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Product listing: S100A9 (D5O6O) Rabbit mAb (IHC Formulated), UniProt ID P06702 #34425 to PiT1/SLC20A1 (D1Z4X) Rabbit mAb, UniProt ID Q8WUM9 #12765

$269
100 µl
APPLICATIONS
REACTIVITY
Human

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

Background: S100A8 and S100A9 are calcium-binding proteins that form a noncovalent heterodimer present in monocytes, neutrophils, macrophages, and some epithelial cells (1, 2). S100A8 and S100A9 are secreted by a tubulin-dependent mechanism during inflammatory conditions and have antimicrobial and chemotactic functions (3-5). Extracellular S100A8/S100A9 also induces an inflammatory response in endothelial cells, including induction of proinflammatory chemokines and adhesion molecules and increased vascular permeability (6). S100A8/S100A9 induces and recruits myeloid-derived suppressor cells (MDSC) in tumor-bearing mice (7). MDSC produce additional S100A8/S100A9 themselves, resulting in a positive feedback mechanism that sustains MDSC accumulation (7). S100A8/S100A9 is also highly expressed in psoriatic skin, where it directly upregulates transcription of complement protein C3, which contributes to disease (8). In addition, tumor-infiltrating myeloid cells induce expression of S100A8 and S100A9 in cancer cells, which increases invasiveness and metastasis (9).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: The NF-κB/Rel transcription factors are present in the cytosol in an inactive state, complexed with the inhibitory IκB proteins (1-3). Most agents that activate NF-κB do so through a common pathway based on phosphorylation-induced, proteasome-mediated degradation of IκB (3-7). The key regulatory step in this pathway involves activation of a high molecular weight IκB kinase (IKK) complex whose catalysis is generally carried out by three tightly associated IKK subunits. IKKα and IKKβ serve as the catalytic subunits of the kinase and IKKγ serves as the regulatory subunit (8,9). Activation of IKK depends upon phosphorylation at Ser177 and Ser181 in the activation loop of IKKβ (Ser176 and Ser180 in IKKα), which causes conformational changes, resulting in kinase activation (10-13).

$305
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 Stat3 (D3Z2G) Rabbit mAb #12640.
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Flow Cytometry

Background: The Stat3 transcription factor is an important signaling molecule for many cytokines and growth factor receptors (1) and is required for murine fetal development (2). Research studies have shown that Stat3 is constitutively activated in a number of human tumors (3,4) and possesses oncogenic potential (5) and anti-apoptotic activities (3). Stat3 is activated by phosphorylation at Tyr705, which induces dimerization, nuclear translocation, and DNA binding (6,7). Transcriptional activation seems to be regulated by phosphorylation at Ser727 through the MAPK or mTOR pathways (8,9). Stat3 isoform expression appears to reflect biological function as the relative expression levels of Stat3α (86 kDa) and Stat3β (79 kDa) depend on cell type, ligand exposure, or cell maturation stage (10). It is notable that Stat3β lacks the serine phosphorylation site within the carboxy-terminal transcriptional activation domain (8).

20 mM Citrate pH 3.0 (Sterile) is specifically formulated to be used as a buffer for reconstituting sterile cytokines or antibodies.
$327
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 647 fluorescent dye and tested in-house for direct flow cytometry and immunofluorescent analysis in human cells. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated Phospho-p53 (Ser15) (16G8) Mouse mAb #9286.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry

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).

This peptide is used to block Phospho-Stat1 (Tyr701) (58D6) Rabbit mAb #9167 reactivity.

Background: The Stat1 transcription factor is activated in response to a large number of ligands (1) and is essential for responsiveness to IFN-α and IFN-γ (2,3). Phosphorylation of Stat1 at Tyr701 induces Stat1 dimerization, nuclear translocation, and DNA binding (4). Stat1 protein exists as a pair of isoforms, Stat1α (91 kDa) and the splice variant Stat1β (84 kDa). In most cells, both isoforms are activated by IFN-α, but only Stat1α is activated by IFN-γ. The inappropriate activation of Stat1 occurs in many tumors (5). In addition to tyrosine phosphorylation, Stat1 is also phosphorylated at Ser727 through a p38 mitogen-activated protein kinase (MAPK)-dependent pathway in response to IFN-α and other cellular stresses (6). Serine phosphorylation may be required for the maximal induction of Stat1-mediated gene activation.

