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Product listing: Phospho-Akt (Ser473) (193H12) Rabbit mAb (Alexa Fluor® 488 Conjugate), UniProt ID P31749 #2336 to NCoR1 Antibody, UniProt ID O75376 #5948

$327
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 488 fluorescent dye and tested in-house for direct flow cytometric analysis of human cells. The unconjugated Phospho-Akt (Ser473) (193H12) Rabbit mAb #4058 reacts with phospho-Akt (Ser473) from human, mouse and rat. CST expects that Phospho-Akt (Ser473) (193H12) Rabbit mAb (Alexa Fluor® 488 Conjugate) will also recognize phospho-Akt (Ser473) in these species.
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Flow Cytometry

Background: Akt, also referred to as PKB or Rac, plays a critical role in controlling survival and apoptosis (1-3). This protein kinase is activated by insulin and various growth and survival factors to function in a wortmannin-sensitive pathway involving PI3 kinase (2,3). Akt is activated by phospholipid binding and activation loop phosphorylation at Thr308 by PDK1 (4) and by phosphorylation within the carboxy terminus at Ser473. The previously elusive PDK2 responsible for phosphorylation of Akt at Ser473 has been identified as mammalian target of rapamycin (mTOR) in a rapamycin-insensitive complex with rictor and Sin1 (5,6). Akt promotes cell survival by inhibiting apoptosis through phosphorylation and inactivation of several targets, including Bad (7), forkhead transcription factors (8), c-Raf (9), and caspase-9. PTEN phosphatase is a major negative regulator of the PI3 kinase/Akt signaling pathway (10). LY294002 is a specific PI3 kinase inhibitor (11). Another essential Akt function is the regulation of glycogen synthesis through phosphorylation and inactivation of GSK-3α and β (12,13). Akt may also play a role in insulin stimulation of glucose transport (12). In addition to its role in survival and glycogen synthesis, Akt is involved in cell cycle regulation by preventing GSK-3β-mediated phosphorylation and degradation of cyclin D1 (14) and by negatively regulating the cyclin dependent kinase inhibitors p27 Kip1 (15) and p21 Waf1/Cip1 (16). Akt also plays a critical role in cell growth by directly phosphorylating mTOR in a rapamycin-sensitive complex containing raptor (17). More importantly, Akt phosphorylates and inactivates tuberin (TSC2), an inhibitor of mTOR within the mTOR-raptor complex (18,19).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Western Blotting

Background: Flotillins belong to a family of lipid raft-associated integral membrane proteins that carry an evolutionarily conserved domain called the prohibitin homology domain (PHB) (1). Flotillin members are ubiquitously expressed and located in noncaveolar microdomains (lipid rafts) on the plasma membrane where they support signal transduction and regulate lipid raft motility and localization (2-5). Two flotillin members have been described, flotillin-1 and flotillin-2. In addition to its colocalization with lipid rafts on the plasma membrane, flotillin-1 also has been found in compartments of the endocytic and autophagosomal pathways, such as recycling/late endosomes, the Golgi complex, and the nucleus (6,7). Flotillin-2 is mainly localized to the plasma membrane and is prevalent in cell-cell contact sites. However, overexpressed flotillin-2 has also been found in the late endosome (4,8,9). Both flotillin-1 and flotillin-2 are commonly used as lipid raft-associated markers.

PhosphoPlus® Duets from Cell Signaling Technology (CST) provide a means to assess protein activation status. Each Duet contains an activation-state and total protein antibody to your target of interest. These antibodies have been selected from CST's product offering based upon superior performance in specified applications.

Background: Stat5 is activated in response to a wide variety of ligands including IL-2, GM-CSF, growth hormone and prolactin. Phosphorylation at Tyr694 is obligatory for Stat5 activation (1,2). This phosphorylation is mediated by Src upon erythropoietin stimulation (3). Stat5 is constitutively active in some leukemic cell types (4). Phosphorylated Stat5 is found in some endothelial cells treated with IL-3, which suggests its involvement in angiogenesis and cell motility (5). Stat5a and Stat5b are independently regulated and activated in various cell types. For instance, interferon treatment predominantly activates Stat5a in U-937 cells and Stat5b in HeLa cells (6).

