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Product listing: PhosphoPlus® Btk (Tyr223) Antibody Duet, UniProt ID Q06187 #79781 to Phospho-ATRIP (Ser224) Antibody, UniProt ID Q8WXE1 #5161

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: Bruton's tyrosine kinase (Btk) is a member of the Btk/Tec family of cytoplasmic tyrosine kinases. Like other Btk family members, it contains a pleckstrin homology (PH) domain and Src homology SH3 and SH2 domains. Btk plays an important role in B cell development (1,2). Activation of B cells by various ligands is accompanied by Btk membrane translocation mediated by its PH domain binding to phosphatidylinositol-3,4,5-trisphosphate (3-5). The membrane-localized Btk is active and associated with transient phosphorylation of two tyrosine residues, Tyr551 and Tyr223. Tyr551 in the activation loop is transphosphorylated by the Src family tyrosine kinases, leading to autophosphorylation at Tyr223 within the SH3 domain, which is necessary for full activation (6,7). The activation of Btk is negatively regulated by PKCβ through phosphorylation of Btk at Ser180, which results in reduced membrane recruitment, transphosphorylation, and subsequent activation (8). The PKC inhibitory signal is likely to be a key determinant of the B cell receptor signaling threshold to maintain optimal Btk activity (8).

This peptide is used to specifically block Src Antibody #2108 and Src (36D10) Rabbit mAb #2109 reactivity.

Background: The Src family of protein tyrosine kinases, which includes Src, Lyn, Fyn, Yes, Lck, Blk, and Hck, are important in the regulation of growth and differentiation of eukaryotic cells (1). Src activity is regulated by tyrosine phosphorylation at two sites, but with opposing effects. While phosphorylation at Tyr416 in the activation loop of the kinase domain upregulates enzyme activity, phosphorylation at Tyr527 in the carboxy-terminal tail by Csk renders the enzyme less active (2).

$489
96 assays
1 Kit
The PathScan® Total α-Synuclein Sandwich ELISA Kit is a solid phase sandwich enzyme-linked immunosorbent assay (ELISA) that detects endogenous levels ofα-Synuclein protein. An α-Synuclein rabbit mAb has been coated onto the microwells. After incubation with cell lysates, the α-Synuclein protein is captured by the coated antibody. Following extensive washing, α-Synuclein mouse detection mAb is added to detect captured α-Synuclein protein. Anti-mouse, HRP-linked antibody is then used to recognize the bound detection antibody. HRP substrate, TMB, is added to develop color. The magnitude of absorbance for the developed color is proportional to the quantity of α-Synuclein protein. Antibodies in the kit are custom formulations specific to the kit.
REACTIVITY
Mouse, Rat

Background: α-Synuclein is a protein of 140-amino acids expressed abundantly in the brain. α-Synuclein is also the main component of pathogenic Lewy bodies and Lewy neurites. Research studies have shown that mutations of the α-synuclein gene are linked to Parkinson's disease (1).

$489
96 assays
1 Kit
CST's PathScan® Phospho-c-Kit (Tyr719) Sandwich ELISA Kit is a solid phase sandwich enzyme-linked immunosorbent assay (ELISA) that detects endogenous levels of c-Kit protein when phosphorylated at Tyr719. A c-Kit Mouse mAb has been coated onto the microwells. After incubation with cell lysates, both phospho- and nonphospho-c-Kit proteins are captured by the coated antibody. Following extensive washing, Phospho-c-Kit (Tyr719) Rabbit Antibody is added to detect the captured phospho-c-Kit protein. Anti-rabbit IgG HRP-linked Antibody #7074 is then used to recognize the bound detection antibody. HRP substrate, TMB, is added to develop color. The magnitude of absorbance for this developed color is proportional to the quantity of c-Kit protein phosphorylated at Tyr719.Antibodies in kit are custom formulations specific to kit.
REACTIVITY
Human

Background: c-Kit is a member of the subfamily of receptor tyrosine kinases that includes PDGF, CSF-1, and FLT3/flk-2 receptors (1,2). It plays a critical role in activation and growth in a number of cell types including hematopoietic stem cells, mast cells, melanocytes, and germ cells (3). Upon binding with its stem cell factor (SCF) ligand, c-Kit undergoes dimerization/oligomerization and autophosphorylation. Activation of c-Kit results in the recruitment and tyrosine phosphorylation of downstream SH2-containing signaling components including PLCγ, the p85 subunit of PI3 kinase, SHP2, and CrkL (4). Molecular lesions that impair the kinase activity of c-Kit are associated with a variety of developmental disorders (5), and mutations that constitutively activate c-Kit can lead to pathogenesis of mastocytosis and gastrointestinal stromal tumors (6). Tyr719 is located in the kinase insert region of the catalytic domain. c-Kit phosphorylated at Tyr719 binds to the p85 subunit of PI3 kinase in vitro and in vivo (7).

