anion (O2-) to hydrogen peroxide, which is then catalyzed to innocuous O2 and H2O by glutathione peroxidase and catalase. Several classes of SOD have been identified. These include intracellular copper, zinc SOD (Cu, Zn-SOD/SOD-1), mitochondrial manganese SOD (Mn-SOD/SOD-2) and extracellular Cu, Zn-SOD (EC-SOD/SOD-3) (1). SOD-1 is found in all eukaryotic species as a homodimeric 32 kDa enzyme containing one each of Cu and Zn ion per subunit (2). The manganese containing 80 kDa tetrameric enzyme SOD2, is located in the mitochondrial matrix in close proximity to a primary endogenous source of superoxide, the mitochondrial respiratory chain (3). SOD-3 is a heparin-binding multimer of disulfide-linked dimers, primarily expressed in human lungs, vessel walls and airways (4). SOD-4 is a copper chaperone for superoxide dismutase (CCS), which specifically delivers Cu to copper/zinc superoxide dismutase. CCS may activate copper/zinc superoxide dismutase through direct insertion of the Cu cofactor.

Supplier: AbFrontier

Cyclins play a key role in the orderly progression of the cell division cycle through their timed expression and their ability to bind, activate and enhance substrate affinity of their associated cyclin-dependent protein kinases (CDKs). E-type cyclins (cyclin E1 and cyclin E2) are expressed during the late G1 phase of the cell cycle until the end of the S-phase. Cyclin E binds and activates the kinase Cdk2 and by phosphorylating its substrates, the cyclic/Cdk2 complexes initiate a cascade of events that leads to the expression of S-phase specific genes. Besides this specific function as a regulator of S-phase-entry, cyclin E plays a direct role in the initiation of DNA replication, the control of genomic stability, and the centrosome cycle.

Supplier: AbFrontier

The inter-α-trypsin inhibitor (ITI, IαI) family, a typical and classical example for protein-glycosaminoglycan-protein (PGP) complexes, occurs constitutively in plasma at relatively high concentrations and is a result of alternate combinations of three kinds of heavy chains with a common light chain, the bikunin proteoglycan. Bikunin has two proteinase inhibitor domains and belongs to the Kunitz-type protease inhibitor family; it displays an inhibitory activity against trypsin, leukocyte elastase and plasmin. The heavy chains do not have any protease inhibitory properties but have the capacity to interact in vitro and in vivo with hyaluronic acid and this binding promotes the stability of the extra-cellular matrix. The ITI protein family is suspected of playing a key role in the extra-cellular matrix biology.

Supplier: AbFrontier

Kininogens are precursors for kinin, and the two main types of them are high-molecular weight kininogen (HMWK) and low-molecular weight kininogen (LMWK). HMWK also known as the Williams-Fitzgerald-Flaujeac factor is a protein from the blood coagulation system as well as the kinin-kallikrein system. It acts mainly as a cofactor on coagulation and inflammation, and has no intrinsic catalytic activity. LMWK is produced locally by numerous tissues, and secreted together with tissue kallikrein.
Kininogens are synthesized in the liver and circulate in the plasma and other body fluids.
The kinins are pharmacologically active polypeptides released in the tissues and body fluids as a result of the enzymatic action of kallikreins on kininogens. The kinin family includes bradykinin (BK) (Arg-Pro-Pro-gly-Phe-Ser-Pro-Phe-Arg), kallidin (Lys-Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg) and methionyl-lysyl-BK (Met-Lys-Arg-Pro-Pro-Gly-Phe-Arg). Kallidin and methionyl-lysyl-BK are converted into BK by aminopeptidases present in plasma and urine. Active tissue kallikrein acts on LMWK to release kallidin. The plasma kallikrein is found in circulation in an inactive form, which is known as prekallikrein or Fletcher factor.
BK and kallidin act through activation of G-protein-coupled constitutive B(2) or inducible kinin B(1) receptors linked to signaling pathways involving increased intracellular Ca concentrations and/or release of mediators including arachidonic acid metabolites, NO and EDHF (Endothelium-derived hyperpolarizing factor). In the cardiovascular system, the kallikrein-kinin system exerts a fine control of vascular smooth muscle tone and arterial blood pressure, and plays a significant cardioprotective effect.