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: Galectins are a family of β-galactose binding proteins that are characterized by their affinity for poly-N-acetyllactosamine-enriched glycoconjugates and their 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-1/LGALS1 has been shown to be expressed in a wide range of tissues and cell types. The level and pattern of expression of galectin-1 have been shown to change during development (8). In addition to a role in developmental processes, galectin-1 has been shown to be involved in central immune tolerance and may function in tumorigenesis by modulating the immune response to the tumor (9,10). Research studies have shown that galectin-1 expression is increased in several human cancers, suggesting a correlation with metastatic potential (10).

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

Application Methods: Immunoprecipitation, Western Blotting

Background: Checkpoint with forkhead and RING finger domains protein (CHFR) is an E3 ubiquitin-protein ligase that regulates cell cycle progression. In response to microtubule stress, CHFR delays the transition into mitosis by excluding cyclin B1 from the nucleus prior to chromosome condensation (1). Marked reduction of CHFR expression was detected in primary tumors and decreased CHFR expression was linked to promoter hypermethylation (1-4). Restoration of CHFR expression by treatment with the microtubule stress agent nocodazole and the methyltransferase inhibitor 5-aza-2'-deoxycytidine has been reported (4,5).

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

Application Methods: Immunoprecipitation, Western Blotting

Background: Nucleoporin 98 kDa (NUP98) is a component of the nuclear pore complex. It is expressed as three different precursors that undergo auto-cleavage to generate a common amino-terminal 98 kDa peptide (NUP98) and carboxy-terminal 6, 96 (NUP96) and 88 (p88) kDa peptides (1,2). NUP98 contains FG and GLFG repeat domains at its amino terminus and a RNA-binding domain in its carboxy terminus (3). The NUP98 gene is localized on chromosome 11p15.5, a region frequently rearranged in leukemias. To date, 15 fusion partners have been identified for NUP98 (4,5).

$489
96 assays
1 Kit
PathScan® Total Ezh2 Sandwich ELISA Kit is a solid phase sandwich enzyme-linked immunosorbent assay (ELISA) that detects endogenous levels of total Ezh2 protein. An Ezh2 specific antibody has been coated onto the microwells. After incubation with cell lysates, Ezh2 protein is captured by the coated antibody. Following extensive washing, an Ezh2 mouse mAb is added to detect the captured Ezh2 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 total Ezh2 protein.Antibodies in kit are custom formulations specific to kit.
REACTIVITY
Human, Monkey

Background: The polycomb group (PcG) proteins are involved in maintaining the silenced state of several developmentally regulated genes and contribute to the maintenance of cell identity, cell cycle regulation, and oncogenesis (1,2). Enhancer of zeste homolog 2 (Ezh2), a member of this large protein family, contains four conserved regions including domain I, domain II, and a cysteine-rich amino acid stretch that precedes the carboxy-terminal SET domain (3). The SET domain has been linked with histone methyltransferase (HMTase) activity. Moreover, mammalian Ezh2 is a member of a histone deacetylase complex that functions in gene silencing, acting at the level of chromatin structure (4). Ezh2 complexes methylate histone H3 at Lys9 and 27 in vitro, which is thought to be involved in targeting transcriptional regulators to specific loci (5). Ezh2 is deregulated in various tumor types, and its role, both as a primary effector and as a mediator of tumorigenesis, has become a subject of increased interest (6).

$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Hepatocyte nuclear factor 1α (HNF1α, also known as TCF1 or MODY3) is a transcription factor that plays a role in the tissue-specific regulation of liver gene expression (1). Research has shown that heterogeneous mutations of HNF1α are linked to maturity onset diabetes of the young (MODY) (2). Recent studies indicate that increased concentrations of free fatty acids can reduce the expression of FoxA2/HNF3β and HNF1α in pancreatic β-cells and lead to their nuclear exclusion, resulting in symptoms of several metabolic syndromes (3).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: Apolipoproteins are plasma lipoproteins that function as transporters of lipids and cholesterol in the circulatory system. Chylomicrons are a fundamental class of apolipoproteins containing very low-density lipoproteins (VLDL), intermediate-density lipoproteins (IDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL) (1,2).