$51
1 liter
Tris-Glycine Transfer Buffer (10X) is used as a transfer buffer during western blotting. Product is shipped and stored at room temperature.1X Formulation: 25 mM Tris, 192 mM Glycine, 20% (v/v) methanol, pH ~8.3.Note: Methanol is not supplied but is required.
APPLICATIONS

Application Methods: Western Blotting

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Chromatin IP, Immunofluorescence (Immunocytochemistry), Immunoprecipitation, Western Blotting

Background: Glucocorticoid hormones control cellular proliferation, inflammation, and metabolism through their association with the glucocorticoid receptor (GR)/NR3C1, a member of the nuclear hormone receptor superfamily of transcription factors (1). GR is composed of several conserved structural elements, including a carboxy-terminal ligand-binding domain (which also contains residues critical for receptor dimerization and hormone-dependent gene transactivation), a neighboring hinge region containing nuclear localization signals, a central zinc-finger-containing DNA-binding domain, and an amino-terminal variable region that participates in ligand-independent gene transcription. In the absence of hormone, a significant population of GR is localized to the cytoplasm in an inactive form via its association with regulatory chaperone proteins, such as HSP90, HSP70, and FKBP52. On hormone binding, GR is released from the chaperone complex and translocates to the nucleus as a dimer to associate with specific DNA sequences termed glucocorticoid response elements (GREs), thereby enhancing or repressing transcription of specific target genes (2). It was demonstrated that GR-mediated transcriptional activation is modulated by phosphorylation (3-5). Although GR can be basally phosphorylated in the absence of hormone, it becomes hyperphosphorylated upon binding receptor agonists. It has been suggested that hormone-dependent phosphorylation of GR may determine target promoter specificity, cofactor interaction, strength and duration of receptor signaling, receptor stability, and receptor subcellular localization (3).

$260
100 µl
APPLICATIONS
REACTIVITY
Bovine, Human

Application Methods: Immunohistochemistry (Paraffin), Western Blotting

Background: Endothelial nitric-oxide synthase (eNOS) is an important enzyme in the cardiovascular system. It catalyzes the production of nitric oxide (NO), a key regulator of blood pressure, vascular remodeling, and angiogenesis (1,2). The activity of eNOS is regulated by phosphorylation at multiple sites. The two most thoroughly studied sites are the activation site Ser1177 and the inhibitory site Thr495 (3). Several protein kinases including Akt/PKB, PKA, and AMPK activate eNOS by phosphorylating Ser1177 in response to various stimuli (4,5). In contrast, bradykinin and H2O2 activate eNOS activity by promoting both Ser1177 phosphorylation and Thr495 dephosphorylation (6,7).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry, Immunofluorescence (Immunocytochemistry), Immunoprecipitation, Western Blotting

Background: Brachyury protein, encoded by the T gene, is a transcription factor that is vital for the formation of posterior mesoderm and axial development during vertebrate embryogenesis (1). In the mouse, brachyury is necessary for mesodermal morphogenetic cell movements during gastrulation. Brachyury mutant mice die in utero and display deficient mesoderm formation including an abnormal notochord, missing posterior somites, and a reduced allantois (2). Human brachyury is expressed in the notochord, as well as in chordoma tumors that occur along the spine, making it a good marker for notochord and notochord-derived tumors (3,4). A common polymorphism in the human T gene has also been shown to be associated with development of the multifactorial neural tube defect, spina bifida (5,6).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: IRG1 (Immune-responsive gene 1) is one of the most up-regulated genes in macrophages under proinflammatory conditions (1). It is also highly expressed in the pregnant uterus during implantation (2,3). IRG1 is a cis-aconitate decarboxylase that produces itaconic acid by decarboxylating cis-aconic acid, an intermediate of the tricarboxylic acid cycle (4). Itaconic acid is an endogenous inhibitor of succinate dehydrogenase, linking macrophage metabolic rewiring and regulation of inflammation (5,6).