$364
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to phycoerythrin (PE) 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 EGF Receptor (E746-A750del Specific) (D6B6) XP® Rabbit mAb #2085.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry

Background: The epidermal growth factor (EGF) receptor is a 170 kDa transmembrane tyrosine kinase that belongs to the HER/ErbB protein family. Research studies have shown that somatic mutations in the tyrosine kinase domain of EGF receptor (EGFR) are present in a subset of lung adenocarinomas that respond to EGFR inhibitors, such as gefinitib and erlotinib (1-3). Two types of mutations account for approximately 90% of mutated cases: a specific point mutation, L858R, that occurs in exon 21 and short in-frame deletions in exon 19 (4,5). The most frequent exon 19 deletion is E746-A750, accounting for 90% of lesions at this site, although some rare variants occur.

$489
96 assays
1 Kit
CST's PathScan® Phospho-PTEN (Ser380) Sandwich ELISA Kit is a solid phase sandwich enzyme-linked immunosorbent assay (ELISA) that detects endogenous levels of phospho-PTEN (Ser380) protein. A PTEN Mouse mAb has been coated onto the microwells. After incubation with cell lysates, PTEN protein (phospho and non-phospho) is captured by the coated antibody. Following extensive washing, Phospho-PTEN (Ser380) Antibody is added to detect the captured phospho-PTEN (Ser380) protein. Anti-rabbit IgG, HRP-linked Antibody is then used to recognize the bound detection antibody. HRP substrate, TMB, is added to develop color. The magnitude of absorbance for this developed color is proportional to the quantity of phospho-PTEN (Ser380) protein.Antibodies in kit are custom formulations specific to kit.
REACTIVITY
Human, Monkey, Mouse

Background: PTEN (phosphatase and tensin homologue deleted on chromosome ten), also referred to as MMAC (mutated in multiple advanced cancers) phosphatase, is a tumor suppressor implicated in a wide variety of human cancers (1). PTEN encodes a 403 amino acid polypeptide originally described as a dual-specificity protein phosphatase (2). The main substrates of PTEN are inositol phospholipids generated by the activation of the phosphoinositide 3-kinase (PI3K) (3). PTEN is a major negative regulator of the PI3K/Akt signaling pathway (1,4,5). PTEN possesses a carboxy-terminal, noncatalytic regulatory domain with three phosphorylation sites (Ser380, Thr382, and Thr383) that regulate PTEN stability and may affect its biological activity (6,7). PTEN regulates p53 protein levels and activity (8) and is involved in G protein-coupled signaling during chemotaxis (9,10).

$469
Reagents for 4 x 96 well plates
1 Kit
CST's PathScan® Phospho-c-Jun (Ser63) Sandwich ELISA Antibody Pair is offered as an alternative to our PathScan® Phospho-c-Jun (Ser63) Sandwich ELISA Kit #7145. Capture and Detection antibodies (100X stocks) and a HRP-conjugated secondary antibody (1000X stock) are supplied. Sufficient reagents are provided for performing 4 x 96 well ELISAs. Phospho-c-Jun (Ser63) Capture Antibody is coated in PBS overnight in a 96 well microplate. After blocking, cell lysates are added, followed by c-Jun Detection Antibody and HRP-conjugated secondary antibody. HRP substrate, TMB, is added for color development. The magnitude of the absorbance at 450 nm is proportional to the quantity of phospho-c-jun (Ser63) protein.Antibodies in kit are custom formulations specific to kit.
REACTIVITY
Human, Mouse, Rat

Background: c-Jun is a member of the Jun family containing c-Jun, JunB, and JunD, and is a component of the transcription factor activator protein-1 (AP-1). AP-1 is composed of dimers of Fos, Jun, and ATF family members and binds to and activates transcription at TRE/AP-1 elements (reviewed in 1). Extracellular signals including growth factors, chemokines, and stress activate AP-1-dependent transcription. The transcriptional activity of c-Jun is regulated by phosphorylation at Ser63 and Ser73 through SAPK/JNK (reviewed in 2). Knock-out studies in mice have shown that c-Jun is essential for embryogenesis (3), and subsequent studies have demonstrated roles for c-Jun in various tissues and developmental processes including axon regeneration (4), liver regeneration (5), and T cell development (6). AP-1 regulated genes exert diverse biological functions including cell proliferation, differentiation, and apoptosis, as well as transformation, invasion and metastasis, depending on cell type and context (7-9). Other target genes regulate survival, as well as hypoxia and angiogenesis (8,10). Research studies have implicated c-Jun as a promising therapeutic target for cancer, vascular remodeling, acute inflammation, and rheumatoid arthritis (11,12).

