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Product listing: CD44 (IM7) Rat mAb (PE-Cy7® Conjugate), UniProt ID P16070 #43675 to Arrestin 1/S-Arrestin Antibody, UniProt ID P10523 #11828

$229
100 µg
This Cell Signaling Technology antibody is conjugated to PE-Cy7® and tested in-house for direct flow cytometric analysis in human and mouse cells.
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Flow Cytometry

Background: CD44 is a type I transmembrane glycoprotein that mediates cell-cell and cell-matrix interaction through its affinity for hyaluronic acid (HA) and possibly through other parts of the extracellular matrix (ECM). CD44 is highly polymorphic, possesses a number of alternative splice variants and undergoes extensive post-translational modifications (1,2). Increased surface levels of CD44 are characteristic of T cell activation, and expression of the protein is upregulated during the inflammatory response. Research studies have shown that interactions between CD44 and HER2 are linked to an increase in ovarian carcinoma cell growth (1-3). CD44 interacts with ezrin, radixin and moesin (ERM), linking the actin cytoskeleton to the plasma membrane and the ECM (4-6). CD44 is constitutively phosphorylated at Ser325 in resting cells. Activation of PKC results in phosphorylation of Ser291, dephosphorylation of Ser325, disassociation of ezrin from CD44, and directional motility (4).

$269
100 µl
APPLICATIONS
REACTIVITY
Human

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

Background: Macrophage-colony stimulating factor (M-CSF, CSF-1) receptor is an integral membrane tyrosine kinase encoded by the c-fms proto-oncogene. M-CSF receptor is expressed in monocytes (macrophages and their progenitors) and drives growth and development of this blood cell lineage. (1-3). Binding of M-CSF to its receptor induces receptor dimerization, activation, and autophosphorylation of cytoplasmic tyrosine residues used as docking sites for SH2-containing signaling proteins (4). There are at least five major tyrosine autophosphorylation sites. Tyr723 (Tyr721 in mouse) is located in the kinase insert (KI) region. Phosphorylated Tyr723 binds the p85 subunit of PI3 kinase as well as PLCγ2 (5). Phosphorylation of Tyr809 provides a docking site for Shc (5). Overactivation of this receptor can lead to a malignant phenotype in various cell systems (6). The activated M-CSF receptor has been shown to be a predictor of poor outcome in advanced epithelial ovarian carcinoma (7) and breast cancer (8).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: MIF (macrophage migration inhibitory factor) is a pleiotropic cytokine that stimulates pro-inflammatory, chemotactic, and growth responses in cells (1). MIF binds its cognate receptor (a CD74/CD44 complex) to activate multiple signaling pathways such as Src, ERK, MAPK, Akt, and suppress p53-induced apoptosis (2). The interaction of MIF with non-cognate chemokine receptors CXCR2 and CXCR4 promotes chemotaxis that enables recruitment of monocytes/neutrophils and T cells (3). During an innate immune response, MIF has been shown to repress the inhibitory effects of glucocorticoids on macrophages and T cells, thus promoting host inflammation and immunity (4). MIF may also play roles in the progression of other disease processes, including cancer cell proliferation and metastasis, and angiogenesis (5), atherosclerotic plaque formation following myocardial ischemia (6), and autoimmune pathogenesis (7). MIF has thus been proposed as a promising therapeutic drug target for multiple indications.

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: Cystatin C (cystatin-3, CST3) belongs to the cystatin type 2 superfamily of cysteine peptidase inhibitors (1). The 146 amino acid cystatin C precursor protein contains a 26 residue, amino-terminal secretory signal sequence. The mature 120 amino acid cystatin C protein contains two disulfide bridges (2,3). Cystatin C is secreted in body fluids and is a marker of kidney (4) and cardiovascular (5) dysfunction. Research studies report of changes in cystatin C levels in the cerebral spinal fluid as well as in specific neuronal cell populations in a number of neurodegenerative diseases (6-8). Interestingly, experimental evidence suggests that cystatin C has protective effects against neurodegeneration, such as inhibition of amyloid-β oligomerization and fibril formation (9,10), induction of autophagy (11), induction of neurogenesis (12), and inhibition of cysteine proteases whose activity has been associated with several neurodegenerative diseases (13).

$263
100 tests
500 µl
This Cell Signaling Technology antibody is conjugated to PerCP-Cy5.5® and tested in-house for direct flow cytometry analysis in human cells.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry

Background: Cluster of Differentiation 8 (CD8) is a disulphide-linked heterodimer consisting of the unrelated α and β subunits. Each subunit is a glycoprotein composed of a single extracellular Ig-like domain, a polypeptide linker, a transmembrane part and a short cytoplasmic tail. On T cells, CD8 is the coreceptor for the T cell receptor (TCR), and these two distinct structures recognize the Antigen–Major Histocompatibility Complex (MHC). Specifically, the Ig-like domain of CD8α interacts with the α3-domain of the MHC class I molecule. CD8 ensures specificity of the TCR–antigen interaction, prolongs the contact between the T cell and the antigen presenting cell, and the α chain recruits the tyrosine kinase Lck, which is essential for T cell activation (1).