$115
20 µl
$269
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Western Blotting

Background: TNFRSF18, also known as glucocorticoid-induced tumor necrosis factor-receptor (TNFR)-related protein (GITR) and activation-inducible TNFR family receptor, encodes a type 1 membrane protein of the TNF-receptor superfamily (1). Three alternatively spliced transcript variants encoding distinct isoforms have been reported (2). GITR is an immune cell co-stimulatory receptor expressed constitutively at high levels on CD4+CD25+ T regulatory cells (Tregs), at low levels on naive and memory T cells, and is induced upon T cell activation (3-5). Studies show GITR can also be induced on NK cells, macrophages, and DCs (3, 4, 6). Although GITR does not have intrinsic enzymatic activity, TNFSF18 (also known as GITRL) expressed on antigen presenting cells binds to GITR resulting in recruitment of TNFR-associated factor family members and activation of the NF-kappa-B pathway in T cells (7). GITR ligation has been shown to play a role in CD8+ T cell activation, cytoxicity, and memory T cell survival (8-10). In the thymus, GITR is thought to play a key role in dominant immunological self-tolerance through thymic Treg differentiation and expansion (11). Of note, GITR ligation inhibits Treg suppressive function (12-13) and promotes effector T cell resistance to Treg suppression (14-15). Due to the combined effects on both Treg suppression and effector cell activation, GITR represents a unique opportunity for immunotherapeutic intervention in cancer (16).

$232
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to phycoerythrin (PE) and tested in-house for direct flow cytometry analysis in human cells. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated PD-L1 (E1L3N®) XP® Rabbit mAb #13684.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry

Background: Programmed cell death 1 ligand 1 (PD-L1, B7-H1, CD274) is a member of the B7 family of cell surface ligands that regulate T cell activation and immune responses. The PD-L1 ligand binds the PD-1 transmembrane receptor and inhibits T cell activation. PD-L1 was discovered following a search for novel B7 protein homologs and was later shown to be expressed by antigen presenting cells, activated T cells, and tissues including placenta, heart, and lung (1-3). Similar in structure to related B7 family members, PD-L1 protein contains extracellular IgV and IgC domains and a short, cytoplasmic region. Research studies demonstrate that PD-L1 is expressed in several tumor types, including melanoma, ovary, colon, lung, breast, and renal cell carcinomas (4-6). Expression of PD-L1 in cancer is associated with tumor infiltrating lymphocytes, which mediate PD-L1 expression through the release of interferon gamma (7). Additional research links PD-L1 expression to cancers associated with viral infections (8,9).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Immunoprecipitation, Western Blotting

Background: FMS-related tyrosine kinase 3 (FLT3, also called Flk2), is a member of the type III receptor tyrosine kinase family, which includes c-Kit, PDGFR and M-CSF receptors. FLT3 is expressed on early hematopoietic progenitor cells and supports growth and differentiation within the hematopoietic system (1,2). FLT3 is activated after binding with its ligand FL, which results in a cascade of tyrosine autophosphorylation and tyrosine phosphorylation of downstream targets (3). The p85 subunit of PI3 kinase, SHP2, GRB2 and Shc are associated with FLT3 after FL stimulation (4-6). Tyr589/591 is located in the juxtamembrane region of FLT3 and may play an important role in regulation of FLT3 tyrosine kinase activity. Somatic mutations of FLT3 consisting of internal tandem duplications (ITDs) occur in 20% of patients with acute myeloid leukemia (7).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: HGK (MAP4K4 or mitogen-activated protein kinase kinase kinase kinase 4) is a serine/threonine kinase that belongs to the mammalian STE20/MAP4K kinase family involved in response to environmental stress and cytokines such as TNF-α (1-3). HGK specifically activates the c-Jun N-terminal kinase (JNK) signaling pathway and increases AP-1-mediated transcriptional activity in vivo (1). HGK is broadly expressed in many types of human cancer and cancer cell lines and plays an important role in cell transformation, invasiveness, adhesion and migration (4,5).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Western Blotting