$348
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. This antibody is expected to exhibit the same species cross-reactivity as the unconjugated FoxP1 (D35D10) XP® Rabbit mAb #4402.
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Flow Cytometry

Background: Forkhead box (Fox) proteins are a family of evolutionarily conserved transcription factors containing a sequence known as Forkhead box or winged helix DNA binding domain (1). The human genome contains 43 Fox proteins that are divided into subfamilies. The FoxP subfamily has four members, FoxP1 - FoxP4, which are broadly expressed and play important roles in organ development, immune response and cancer pathogenesis (2-4). The FoxP subfamily has several characteristics that are atypical among Fox proteins: their Forkhead domain is located at the carboxy-terminal region and they contain motifs that promote homo- and heterodimerization. FoxP proteins usually function as transcriptional repressors (4,5).

$499
96 assays
1 Kit
The FastScan™ Phospho-Akt (Ser473) ELISA Kit is a sandwich enzyme-linked immunosorbent assay (ELISA) that detects endogenous levels of Akt when phosphorylated at Ser473. To perform the assay, sample is incubated with a capture antibody conjugated with a proprietary tag and a second detection antibody linked to HRP, forming a sandwich with phospho-Akt (Ser473) in solution. This entire complex is immobilized to the plate via an anti-tag antibody. The wells are then washed to remove unbound material. TMB is then added. The magnitude of observed signal is proportional to the quantity of phospho-Akt (Ser473). Antibodies in kit are custom formulations specific to kit.
REACTIVITY
Human, Monkey, Mouse, Rat

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).

$348
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 Galectin-9 (D9R4A) XP® Rabbit mAb #54330.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry

Background: Galectins are a family of β-galactose binding proteins that are characterized by an affinity for poly-N-acetyllactosamine-enriched glycoconjugates and a carbohydrate-binding site (1,2). Members of the galectin family have been implicated in a variety of biological functions, including cell adhesion (3), growth regulation (4), cytokine production (5), T-cell apoptosis (6), and immune responses (7).Galectin-9 is induced by proinflammatory stimuli, including IFN-γ, TNF-α, and TLR ligands, and regulates various immune responses through interaction with its ligand TIM-3 (8, 9). Binding of galectin-9 to TIM-3 expressed by Th1 CD4 T cells resulted in T cell death (9). On the other hand, galectin-9 treatment of tumor-bearing mice increased the number of IFN-γ-producing TIM-3+ CD8 T cells and TIM-3+ dendritic cells (10). Transgenic overexpression of either TIM-3 or galectin-9 in mice led to an increase in cells with a myeloid-derived suppressor cell phenotype and inhibition of immune responses (11). CD44 is also proposed to be a receptor for galectin-9, and interaction of galectin-9 with CD44 expressed by induced regulatory T (iTreg) cells enhanced the stability of function of iTreg cells. In addition, galectin-9 was recently demonstrated to bind Dectin-1 expressed by pancreatic ductal adenocarcinoma-infiltrating macrophages, resulting in tolerogenic macrophage reprogramming and suppression of anti-tumor immunity. Increased galectin-9 expression has been observed in several cancer types, including lung, liver, breast, and kidney (12). Alternative splicing of the galectin-9 transcript leads to several isoforms (13).

$348
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. This antibody is expected to exhibit the same species cross-reactivity as the unconjugated Met (D1C2) XP® Rabbit mAb #8198.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry

Background: Met, a high affinity tyrosine kinase receptor for hepatocyte growth factor (HGF, also known as scatter factor) is a disulfide-linked heterodimer made of 45 kDa α- and 145 kDa β-subunits (1,2). The α-subunit and the amino-terminal region of the β-subunit form the extracellular domain. The remainder of the β-chain spans the plasma membrane and contains a cytoplasmic region with tyrosine kinase activity. Interaction of Met with HGF results in autophosphorylation at multiple tyrosines, which recruit several downstream signaling components, including Gab1, c-Cbl, and PI3 kinase (3). These fundamental events are important for all of the biological functions involving Met kinase activity. The addition of a phosphate at cytoplasmic Tyr1003 is essential for Met protein ubiquitination and degradation (4). Phosphorylation at Tyr1234/1235 in the Met kinase domain is critical for kinase activation. Phosphorylation at Tyr1349 in the Met cytoplasmic domain provides a direct binding site for Gab1 (5). Research studies have shown that altered Met levels and/or tyrosine kinase activities are found in several types of tumors, including renal, colon, and breast. Thus, investigators have concluded that Met is an attractive potential cancer therapeutic and diagnostic target (6,7).