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

Application Methods: Immunofluorescence (Immunocytochemistry), Western Blotting

Background: A variety of factors contribute to the initiation of translation. Eukaryotic translation initiation factor 4H (eIF4H) was purified to near homogeneity from rabbit reticulocyte lysate and shown to stimulate translation in an assay deficient in eIF4F and eIF4B (1). eIF4H induces the RNA-dependent ATP hydrolysis catalyzed by the initiation factors eIF4A and eIF4B (1,2). eIF4H was further shown to stimulate the initial rate and extent of eIF4A-mediated mRNA secondary structure unwinding (3). Interaction between eIF4H and the herpes simplex virus shutoff protein (Vhs) appears to be important for Vhs-mediated degradation of mRNA (4). Deletion of a large region of chromosome 7, including the corresponding eIF4H gene, results in Williams-Beuren Syndrome (WBS), an autosomal dominant disorder that can present with cardiovascular problems, mental retardation and distinctive facial features (5).

$262
50-100 transfections
300 µl
SignalSilence® Chk1 siRNA from Cell Signaling Technology allows the researcher to specifically inhibit Chk1 expression using RNA interference, a method in which 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 protein expression in specified cell lines.
REACTIVITY
Human, Monkey

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).

$262
3 nmol
300 µl
SignalSilence® CREB siRNA from Cell Signaling Technology (CST) allows the researcher to specifically inhibit CREB 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: CREB is a bZIP transcription factor that activates target genes through cAMP response elements. CREB is able to mediate signals from numerous physiological stimuli, resulting in regulation of a broad array of cellular responses. While CREB is expressed in numerous tissues, it plays a large regulatory role in the nervous system. CREB is believed to play a key role in promoting neuronal survival, precursor proliferation, neurite outgrowth, and neuronal differentiation in certain neuronal populations (1-3). Additionally, CREB signaling is involved in learning and memory in several organisms (4-6). CREB is able to selectively activate numerous downstream genes through interactions with different dimerization partners. CREB is activated by phosphorylation at Ser133 by various signaling pathways including Erk, Ca2+, and stress signaling. Some of the kinases involved in phosphorylating CREB at Ser133 are p90RSK, MSK, CaMKIV, and MAPKAPK-2 (7-9).

$262
50-100 transfections
300 µl
SignalSilence® GSK-3α siRNA I from Cell Signaling Technology allows the researcher to specifically inhibit GSK-3α expression using RNA interference, a method in which 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 protein expression in specified cell lines.
REACTIVITY
Human, Monkey

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).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: CD7 is a type-I transmembrane glycoprotein belonging to the immunoglobulin superfamily. CD7 is one of the earliest surface markers to be expressed on the surface of developing T cells and its expression is maintained throughout maturation of multiple T cell subsets and NK cells (1-3). Engagement of CD7 through binding its ligand, SECTM1, has been shown to promote tyrosine phosphorylation of its cytoplasmic domain, recruitment of PI3K, and delivery of costimulatory signals for T cell activation (4-6). While CD7 is expressed on normal T cells, it is also highly expressed in a variety of T cell malignancies, which has poised it as a potential target of immunotherapy (7-9).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunofluorescence (Immunocytochemistry), Western Blotting

Background: LIN28A and LIN28B are conserved, developmentally regulated RNA binding proteins that inhibit the processing and maturation of the let-7 family of miRNAs (1,2). The let-7 miRNAs have been implicated in repression of oncogenes such as Ras, Myc, and HMGA2 (3). It has recently been shown that upregulation of LIN28A and LIN28B in primary human tumors and human cancer cell lines is correlated with downregulation of let-7 miRNAs (4). LIN28 genes are reported to be involved in primordial germ cell development and germ cell malignancy (5). In addition, allelic variation in LIN28B is associated with regulating the timing of puberty in humans (6). Overexpression of LIN28A, in conjunction with Oct-4, Sox2, and Nanog, can reprogram human fibroblasts to pluripotent, ES-like cells (7).

$262
3 nmol
300 µl
SignalSilence® Cyclin D1 siRNA II (Mouse Specific) from Cell Signaling Technology (CST) allows the researcher to specifically inhibit Cyclin D1 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
Mouse

Background: Activity of the cyclin-dependent kinases CDK4 and CDK6 is regulated by T-loop phosphorylation, by the abundance of their cyclin partners (the D-type cyclins), and by association with CDK inhibitors of the Cip/Kip or INK family of proteins (1). The inactive ternary complex of cyclin D/CDK4 and p27 Kip1 requires extracellular mitogenic stimuli for the release and degradation of p27 concomitant with a rise in cyclin D levels to affect progression through the restriction point and Rb-dependent entry into S-phase (2). The active complex of cyclin D/CDK4 targets the retinoblastoma protein for phosphorylation, allowing the release of E2F transcription factors that activate G1/S-phase gene expression (3). Levels of cyclin D protein drop upon withdrawal of growth factors through downregulation of protein expression and phosphorylation-dependent degradation (4).