Background: HER3/ErbB3 is a member of the ErbB receptor protein tyrosine kinase family, but it lacks tyrosine kinase activity. Tyrosine phosphorylation of ErbB3 depends on its association with other ErbB tyrosine kinases. Upon ligand binding, heterodimers form between ErbB3 and other ErbB proteins, and ErbB3 is phosphorylated on tyrosine residues by the activated ErbB kinase (1,2). There are at least 9 potential tyrosine phosphorylation sites in the carboxy-terminal tail of ErbB3. These sites serve as consensus binding sites for signal transducing proteins, including Src family members, Grb2, and the p85 subunit of PI3 kinase, which mediate ErbB downstream signaling (3). Both Tyr1222 and Tyr1289 of ErbB3 reside within a YXXM motif and participate in signaling to PI3K (4).Investigators have found that ErbB3 is highly expressed in many cancer cells (5) and activation of the ErbB3/PI3K pathway is correlated with malignant phenotypes of adenocarcinomas (6). Research studies have demonstrated that in tumor development, ErbB3 may function as an oncogenic unit together with other ErbB members (e.g. ErbB2 requires ErbB3 to drive breast tumor cell proliferation) (7). Thus, investigators view inhibiting interaction between ErbB3 and ErbB tyrosine kinases as a novel strategy for anti-tumor therapy.

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Western Blotting

Background: CD8+ cytotoxic T cells recognize peptides presented by MHC class I molecules on the surface of infected cells and tumor cells. The transporters associated with antigen processing 1 and 2 (TAP1 and TAP2) form the TAP complex which resides on the ER membrane and transports peptides from the cytoplasm into the ER for loading onto MHC class I molecules (1-8). In addition, TAP localized to endosomal membranes is important for cross-presentation by dendritic cells (9,10). IFN-γ produced by T cells and NK cells in response to infection causes upregulation of TAP1 and TAP2, resulting in increased antigen presentation to T cells (11). Some viral proteins inhibit TAP function or downregulate TAP expression resulting in viral immune evasion (12,13). In addition, investigators have observed reduced TAP expression in a variety of tumor types, and it is thought to be one mechanism for tumor immune evasion (14).

$111
20 µl
$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry, Immunofluorescence (Immunocytochemistry), Immunohistochemistry (Paraffin), Western Blotting

Background: TRA-1-60 and TRA-1-81 antibodies detect antigens present on the surface of human stem, teratocarcinoma, and embryonic germ cells (1). TRA-1-60(S) reacts with a neuraminidase sensitive epitope of a proteoglycan (2,3), while TRA-1-81 reacts with a neuraminidase insensitive epitope on the same antigen. Recently this antigen has been proposed to be a form of the protein podocalyxin (4). TRA-1-60 is also detected in the serum of patients with germ cell tumors (5,6).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: Protein ubiquitination requires the concerted action of the E1, E2, and E3 ubiquitin-conjugating enzymes. Ubiquitin is first activated through ATP-dependent formation of a thiol ester with ubiquitin-activating enzyme E1. The activated ubiquitin is then transferred to a thiol group of ubiquitin-carrier enzyme E2. The final step is the transfer of ubiquitin from E2 to an ε-amino group of the target protein lysine residue, which is mediated by ubiquitin-ligase enzyme E3 (1).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Immunofluorescence (Immunocytochemistry), Immunohistochemistry (Paraffin), Immunoprecipitation, Western Blotting

Background: Protein ubiquitination and deubiquitination are reversible processes catalyzed by ubiquitinating enzymes (UBEs) and deubiquitinating enzymes (DUBs) respectively (1,2). DUBs are categorized into five subfamilies-USP, UCH, OTU, MJD, and JAMM. Ubiquitin-specific protease 9, X-linked (USP9X) possesses a well-conserved catalytic domain with cysteine peptidase activity, which allows for cleavage of ubiquitin and polyubiquitin conjugates. USP9X is the mammalian homolog of the Drosophila fat-facets (faf) gene, which is essential for normal eye development and viability of the early fly embryo (3,4). While USP9X expression is also critical for normal mammalian development (5-7), many of its substrates are only beginning to be elucidated. There is mounting evidence that USP9X functions in the formation of epithelial cell-cell contacts through deubiquitination-dependent stabilization of molecules involved in maintaining the integrity of both adherens and tight junctions. Indeed, USP9X has been found to associate with AF-6, the β-catenin-E-cadherin complex, and EFA6 (8-11). Research studies have also demonstrated that USP9X is an integral component of the TGF-β/BMP signaling cascade by opposing TRIM33-mediated monoubiquitination of SMAD4 (12). USP9X is overexpressed in a variety of human cancers and contributes to enhanced cell survival, in part, through its ability to deubiquitinate and stabilize the Mcl-1 oncoprotein (13). There is some evidence, however, that suggests the role of USP9X in tumorigenesis is context dependent. Research studies have implicated USP9X in a tumor suppressor role during the early stages of pancreatic ductal adenocarcinoma (PDAC) and in an oncogenic role during advanced stages of PDAC (14,15).