$489
96 assays
1 Kit
CST's PathScan® Total MEK1 Sandwich ELISA Kit is a solid phase sandwich enzyme-linked immunosorbent assay (ELISA) that detects endogenous levels of total MEK1 protein. A MEK1 mouse mAb has been coated onto the microwells. After incubation with cell lysates, total MEK1 protein (phospho- and nonphospho-) is captured by the coated antibody. Following extensive washing, MEK1/2 Antibody is added to detect the captured MEK1 protein. HRP-linked, anti-rabbit antibody #7074 is then used to recognize the bound detection antibody. HRP substrate, TMB, is added to develop color. The magnitude of optical density for this developed color is proportional to the quantity of total MEK1 protein.Antibodies in kit are custom formulations specific to kit.
REACTIVITY
Human, Mouse

Background: MEK1 and MEK2, also called MAPK or Erk kinases, are dual-specificity protein kinases that function in a mitogen activated protein kinase cascade controlling cell growth and differentiation (1-3). Activation of MEK1 and MEK2 occurs through phosphorylation of two serine residues at positions 217 and 221, located in the activation loop of subdomain VIII, by Raf-like molecules. MEK1/2 is activated by a wide variety of growth factors and cytokines and also by membrane depolarization and calcium influx (1-4). Constitutively active forms of MEK1/2 are sufficient for the transformation of NIH/3T3 cells or the differentiation of PC-12 cells (4). MEK activates p44 and p42 MAP kinase by phosphorylating both threonine and tyrosine residues at sites located within the activation loop of kinase subdomain VIII.

$489
96 assays
1 Kit
The PathScan® Phospho-HER2/ErbB2 (panTyr) Sandwich ELISA Kit is a solid phase sandwich enzyme-linked immunosorbent assay (ELISA) that detects endogenous levels of tyrosine-phosphorylated HER2/ErbB2 protein. A HER2/ErbB2 rabbit mAb has been coated on the microwells. After incubation with cell lysates, HER2/ErbB2 protein (phospho and nonphospho) is captured by the coated antibody. Following extensive washing, a phospho-tyrosine mouse detection antibody is added to detect captured tyrosine-phosphorylated HER2/ErbB2 protein. Anti-mouse IgG, HRP-linked antibody is then used to recognize the bound detection antibody. HRP substrate, TMB, is added to develop color. The magnitude of the absorbance for this developed color is proportional to the quantity of HER2/ErbB2 protein phosphorylated on tyrosine.Antibodies in kit are custom formulations specific to kit.
REACTIVITY
Human

Background: The ErbB2 (HER2) proto-oncogene encodes a 185 kDa transmembrane, receptor-like glycoprotein with intrinsic tyrosine kinase activity (1). While ErbB2 lacks an identified ligand, ErbB2 kinase activity can be activated in the absence of a ligand when overexpressed and through heteromeric associations with other ErbB family members (2). Amplification of the ErbB2 gene and overexpression of its product are detected in almost 40% of human breast cancers (3). Binding of the c-Cbl ubiquitin ligase to ErbB2 at Tyr1112 leads to ErbB2 poly-ubiquitination and enhances degradation of this kinase (4). ErbB2 is a key therapeutic target in the treatment of breast cancer and other carcinomas and targeting the regulation of ErbB2 degradation by the c-Cbl-regulated proteolytic pathway is one potential therapeutic strategy. Phosphorylation of the kinase domain residue Tyr877 of ErbB2 (homologous to Tyr416 of pp60c-Src) may be involved in regulating ErbB2 biological activity. The major autophosphorylation sites in ErbB2 are Tyr1248 and Tyr1221/1222; phosphorylation of these sites couples ErbB2 to the Ras-Raf-MAP kinase signal transduction pathway (1,5).