Supplier: AbFrontier

Platelet-derived growth factors (PDGFs) have been implicated in the control of cell proliferation, survival and migration. The PDGF family of growth factors consists of five different disulphide-linked dimers built up of four different polypeptide chains encoded by four different genes. Theses isoforms, PDGF-AA, PDGF-AB, PDGF-BB, PDGF-CC and PDGF-DD, act via two receptor tyrosine kinases, PDGF receptors α and β. Thus far, gene-targeting experiments have been attempted to create knockout mice deficient for PDGFR-α or PDGFR-β. Those mice, however, died either at the embryonic stage or several days after birth. Platelet-derived growth factor receptors, PDGFR-α and PDGFR-β, have five extracellular immunoglobulin-like domains and an intracellular tyrosine kinase domain. Upon binding a PDGF, the receptors form homo- and heterodimers. Dimerization of the receptors juxtaposes the intracellular part of the receptors, which allow phosphorylation in trans between the two receptors in the complex. These autophosphorylation provide docking sites for downstream signal transduction molecules. More than 10 different SH2–domain-containing molecules have been shown to bind to different autophosphorylation sites in the PDGF α- and β-receptors. There are signal transduction molecules with enzymatic activity, such as PI3-kinase, PLC-γ, Src, SHP-2, GAP, as well as adaptor molecules such as Grb2, Shc, Nck, Grb7 and Crk, and Stats. Each of the different partners recruited by the activated receptor initiates different signaling pathways, making possible a great variety of cellular response.

Supplier: AbFrontier

Insulin receptor substrate (IRS) proteins play a central role in maintaining basic cellular functions such as growth and metabolism through insulin/insulin like growth factor (IGF) signaling. Four members (IRS-1, IRS-2, IRS-3, IRS-4) of this family have been identified which differ in their subcellular distribution and interaction with SH2 domain proteins. After phosphorylation by activated receptors, these intracellular signaling molecules recruit various downstream effector pathways including phosphatidylinositol 3-kinase, tyrosine protein phosphatase SHPTP-2, and several smaller adapter molecules such as the growth factor receptor-binding protein Grb-2.
IRS-1, the best characterized IRS protein, has eighteen potential tyrosine phosphorylation sites which directly bind to SH2 domains in downstrem proteins. IRS-1 consists of amino terminal containing pleckstrin homology (PH) domain followed by a phosphotyrosine-binding (PTB) domain which binds to IR and IGFR, and carboxy terminal containing multiple tyrosine and serine residues which become docking sites for proteins that have PTB domain such as SH2 domain.
IRS-4 is the last identified member of the IRS family. Cloning of human IRS-4 revealed a predicted protein of similar length to both IRS-1 and IRS-2and showed only 27% and 29% identity with IRS-1 and IRS-2, respectively. In contrast, IRS-4 exhibits higher degree of homology in the PH domain (43 to 50 %) and the PTB domain (43 to 66%) with the corresponding domains in IRS-1, IRS-2 and IRS-3.
IRSs are also thought to be able to induce malignant transformation. IRS-1 has been shown to be constitutively active in breast cancer.

Supplier: AbFrontier

Methionine sulfoxide reductase (MsrA) reduces methionine sulfoxide (MetO) residues in proteins and free MetO to Methionine (Met). The catalytic activity of MsrA is dependent of bound metal and cofactors but it requires reducing equivalents from either DTT or a thioredoxin-regenerating system. MsrA plays an essential role in protecting cells against oxidative damage. The substrates of MsrA include calmodulin, HIV protease and 1-proteinase-inhibitor (1-3). Recent studies indicate that there is a connection between MsrA and Alzheimer’s disease in mammals (4).

Supplier: AbFrontier

Mitogen- and stress-activated protein kinases (MSK2) is nuclear kinase that act downstream of mitogen-activated protein/extracellular signal-regulated kinase pathways. It contains two kinase domains in the N-terminal and C-terminal region, respectively. MSK2 is activated in response to mitogenic stimuli via Erk1/2MAPK pathway and also by stress stimuli via p38MAPK pathway. Signals from mitogens and cellular stresses are involved in many functions including cell proliferation, differentiation, and survival through the phosphorylation of cyclic AMP response element-binding protein (CREB) at Ser133 which is catalyzed by MSK2. Recently, MSK2 has been shown to be required for stress-induced phosphorylation of histone H3-Ser and transcriptional activation of several immediate early genes.

Supplier: AbFrontier

Dual specificity phosphatase 13(Also known as BEDP; MDSP; TMDP; SKRP4; DUSP13A; DUSP13B) is an enzyme that in humans is encoded by the DUSP13 gene.[1]
Members of the protein tyrosine phosphatase superfamily cooperate with protein kinases to regulate cell proliferation and differentiation. This superfamily is separated into two families based on the substrate that is dephosphorylated. One family, the dual specificity phosphatases (DSPs) acts on both phosphotyrosine and phosphoserine/threonine residues. This gene encodes different but related DSP proteins through the use of non-overlapping open reading frames, alternate splicing, and presumed different transcription promoters. Expression of the distinct proteins from this gene has been found to be tissue specific and the proteins may be involved in postnatal development of specific tissues. A protein encoded by the upstream ORF was found in skeletal muscle, whereas the encoded protein from the downstream ORF was found only in testis. In mouse, a similar pattern of expression was found. Multiple alternatively spliced transcript variants were described, but the full-length sequence of only some were determined.[1]