$364
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 647 fluorescent dye and tested in-house for direct flow cytometric analysis in human cells. This antibody is expected to exhibit the same species cross-reactivity as the unconjugated Phospho-TBK1/NAK (Ser172) (D52C2) XP® Rabbit mAb #5483.
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Flow Cytometry

Background: TBK1 (TANK-binding kinase 1)/NAK (NF-κB activating kinase) is an IκB kinase (IKK)-activating kinase and can activate IKK through direct phosphorylation (1). TBK1 was identified through association with the TRAF binding protein, TANK, and found to function upstream of NIK and IKK in the activation of NF-κB (2). TBK1 induces IκB degradation and NF-κB activity through IKKβ. TBK1 may mediate IKK and NF-κB activation in response to growth factors that stimulate PKCε activity (1). TBK1 plays a pivotal role in the activation of IRF3 in the innate immune response (3).

$348
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 555 fluorescent dye and tested in-house for immunofluorescent analysis in human cells. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated Vimentin (D21H3) XP® Rabbit mAb #5741.
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Immunofluorescence (Immunocytochemistry)

Background: The cytoskeleton consists of three types of cytosolic fibers: microfilaments (actin filaments), intermediate filaments, and microtubules. Major types of intermediate filaments are distinguished by their cell-specific expression: cytokeratins (epithelial cells), glial fibrillary acidic protein (GFAP) (glial cells), desmin (skeletal, visceral, and certain vascular smooth muscle cells), vimentin (mesenchyme origin), and neurofilaments (neurons). GFAP and vimentin form intermediate filaments in astroglial cells and modulate their motility and shape (1). In particular, vimentin filaments are present at early developmental stages, while GFAP filaments are characteristic of differentiated and mature brain astrocytes. Thus, GFAP is commonly used as a marker for intracranial and intraspinal tumors arising from astrocytes (2). Research studies have shown that vimentin is present in sarcomas, but not carcinomas, and its expression is examined in conjunction with that of other markers to distinguish between the two (3). Vimentin's dynamic structural changes and spatial re-organization in response to extracellular stimuli help to coordinate various signaling pathways (4). Phosphorylation of vimentin at Ser56 in smooth muscle cells regulates the structural arrangement of vimentin filaments in response to serotonin (5,6). Remodeling of vimentin and other intermediate filaments is important during lymphocyte adhesion and migration through the endothelium (7).During mitosis, CDK1 phosphorylates vimentin at Ser56. This phosphorylation provides a PLK binding site for vimentin-PLK interaction. PLK further phosphorylates vimentin at Ser82, which might serve as memory phosphorylation site and play a regulatory role in vimentin filament disassembly (8,9). Additionally, studies using various soft-tissue sarcoma cells have shown that phosphorylation of vimentin at Ser39 by Akt1 enhances cell migration and survival, suggesting that vimentin could be a potential target for soft-tissue sarcoma targeted therapy (10,11).

$303
100 µl
APPLICATIONS
REACTIVITY
All Species Expected

Application Methods: Immunoprecipitation, Western Blotting

Background: Ataxia telangiectasia mutated kinase (ATM) and ataxia telangiectasia and Rad3-related kinase (ATR) are related kinases that regulate cell cycle checkpoints and DNA repair (1). The identified substrates for ATM are p53, p95/NBS1, MDM2, Chk2, BRCA1, CtIP, 4E-BP1, and Chk1 (1,2) The essential requirement for the substrates of ATM/ATR is S*/T*Q. Hydrophobic amino acids at positions -3 and -1, and negatively charged amino acids at position +1 are positive determinants for substrate recognition by these kinases. Positively charged residues surrounding the S*/T*Q are negative determinants for substrate phosphorylation (3). The complex phenotype of AT cells suggests that it likely has additional substrates (3). To better understand the kinase and identify substrates for ATM and the related kinase ATR, CST has developed antibodies that recognize phosphorylated serine or threonine in the S*/T*Q motif.