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: The receptor-interacting protein (RIP) family of serine-threonine kinases (RIP, RIP2, RIP3, and RIP4) are important regulators of cellular stress that trigger pro-survival and inflammatory responses through the activation of NF-κB, as well as pro-apoptotic pathways (1). In addition to the kinase domain, RIP contains a death domain responsible for interaction with the death domain receptor Fas and recruitment to TNF-R1 through interaction with TRADD (2,3). RIP-deficient cells show a failure in TNF-mediated NF-κB activation, making the cells more sensitive to apoptosis (4,5). RIP also interacts with TNF-receptor-associated factors (TRAFs) and can recruit IKKs to the TNF-R1 signaling complex via interaction with NEMO, leading to IκB phosphorylation and degradation (6,7). Overexpression of RIP induces both NF-κB activation and apoptosis (2,3). Caspase-8-dependent cleavage of the RIP death domain can trigger the apoptotic activity of RIP (8).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: The vaccinia-related kinase (VRK) proteins are a new group of Ser/Thr kinases in the human kinome. This mammalian kinase family comprises three members, VRK1, VRK2, and VRK3 (1-3). The VRK1 has autophosphorylation activity and phosphorylates several transcription factors, including p53 (4), ATF2 (5), and c-Jun (6). VRK2 is associated with the endoplasmic reticulum (7). VRK3 suppresses Erk activity through direct interaction and activation of the MAP kinase phosphatase VHR (8). Further functional and structural analysis of VRK proteins will elucidate important new aspects of cell regulation.

$469
Reagents for 4 x 96 well plates
1 Kit
CST's PathScan® Total p53 Sandwich ELISA Antibody Pair is offered as an economical alternative to our PathScan® Total p53 Sandwich ELISA Kit #7370. Capture and Detection antibodies (100X stocks) and HRP-conjugated secondary antibody (1000X stock) are supplied. Sufficient reagents are supplied for 4 x 96 well ELISAs. The p53 Capture Antibody is coated in PBS overnight in a 96 well microplate. After blocking, cell lysates are added followed by a p53 Detection Antibody and anti-Mouse IgG, HRP conjugated antibody. HRP substrate, TMB, is added for color development. The magnitude of the absorbance for this developed color is proportional to the quantity of total p53 protein.Antibodies in kit are custom formulations specific to kit.
REACTIVITY
Human

Background: The p53 tumor suppressor protein plays a major role in cellular response to DNA damage and other genomic aberrations. Activation of p53 can lead to either cell cycle arrest and DNA repair or apoptosis (1). p53 is phosphorylated at multiple sites in vivo and by several different protein kinases in vitro (2,3). DNA damage induces phosphorylation of p53 at Ser15 and Ser20 and leads to a reduced interaction between p53 and its negative regulator, the oncoprotein MDM2 (4). MDM2 inhibits p53 accumulation by targeting it for ubiquitination and proteasomal degradation (5,6). p53 can be phosphorylated by ATM, ATR, and DNA-PK at Ser15 and Ser37. Phosphorylation impairs the ability of MDM2 to bind p53, promoting both the accumulation and activation of p53 in response to DNA damage (4,7). Chk2 and Chk1 can phosphorylate p53 at Ser20, enhancing its tetramerization, stability, and activity (8,9). p53 is phosphorylated at Ser392 in vivo (10,11) and by CAK in vitro (11). Phosphorylation of p53 at Ser392 is increased in human tumors (12) and has been reported to influence the growth suppressor function, DNA binding, and transcriptional activation of p53 (10,13,14). p53 is phosphorylated at Ser6 and Ser9 by CK1δ and CK1ε both in vitro and in vivo (13,15). Phosphorylation of p53 at Ser46 regulates the ability of p53 to induce apoptosis (16). Acetylation of p53 is mediated by p300 and CBP acetyltransferases. Inhibition of deacetylation suppressing MDM2 from recruiting HDAC1 complex by p19 (ARF) stabilizes p53. Acetylation appears to play a positive role in the accumulation of p53 protein in stress response (17). Following DNA damage, human p53 becomes acetylated at Lys382 (Lys379 in mouse) in vivo to enhance p53-DNA binding (18). Deacetylation of p53 occurs through interaction with the SIRT1 protein, a deacetylase that may be involved in cellular aging and the DNA damage response (19).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: Special AT-rich binding protein 1 (SATB1) functions as both a global chromatin organizer and a gene-specific transcription factor (1). SATB1 cooperates with promyelocytic leukemia protein (PML) to regulate global chromatin architecture by organizing chromatin into distinct loops via periodic anchoring of matrix attachment regions (MARs) in DNA to the nuclear matrix (1-3). In addition, SATB1 recruits multiple chromatin-remodeling proteins that contribute to specific gene activation and repression, including the chromatin remodeling enzymes ACF and ISWI, the histone deacetylase HDAC1, and the histone acetyltransferases PCAF and p300/CBP (4-6). Phosphorylation of SATB1 on Ser185 by protein kinase C regulates its interaction with HDAC1 and PCAF. While unphosphorylated SATB1 binds to PCAF, phosphorylated SATB1 preferentially binds to HDAC1 (6). Acetylation of SATB1 on Lys136 by PCAF impairs its DNA binding activity, thereby removing SATB1 from gene promoters (6). SATB1 is expressed predominantly in thymocytes and is involved in gene regulation during T cell activation (1). SATB1 is also expressed in metastatic breast cancer cells and is a potential prognostic marker and therapeutic target for metastatic breast cancer (7). In a mouse model system, RNAi-mediated knockdown of SATB1 reversed tumorigenesis by inhibiting tumor growth and metastasis, while ectopic expression of SATB1 in non-metastatic breast cancer cells produced invasive tumors.