$327
100 µl
This Cell Signaling Technology antibody is conjugated to biotin under optimal conditions. The biotinylated antibody is expected to exhibit the same species cross-reactivity as the unconjugated Phospho-Syk (Tyr525/526) (C87C1) Rabbit mAb #2710.
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Syk is a protein tyrosine kinase that plays an important role in intracellular signal transduction in hematopoietic cells (1-3). Syk interacts with immunoreceptor tyrosine-based activation motifs (ITAMs) located in the cytoplasmic domains of immune receptors (4). It couples the activated immunoreceptors to downstream signaling events that mediate diverse cellular responses, including proliferation, differentiation, and phagocytosis (4). There is also evidence of a role for Syk in nonimmune cells and investigators have indicated that Syk is a potential tumor suppressor in human breast carcinomas (5). Tyr323 is a negative regulatory phosphorylation site within the SH2-kinase linker region in Syk. Phosphorylation at Tyr323 provides a direct binding site for the TKB domain of Cbl (6,7). Tyr352 of Syk is involved in the association of PLCγ1 (8). Tyr525 and Tyr526 are located in the activation loop of the Syk kinase domain; phosphorylation at Tyr525/526 of human Syk (equivalent to Tyr519/520 of mouse Syk) is essential for Syk function (9).

$305
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 488 fluorescent dye and tested in-house for direct flow cytometry and immunofluorescent analysis in human cells.The antibody is expected to exhibit the same species cross-reactivity as the unconjugated Survivin (71G4B7) Rabbit mAb #2808.
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Flow Cytometry, Immunofluorescence (Immunocytochemistry)

Background: Survivin is a 16 kDa anti-apoptotic protein highly expressed during fetal development and cancer cell malignancy (1). Survivin binds and inhibits caspase-3, controlling the checkpoint in the G2/M-phase of the cell cycle by inhibiting apoptosis and promoting cell division (2,3). This regulatory process requires the phosphorylation of survivin at Thr34 by p34 cdc2 kinase (4). Gene targeting using a Thr34 phosphorylation-defective survivin mutant, as well as antisense survivin, have been shown to inhibit tumor growth (5,6).

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

Application Methods: Western Blotting

Background: The common beta-chain (beta-c) of the granulocyte macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3) and IL-5 receptors is the major signaling subunit of these receptors, coupling ligand binding to multiple biological activities (1-3). Tyrosine phosphorylation of cytokine receptor common beta-chain is one of the first events in GM-CSF, IL-3 and IL-5 receptor activation and in signaling initiation (4). Serine phosphorylation within the 14-3-3 binding sequence of the common beta-chain is also involved in GM-CSF, IL-3 and IL-5 receptor-specific functions (5,6).

$305
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 647 fluorescent dye and tested in-house for direct flow cytometry and immunofluorescent analysis in human cells. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated Oct-4A (C30A3) Rabbit mAb #2840.
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Flow Cytometry, Immunofluorescence (Immunocytochemistry)

Background: Oct-4 (POU5F1) is a transcription factor highly expressed in undifferentiated embryonic stem cells and embryonic germ cells (1). A network of key factors that includes Oct-4, Nanog, and Sox2 is necessary for the maintenance of pluripotent potential, and downregulation of Oct-4 has been shown to trigger cell differentiation (2,3). Research studies have demonstrated that Oct-4 is a useful germ cell tumor marker (4). Oct-4 exists as two splice variants, Oct-4A and Oct-4B (5). Recent studies have suggested that the Oct-4A isoform has the ability to confer and sustain pluripotency, while Oct-4B may exist in some somatic, non-pluripotent cells (6,7).

$260
100 µl
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.

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: The proprotein convertases (PCs) are enzymes that activate precursor proteins through proteolytic cleavage within the secretory pathway. PCs comprise several enzymes that are basic amino acid-specific proteinases (furin, PC1/3, PC2, PC4, PACE4, PC5/6, and PC7), as well as nonbasic amino acid convertases (S1P and PC9) (1). PCs have a common structure that includes an N-terminal signal peptide for secretory pathway targeting; a pro-domain that is thought to act as an intramolecular chaperone; a catalytic domain containing the active site; a P-domain that contributes to the overall folding of the enzyme by regulating stability, calcium-, and pH-dependence; and a C-terminal domain that interacts with the membrane (2). PCs act in a tissue- and substrate-specific fashion to generate an array of bioactive peptides and proteins from precursors, both in the brain and the periphery (3).