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: Methylation of DNA at cytosine residues in mammalian cells is a heritable, epigenetic modification that is critical for proper regulation of gene expression, genomic imprinting and development (1,2). Three families of mammalian DNA methyltransferases have been identified: DNMT1, DNMT2 and DNMT3 (1,2). DNMT1 is constitutively expressed in proliferating cells and functions as a maintenance methyltransferase, transferring proper methylation patterns to newly synthesized DNA during replication. DNMT3A and DNMT3B are strongly expressed in embryonic stem cells with reduced expression in adult somatic tissues. DNMT3A and DNMT3B function as de novo methyltransferases that methylate previously unmethylated regions of DNA. DNMT2 is expressed at low levels in adult somatic tissues and its inactivation affects neither de novo nor maintenance DNA methylation. DNMT1, DNMT3A and DNMT3B together form a protein complex that interacts with histone deacetylases (HDAC1, HDAC2, Sin3A), transcriptional repressor proteins (RB, TAZ-1) and heterochromatin proteins (HP1, SUV39H1), to maintain proper levels of DNA methylation and facilitate gene silencing (3-8). Improper DNA methylation contributes to diseased states such as cancer (1,2). Hypermethylation of promoter CpG islands within tumor suppressor genes correlates with gene silencing and the development of cancer. In addition, hypomethylation of bulk genomic DNA correlates with and may contribute to the onset of cancer. DNMT1, DNMT3A and DNMT3B are over-expressed in many cancers, including acute and chronic myelogenous leukemias, in addition to colon, breast and stomach carcinomas (9-12).

$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: The Eph receptors are the largest known family of receptor tyrosine kinases (RTKs). They can be divided into two groups based on sequence similarity and on their preference for a subset of ligands: EphA receptors bind to a glycosylphosphatidylinositol-anchored ephrin A ligand; EphB receptors bind to ephrin B proteins that have a transmembrane and cytoplasmic domain (1,2). Research studies have shown that Eph receptors and ligands may be involved in many diseases including cancer (3). Both ephrin A and B ligands have dual functions. As RTK ligands, ephrins stimulate the kinase activity of Eph receptors and activate signaling pathways in receptor-expressing cells. The ephrin extracellular domain is sufficient for this function as long as it is clustered (4). The second function of ephrins has been described as "reverse signaling", whereby the cytoplasmic domain becomes tyrosine phosphorylated, allowing interactions with other proteins that may activate signaling pathways in the ligand-expressing cells (5). Various stimuli can induce tyrosine phosphorylation of ephrin B, including binding to EphB receptors, activation of Src kinase, and stimulation by PDGF and FGF (6). Tyr324 and Tyr327 have been identified as major phosphorylation sites of ephrin B1 in vivo (7).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Flow Cytometry, Immunofluorescence (Immunocytochemistry), Immunohistochemistry (Paraffin), Immunoprecipitation, Western Blotting

Background: The homeodomain protein NKX6.1 is a transcription factor that regulates pancreatic β-cell development (1). Overexpressed NKX6.1 stimulates rat pancreatic β-cell proliferation and increases glucose-stimulated insulin secretion (GSIS) (2). The effect on GSIS was shown to be mediated by the up-regulation of prohormone VGF expression and the subsequent potentiation by TLQP-21, a peptide derived from VGF (3). Both nuclear receptors Nr4a1 and Nr4a3 are essential for pancreatic β-cell proliferation driven by overexpressed NKX6.1 (4). In addition, studies suggest that NKX6.1 is a suppressor for epithelial-to-mesenchymal transition (EMT), leading to inhibition of tumor metastasis (5).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry, Immunofluorescence (Immunocytochemistry), Immunoprecipitation, Western Blotting