Molecular Weight:560.64 g/mol

Background: Geldanamycin (GA) is a naturally existing HSP90 inhibitor that belongs to the benzoquinone ansamycin family. GA binds to the amino terminal ATP-binding pocket of HSP90 and inhibits ATP binding and hydrolysis. HSP90 is a chaperone interacting with a wide variety of important target proteins for cell signaling and regulation during tumorgenesis (1,2). The binding of GA to HSP90 interferes with HSP-mediated target protein folding, leading to target aggregation and degradation (1-3). GA and its synthetic derivatives show higher affinity to HSP90 in tumor cells as compared to normal tissues and constitute a class of protential antitumor drugs (2-3).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Macrophage inhibitory cytokine-1 (Mic-1), also termed GDF15 (1), PTGF-β (2), PLAB (3), PDF (4), and NAG-1 (5), is a divergent member of the transforming growth factor-β (TGF-β) superfamily (6). Like other family members, Mic-1 is synthesized as an inactive precursor that undergoes proteolytic processing involving removal of an N-terminal hydrophobic signal sequence followed by cleavage at a conserved RXXR site generating an active C-terminal domain that is secreted as a dimeric protein. Mic-1 is highly expressed in the placenta and is also dramatically increased by cellular stress, acute injury, inflammation, and cancer. In the brain, Mic-1 is found in the choroid plexus and is secreted into the cerebrospinal fluid (7). It is also a transcriptional target of the p53 tumor suppressor protein and may serve as a biomarker for p53 activity (8,9). During tumor progression, Mic-1 has various effects on apoptosis, differentiation, angiogenisis, and metastasis, and may also contribute to weight loss during cancer (10,11).

$489
96 assays
1 Kit
PathScan® Phospho-FGF Receptor 4 (panTyr) Sandwich ELISA Kit is a solid phase sandwich enzyme-linked immunosorbent assay (ELISA) that detects endogenous levels of tyrosine-phosphorylated FGR receptor 4 protein. An FGF receptor 4 rabbit mAb has been coated onto the microwells. After incubation with cell lysates, FGF receptor 4 protein (phospho and nonphospho) is captured by the coated antibody. Following extensive washing, a phospho-tyrosine mouse detection mAb is added to detect captured phospho-FGF receptor 4 protein. Anti-mouse IgG, HRP-linked antibody is then used to recognize the bound detection antibody. HRP substrate, TMB, is added to develop color. The magnitude of optical density for this developed color is proportional to the quantity of FGF Receptor 4 protein phosphorylated on tyrosine residues.Antibodies in the kit are custom formulations specific to kit.
REACTIVITY
Human

Background: Fibroblast growth factors (FGFs) produce mitogenic and angiogenic effects in target cells by signaling through cell surface receptor tyrosine kinases. There are four members of the FGF receptor family: FGFR1 (flg), FGFR2 (bek, KGFR), FGFR3, and FGFR4. Each receptor contains an extracellular ligand binding domain, a transmembrane domain, and a cytoplasmic kinase domain (1). Following ligand binding and dimerization, the receptors are phosphorylated at specific tyrosine residues (2). Seven tyrosine residues in the cytoplasmic tail of FGFR1 can be phosphorylated: Tyr463, 583, 585, 653, 654, 730, and 766. Tyr653 and Tyr654 are important for catalytic activity of activated FGFR and are essential for signaling (3). The other phosphorylated tyrosine residues may provide docking sites for downstream signaling components such as Crk and PLCγ (4,5).

$305
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to phycoerythrin (PE) 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 Brachyury (D2Z3J) Rabbit mAb #81694.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry

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).