$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 PCNA (D3H8P) XP® Rabbit mAb #13110.
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Flow Cytometry, Immunofluorescence (Frozen), Immunofluorescence (Immunocytochemistry)

Background: Proliferating cell nuclear antigen (PCNA) is a member of the DNA sliding clamp family of proteins that assist in DNA replication (1). Crystal structure data suggests that a PCNA homotrimer ring can encircle and slide along the DNA double helix (2). Multiple proteins involved in DNA replication, DNA repair, and cell cycle control bind to PCNA rather than directly associating with DNA, thus facilitating fast processing of DNA (reviewed in 3). PCNA protein expression is a well-accepted marker of proliferation.

$305
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 Sox9 (D8G9H) Rabbit mAb #82630.
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Flow Cytometry

Background: Sox9 is a transcription factor with an HMG-box DNA binding domain that has homology to the HMG domain of the mammalian testis-determining factor, SRY (1). Sox9 regulates several important processes during embryonic development including chondrogenesis, during which it contributes to skeletal formation and digit specification (2,3). Sox9 also coordinates with steroidogenic factor-1 to direct Sertoli cell-specific expression of anti-Mullerian hormone during embryogenesis, thereby contributing to male sex determination (4). In addition, Sox9 is reportedly involved in the maintenance of adult stem cell populations, including multipotent neural stem cells (5), hair follicle stem cells (6), and mammary stem cells (7). Recent interest has focused on the role of Sox9 in tumor biology. For example, research studies have shown that Sox9 expression in lung adenocarcinoma induces a mesenchymal phenotype in tumor cells (8). Other research studies have shown that YAP1 induced upregulation of Sox9 confers cancer stem cell like properties on esophageal cancer cells (9). Moreover, Sox9 expression has been linked with several other tumor types including ovarian, prostate, and pancreatic malignancies (10-12).

$260
100 µl
APPLICATIONS
REACTIVITY
Bovine, Dog, Hamster, Human, Monkey, Mouse, Pig, Rat

Application Methods: Western Blotting

Background: The 90 kDa ribosomal S6 kinases (RSK1-4) are a family of widely expressed Ser/Thr kinases characterized by two nonidentical, functional kinase domains (1) and a carboxy-terminal docking site for extracellular signal-regulated kinases (ERKs) (2). Several sites both within and outside of the RSK kinase domain, including Ser380, Thr359, Ser363, and Thr573, are important for kinase activation (3). RSK1-3 are activated via coordinated phosphorylation by MAPKs, autophosphorylation, and phosphoinositide-3-OH kinase (PI3K) in response to many growth factors, polypeptide hormones, and neurotransmitters (3).

$262
3 nmol
300 µl
SignalSilence® HSP27 siRNA II from Cell Signaling Technology (CST) allows the researcher to specifically inhibit HSP27 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 are rigorously tested in-house and have been shown to reduce target protein expression by western analysis.
REACTIVITY
Human

Background: Heat shock protein (HSP) 27 is one of the small HSPs that are constitutively expressed at different levels in various cell types and tissues. Like other small HSPs, HSP27 is regulated at both the transcriptional and posttranslational levels (1). In response to stress, the HSP27 expression increases several-fold to confer cellular resistance to the adverse environmental change. HSP27 is phosphorylated at Ser15, Ser78, and Ser82 by MAPKAPK-2 as a result of the activation of the p38 MAP kinase pathway (2,3). Phosphorylation of HSP27 causes a change in its tertiary structure, which shifts from large homotypic multimers to dimers and monomers (4). It has been shown that phosphorylation and increased concentration of HSP27 modulates actin polymerization and reorganization (5,6).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: GBP5 (guanylate binding protein 5) is one of seven interferon-inducible GTPases in humans that have recently been shown to be involved in host defense against intracellular pathogens (1,2). Specifically, in response to intracellular bacteria or cell wall components, GBP5 acts as a tetramer to facilitate assembly of the NLRP3 inflammasome, leading to caspase-1 activation (2,3). In addition, GBP5 enables activation of the AIM2 inflammasome by promoting lysis of intracellular bacteria and release of pathogenic double-stranded DNA (4).