Background: Inhibitor of DNA-binding/Differentiation (ID) proteins are a family of proteins that function to repress the activity of basic helix-loop-helix (bHLH) transcription factors. There are four known ID proteins in humans (ID1-4), all of which contain a helix-loop-helix domain but lack a basic DNA binding domain. Heterodimerization with bHLH transcription factors therefore functions to sequester bHLH proteins and prevent their binding to DNA (1). ID proteins play important functional roles in development, primarily by inhibiting premature differentiation of stem/progenitor cells (1,2). ID3 plays an important role in immune system development where it has been shown to repress E2A-mediated differentiation of T cells (3). Studies in mouse models have shown that homozygous deletion of ID3 disrupts regulatory T cell differentiation (4) and leads to development of γδ T cell lymphoma (5). Outside of the hematopoietic compartment, ID3 was shown to repress MyoD, implicating ID3 in TGFβ-mediated muscle repair (6). Similarly, research studies have shown that ID3 suppresses p21 in colon cancer cells, a function that is purported to promote the self-renewal capacity of putative cancer-initiating cells (7).

$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Type I insulin-like growth factor receptor (IGF-IR) is a transmembrane receptor tyrosine kinase that is widely expressed in many cell lines and cell types within fetal and postnatal tissues (1-3). Receptor autophosphorylation follows binding of the IGF-I and IGF-II ligands. Three tyrosine residues within the kinase domain (Tyr1131, Tyr1135, and Tyr1136) are the earliest major autophosphorylation sites (4). Phosphorylation of these three tyrosine residues is necessary for kinase activation (5,6). Insulin receptors (IRs) share significant structural and functional similarity with IGF-I receptors, including the presence of an equivalent tyrosine cluster (Tyr1146/1150/1151) within the kinase domain activation loop. Tyrosine autophosphorylation of IRs is one of the earliest cellular responses to insulin stimulation (7). Autophosphorylation begins with phosphorylation at Tyr1146 and either Tyr1150 or Tyr1151, while full kinase activation requires triple tyrosine phosphorylation (8).

The Phospho-Chk1/2 Antibody Sampler Kit offers an economical means to evaluate the phosphorylation status of Chk1 and Chk2 on multiple residues. The kit contains enough primary and secondary antibodies to perform two Western blot experiments with each primary antibody.

Background: Chk1 kinase acts downstream of ATM/ATR kinase and plays an important role in DNA damage checkpoint control, embryonic development, and tumor suppression (1). Activation of Chk1 involves phosphorylation at Ser317 and Ser345 by ATM/ATR, followed by autophosphorylation of Ser296. Activation occurs in response to blocked DNA replication and certain forms of genotoxic stress (2). While phosphorylation at Ser345 serves to localize Chk1 to the nucleus following checkpoint activation (3), phosphorylation at Ser317 along with site-specific phosphorylation of PTEN allows for re-entry into the cell cycle following stalled DNA replication (4). Chk1 exerts its checkpoint mechanism on the cell cycle, in part, by regulating the cdc25 family of phosphatases. Chk1 phosphorylation of cdc25A targets it for proteolysis and inhibits its activity through 14-3-3 binding (5). Activated Chk1 can inactivate cdc25C via phosphorylation at Ser216, blocking the activation of cdc2 and transition into mitosis (6). Centrosomal Chk1 has been shown to phosphorylate cdc25B and inhibit its activation of CDK1-cyclin B1, thereby abrogating mitotic spindle formation and chromatin condensation (7). Furthermore, Chk1 plays a role in spindle checkpoint function through regulation of aurora B and BubR1 (8). Research studies have implicated Chk1 as a drug target for cancer therapy as its inhibition leads to cell death in many cancer cell lines (9).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: Smad ubiquitin regulatory factor 2 (Smurf2) is a HECT domain E3 ubiquitin ligase. It was initially identified as an inhibitor of TGF-β/BMP signaling by targeting R-Smads and TGF type I receptor for ubiquitination and degradation (1-3). Subsequent studies have revealed its role in neuronal and planar cell polarity, as well as in the senescence response and suppression of tumorigenesis (4-8). Smurf2 has a broad range of substrates including RUNX2, AMSH, Rap1B, and RNF11 (5,9-11). Smurf2 is widely expressed in various tissues. The C2 domain of Smurf2 inhibits its catalytic activity by interacting with the HECT domain (12). Research studies have shown that Smurf2 functions as a tumor suppressor by maintaining genomic stability through targeting RNF20 (13).