$348
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. This antibody is expected to exhibit the same species cross-reactivity as the unconjugated Jagged1 (D4Y1R) Rabbit mAb #70109.
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse

Application Methods: Flow Cytometry

Background: Notch signaling is activated upon engagement of the Notch receptor with its ligands, the DSL (Delta, Serrate, Lag2) proteins of single-pass type I membrane proteins. The DSL proteins contain multiple EGF-like repeats and a DSL domain that is required for binding to Notch (1,2). Five DSL proteins have been identified in mammals: Jagged1, Jagged2, Delta-like (DLL) 1, 3 and 4 (3). Ligand binding to the Notch receptor results in two sequential proteolytic cleavages of the receptor by the ADAM protease and the γ-secretase complex. The intracellular domain of Notch is released and then translocates to the nucleus where it activates transcription. Notch ligands may also be processed in a way similar to Notch, suggesting a bi-directional signaling through receptor-ligand interactions (4-6).

$348
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 488 fluorescent dye and tested in-house for direct immunofluorescent analysis in human cells. This antibody is expected to exhibit the same species cross-reactivity as the unconjugated N-Cadherin (D4R1H) XP® Rabbit mAb #13116.
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Immunofluorescence (Immunocytochemistry)

Background: Cadherins are a superfamily of transmembrane glycoproteins that contain cadherin repeats of approximately 100 residues in their extracellular domain. Cadherins mediate calcium-dependent cell-cell adhesion and play critical roles in normal tissue development (1). The classic cadherin subfamily includes N-, P-, R-, B-, and E-cadherins, as well as about ten other members that are found in adherens junctions, a cellular structure near the apical surface of polarized epithelial cells. The cytoplasmic domain of classical cadherins interacts with β-catenin, γ-catenin (also called plakoglobin), and p120 catenin. β-catenin and γ-catenin associate with α-catenin, which links the cadherin-catenin complex to the actin cytoskeleton (1,2). While β- and γ-catenin play structural roles in the junctional complex, p120 regulates cadherin adhesive activity and trafficking (1-4). Investigators consider E-cadherin an active suppressor of invasion and growth of many epithelial cancers (1-3). Research studies indicate that cancer cells have upregulated N-cadherin in addition to loss of E-cadherin. This change in cadherin expression is called the "cadherin switch." N-cadherin cooperates with the FGF receptor, leading to overexpression of MMP-9 and cellular invasion (3). Research studies have shown that in endothelial cells, VE-cadherin signaling, expression, and localization correlate with vascular permeability and tumor angiogenesis (5,6). Investigators have also demonstrated that expression of P-cadherin, which is normally present in epithelial cells, is also altered in ovarian and other human cancers (7,8).

$348
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. This antibody is expected to exhibit the same species cross-reactivity as the unconjugated RCAS1 (D2B6N) XP® Rabbit mAb #12290.
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Flow Cytometry

Background: Receptor binding cancer antigen expressed on SiSo cells (RCAS1) is also known as estrogen receptor-binding fragment-associated gene 9 (EBAG9). Originally identified as an estrogen-inducible gene (1), RCAS1 was recently found to play a novel role in the adaptive immune response by negatively regulating the cytolytic activity of cytotoxic T lymphocytes (CTLs) (2). RCAS1 is conserved in phylogeny and is ubiquitously expressed in most human tissues and cells (3,4). There is evidence that tissue expression of RCAS1 is increased in a variety of malignancies, including cancers of the gastrointestinal tract, liver, lung, breast, ovary, endometrium, and cervix. Research studies have shown that levels of RCAS1 tissue expression are negatively correlated with the prognosis of patients harboring the aforementioned malignancies (4). It is also noteworthy that research studies have detected elevated levels of RCAS1 in the sera of cancer patients (4). Initial studies indicated that RCAS1 was secreted from cancer cells and functioned as a ligand for a putative receptor expressed on NK cells, as well as T and B lymphocytes, inducing their apoptosis, which enabled cancer cells to evade immune surveillance (5,6). Subsequent studies have identified RCAS1 as a type III transmembrane Golgi protein with the ability to regulate vesicle formation, secretion, and protein glycosylation (2,7-9). Indeed, it has been shown that RCAS1 overexpression negatively regulates the cytolytic function of CTLs by negatively regulating protein trafficking from the trans-Golgi to secretory lysosomes (2). Furthermore, RCAS1 overexpression delays vesicle transport from the ER to Golgi and causes components of the ER quality control and glycosylation machinery to mislocalize. As a consequence, RCAS1 induces the deposition of tumor-associated glycan antigens on the cell surface, which are thought to contribute to tumor pathogenesis through the mediation of adhesion, invasion, and metastasis (8,9).