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

Application Methods: Western Blotting

Background: Protein ubiquitination is an important posttranslational modification that regulates protein function and fate (1). Ubiquitin (Ub) can be conjugated to target proteins in either monomeric or polymeric forms. There are several different lysine residues within Ub that can be used as conjugation sites for poly-Ub chain formation. Different poly-Ub linkages mediate different functions of the target protein ranging from alterations in protein function to degradation (2). UBE2N/Ubc13 is a ubiquitin-E2-conjugating enzyme that catalyzes K63-linked poly-Ub chain formation (1,2). UBE2N forms a heterodimer with MMS2 or Uev1A to exert its E2 ligase function. The UBE2N/MMS2 and UBE2N/Uev1A heterodimers catalyze different modes of target protein ubiquitination to mediate various signaling pathways (3-5) including: DNA damage and recombination, p53 and check point control, the cell cycle (6-10), immunoreceptor signaling (11,12), and endocytosis (13). Most recently, UBE2N was shown to play an important role in inflammatory signaling by promoting K63-linked ubiquitination and activation of IKK downstream of the IL-1β receptor (14). Furthermore, interaction of UBE2N with the Triad1 E3 protein-ubiquitin ligase was shown to play an important role in myelopoiesis (15).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Fodrin (also named nonerythroid spectrin) is a universally expressed membrane-associated cytoskeletal protein consisting of alpha- and beta-subunits (1). This protein is important for maintaining normal membrane structure and supporting cell surface protein function (1). Alpha-fodrin is one of the primary targets cleaved by caspases during apoptosis. The full length 240 kDa protein can be cleaved at several sites within its sequence by activated caspases to yield amino-terminal 150 kDa, carboxy-terminal 120 kDa and 35 kDa major products (2-5). Cleavage of alpha-fodrin leads to membrane malfunction and cell shrinkage.

$262
3 nmol
300 µl
SignalSilence® Stat3 siRNA II from Cell Signaling Technology (CST) allows the researcher to specifically inhibit Stat3 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: The Stat3 transcription factor is an important signaling molecule for many cytokines and growth factor receptors (1) and is required for murine fetal development (2). Research studies have shown that Stat3 is constitutively activated in a number of human tumors (3,4) and possesses oncogenic potential (5) and anti-apoptotic activities (3). Stat3 is activated by phosphorylation at Tyr705, which induces dimerization, nuclear translocation, and DNA binding (6,7). Transcriptional activation seems to be regulated by phosphorylation at Ser727 through the MAPK or mTOR pathways (8,9). Stat3 isoform expression appears to reflect biological function as the relative expression levels of Stat3α (86 kDa) and Stat3β (79 kDa) depend on cell type, ligand exposure, or cell maturation stage (10). It is notable that Stat3β lacks the serine phosphorylation site within the carboxy-terminal transcriptional activation domain (8).

$327
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 Phospho-Stat6 (Tyr641) (D8S9Y) Rabbit mAb #56554.
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Flow Cytometry

Background: Upon activation by Janus kinases, Stat6 translocates to the nucleus where it regulates cytokine-induced gene expression. Stat6 is activated via phosphorylation at Tyr641 and is required for responsiveness to IL-4 and IL-13 (1-4). In addition, Stat6 is activated by IFN-α in B cells, where it forms transcriptionally active complexes with Stat2 and p48 (5,6). Protein phosphatase 2A is also involved in regulation of IL-4-mediated Stat6 signaling (7).

$122
20 µl
$303
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Immunoprecipitation, Western Blotting

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).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: Phosphate transporter 1 (PiT1/SLC20A1) is a sodium dependent phosphate (Pi) transporter that imports Pi into cells. PiT1 was initially identified as a receptor for retroviruses (1,2). It is widely expressed in various tissues where it plays a critical role in maintaining cellular Pi homeostasis (3,4). Phosphate transporter 1 is important in cell proliferation and tumor cell growth independent of PiT1 phosphate transport function (5). Researchers have found that PiT1 is involved in TNF-α induced apoptosis (6). Moreover, phosphate uptake via PiT1 is crucial for vascular calcification (7) and overexpression of PiT1 leads to soft tissue calcification in Werner syndrome patients (8). Additional research indicates that increased PiT1 expression is seen in calcific aortic valve disease (CAVD) tissues, and that PiT1 enhances apoptosis and mineralization by modifying Akt1 levels (9).