$327
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 488 fluorescent dye and tested in-house for direct flow cytometric and immunofluorescent analysis in human cells. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated Phospho-STING (Ser366) (D8K6H) Rabbit mAb #40818.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry, Immunofluorescence (Immunocytochemistry)

Background: Stimulator of interferon genes (STING, TMEM173, MITA) is a transmembrane adaptor protein that is a critical component of the cellular innate immune response to pathogenic cytoplasmic DNA (1,2). STING is a ubiquitously expressed protein found predominantly in the ER (1). The enzyme cGAMP synthase (cGAS) produces the second messenger cyclic-GMP-AMP (cGAMP) in response to cytoplasmic DNA (3,4). cGAMP binds and activates STING (3,4). In addition, detection of cytoplasmic DNA by nucleic acid sensors, including DDX41 or IFI16, results in STING activation (5,6). Following activation, STING translocates with TBK1 to perinuclear endosomes (7). The TBK1 kinase phosphorylates and activates interferon regulatory factors (IRFs) and NF-κB, which leads to the induction of type I interferon and other immune response genes (1,2,7).

$305
400 µl
This Cell Signaling Technology antibody is immobilized via covalent binding of primary amino groups to N-hydroxysuccinimide (NHS)-activated sepharose beads. Rictor (D16H9) Rabbit mAb (Sepharose Bead Conjugate) is useful for immunoprecipitation assays. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated Rictor (D16H9) Rabbit mAb #9476.
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Immunoprecipitation

Background: Cell growth is a fundamental biological process whereby cells accumulate mass and increase in size. The mammalian TOR (mTOR) pathway regulates growth by coordinating energy and nutrient signals with growth factor-derived signals (1). mTOR is a large protein kinase with two different complexes. One complex contains mTOR, GβL and raptor, which is a target of rapamycin. The other complex, insensitive to rapamycin, includes mTOR, GβL, Sin1, and rictor (1). The mTOR-rictor complex phosphorylates Ser473 of Akt/PKB in vitro (2). This phosphorylation is essential for full Akt/PKB activation. Furthermore, an siRNA knockdown of rictor inhibits Ser473 phosphorylation in 3T3-L1 adipocytes (3). This complex has also been shown to phosphorylate the rapamycin-resistant mutants of S6K1, another effector of mTOR (4).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Western Blotting

Background: The most well characterized nuclear receptor corepressors are SMRT (silencing mediator for retinoic acid and thyroid hormone receptors) and its close paralog NCoR1 (nuclear receptor corepressor) (1,2). NCoR1 functions to transcriptionally silence various unliganded, DNA bound non-steroidal nuclear receptors by serving as a large molecular scaffold that bridges the receptors with multiple chromatin remodeling factors that repress nuclear receptor-mediated gene transcription, in part, through deacetylation of core histones surrounding target promoters. Indeed, the N-terminal portion of NCoR1 possesses multiple distinct transcriptional repression domains (RDs) reponsible for the recruitment of additional components of the corepressor complex such as HDACs, mSin3, GPS2, and TBL1/TBLR1. In between the RDs lies a pair of potent repressor motifs known as SANT motifs (SWI3, ADA2, N-CoR, and TFIIIB), which recruit HDAC3 and histones to the repressor complex in order to enhance HDAC3 activity (3). The C-terminal portion of NCoR1 contains multiple nuclear receptor interaction domains (NDs), each of which contains a conserved CoRNR box (or L/I-X-X-I/V-I) motif that allow for binding to various unliganded nuclear hormone receptors such as thyroid hormone (THR) and retinoic acid (RAR) receptors (4,5).Recent genetic studies in mice have not only corroborated the wealth of biochemical studies involving NCoR1 but have also provided significant insight regarding the function of NCoR1 in mammalian development and physiology. Although it has been observed that loss of Ncor1 does not affect early embyonic development, likely due to compensation by Smrt, embryonic lethality ultimately results during mid-gestation, largely due to defects in erythropoesis and thymopoesis (6). Another study demonstrated that the NDs of NCoR1 are critical for its ability to function in a physiological setting as a transcriptional repressor of hepatic THR and Liver X Receptor (LXR) (7).