$348
100 µl
This Cell Signaling Technology antibody is conjugated to the carbohydrate groups of horseradish peroxidase (HRP) via its amine groups. The HRP conjugated antibody is expected to exhibit the same species cross-reactivity as the unconjugated T7-Tag (D9E1X) XP® Rabbit mAb #13246.
APPLICATIONS
REACTIVITY
All Species Expected

Application Methods: Western Blotting

Background: Epitope tags are useful for the labeling and detection of proteins using immunoblotting, immunoprecipitation, and immunostaining techniques. Because of their small size, they are unlikely to affect the tagged protein’s biochemical properties.

$303
100 µl
APPLICATIONS
REACTIVITY
All Species Expected

Application Methods: Western Blotting

$345
100 µg
Neutralizing antibodies can be used to inhibit normal biological function through their binding to biological molecules. These reagents can be used to determine the effects that a particular molecule has in biological systems. Human IL-17A Neutralizing (D13C2) Rabbit mAb has been shown to neutralize the production of IL-6 from human dermal fibroblast cells in vitro with an ND50 in the range of 8-50 ng/ml.
REACTIVITY
Human
$262
3 nmol
300 µl
SignalSilence® hnRNP A1 siRNA I from Cell Signaling Technology (CST) allows the researcher to specifically inhibit hnRNP A1 expression using RNA interference, a method whereby gene expression can be selectively silenced through the delivery of double stranded RNA molecules into the cell. All SignalSilence® siRNA products from CST are rigorously tested in-house and have been shown to reduce target protein expression by western analysis.
REACTIVITY
Human

Background: Heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is a member of the hnRNP A/B family of related RNA binding proteins that bind pre-mRNA and are involved in the processing, metabolism, and transport of nuclear pre-mRNA transcripts (1). hnRNP A1 regulates the alternative splicing of c-Src and c-H-Ras (2,3) and modifies initiation of translation of the fibroblast growth factor 2 mRNA (4). hnRNP A1 expression level is elevated in many cancers; knockdown of hnRNP A1 leads to apoptosis in various cancer cells (5). Although predominantly nuclear, hnRNP A1 is continually transported from the nucleus to the cytoplasm where it disassociates from mRNA and is rapidly re-imported into the nucleus (6,7). hnRNP A1 binds to cis-acting repressive sequences (CRS) of HIV-1 to influence HIV-1 production (8,9). HIV-1 enhances hnRNP A1 expression and promotes the relocalization of hnRNP A1 to the cytoplasm (10).

$364
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to phycoerythrin (PE) and tested in-house for direct flow cytometry analysis in mouse cells. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated Phospho-GSK-3β (Ser9) (D85E12) XP® Rabbit mAb #5558.
APPLICATIONS
REACTIVITY
Hamster, Human, Mouse, Rat

Application Methods: Flow Cytometry

Background: Glycogen synthase kinase-3 (GSK-3) was initially identified as an enzyme that regulates glycogen synthesis in response to insulin (1). GSK-3 is a ubiquitously expressed serine/threonine protein kinase that phosphorylates and inactivates glycogen synthase. GSK-3 is a critical downstream element of the PI3K/Akt cell survival pathway whose activity can be inhibited by Akt-mediated phosphorylation at Ser21 of GSK-3α and Ser9 of GSK-3β (2,3). GSK-3 has been implicated in the regulation of cell fate in Dictyostelium and is a component of the Wnt signaling pathway required for Drosophila, Xenopus, and mammalian development (4). GSK-3 has been shown to regulate cyclin D1 proteolysis and subcellular localization (5).

$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: In response to genomic stress, the ATR interacting protein (ATRIP) binds and is phosphorylated by the DNA damage-and checkpoint-activated kinase ATR (ataxia-telangiectasia mutated and rad3-related). Both ATR and ATRIP are integral for checkpoint signaling and are critical in the DNA repair response (1-3). Direct interaction between ATRIP and replication protein A (RPA) at RPA-coated, single-stranded DNA results in the recruitment of phosphorylated ATR/ATRIP to stalled replication forks and sites of DNA damage (3). ATR/ATRIP coordinate DNA repair and cell cycle progression in conjunction with key regulatory proteins, such as Rad17 and the 9-1-1 complex (4). ATR associated with ATRIP can also be stimulated by topoisomerase II binding protein (TOPBP1), suggesting that ATRIP may regulate both ATR localization and activity (5).