$305
100 tests
500 µl
This Cell Signaling Technology antibody is conjugated to PE-Cy7® and tested in-house for direct flow cytometry analysis in human cells.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry

Background: Cluster of Differentiation 4 (CD4) is a glycoprotein composed of an amino-terminal extracellular domain (four domains: D1-D4 with Ig-like structures), a transmembrane part and a short cytoplasmic tail. CD4 is expressed on the surface of T helper cells, regulatory T cells, monocytes, macrophages and dendritic cells, and plays an important role in the development and activation of T cells. On T cells, CD4 is the co-receptor for the T cell receptor (TCR), and these two distinct structures recognize the Antigen–Major Histocompatibility Complex (MHC). Specifically, the D1 domain of CD4 interacts with the β2-domain of the MHC class II molecule. CD4 ensures specificity of the TCR–antigen interaction, prolongs the contact between the T cell and the antigen presenting cell and recruits the tyrosine kinase Lck, which is essential for T cell activation (1).

$305
100 tests
500 µl
This Cell Signaling Technology antibody is conjugated to PE-Cy7® and tested in-house for direct flow cytometry analysis in human cells.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry

Background: Cluster of Differentiation 8 (CD8) is a disulphide-linked heterodimer consisting of the unrelated α and β subunits. Each subunit is a glycoprotein composed of a single extracellular Ig-like domain, a polypeptide linker, a transmembrane part and a short cytoplasmic tail. On T cells, CD8 is the coreceptor for the T cell receptor (TCR), and these two distinct structures recognize the Antigen–Major Histocompatibility Complex (MHC). Specifically, the Ig-like domain of CD8α interacts with the α3-domain of the MHC class I molecule. CD8 ensures specificity of the TCR–antigen interaction, prolongs the contact between the T cell and the antigen presenting cell, and the α chain recruits the tyrosine kinase Lck, which is essential for T cell activation (1).

$320
100 µg
This peptide is used to block Phospho-EGF Receptor (Tyr1068) Antibody #2234 reactivity.
APPLICATIONS

Application Methods: Immunohistochemistry (Paraffin), Western Blotting

Background: The epidermal growth factor (EGF) receptor is a transmembrane tyrosine kinase that belongs to the HER/ErbB protein family. Ligand binding results in receptor dimerization, autophosphorylation, activation of downstream signaling, internalization, and lysosomal degradation (1,2). Phosphorylation of EGF receptor (EGFR) at Tyr845 in the kinase domain is implicated in stabilizing the activation loop, maintaining the active state enzyme, and providing a binding surface for substrate proteins (3,4). c-Src is involved in phosphorylation of EGFR at Tyr845 (5). The SH2 domain of PLCγ binds at phospho-Tyr992, resulting in activation of PLCγ-mediated downstream signaling (6). Phosphorylation of EGFR at Tyr1045 creates a major docking site for the adaptor protein c-Cbl, leading to receptor ubiquitination and degradation following EGFR activation (7,8). The GRB2 adaptor protein binds activated EGFR at phospho-Tyr1068 (9). A pair of phosphorylated EGFR residues (Tyr1148 and Tyr1173) provide a docking site for the Shc scaffold protein, with both sites involved in MAP kinase signaling activation (2). Phosphorylation of EGFR at specific serine and threonine residues attenuates EGFR kinase activity. EGFR carboxy-terminal residues Ser1046 and Ser1047 are phosphorylated by CaM kinase II; mutation of either of these serines results in upregulated EGFR tyrosine autophosphorylation (10).

$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Reverse orientation c-erbA gene α (Rev-erbα, EAR-1, or NR1D1) is a widely expressed member of the orphan nuclear receptor family of proteins (1). Rev-erbα is highly expressed in adipose tissue, skeletal muscle, brain and liver, and regulates cellular proliferation and differentiation. Expression increases during differentiation in adipocytes and ectopic expression of Rev-erbα potentiates the adipocyte differentiation of 3T3-L1 cells (2). In addition, expression oscillates with circadian rhythm in liver cells and Rev-erbα regulates expression of BMAL1, ApoA-I and ApoC-III, all key regulators of circadian rhythm (3-7). Phosphorylation of Rev-erbα Ser55 and Ser59 by GSK-3β appears to stabilize Rev-erbα protein levels and is important for synchronizing and maintaining the circadian clock (8). Rev-erbα also regulates inflammation by targeting the NF-κB responsive genes IL-6 and COX-2 (9). Rev-erbα lacks the activation function 2 domain required for ligand-dependent activation of transcription by other members of the nuclear receptor family; thus it behaves as a constitutive repressor protein, recruiting the nuclear receptor co-repressor (N-CoR)/HDAC3 complex to target genes to repress transcription (10).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Immunoprecipitation, Western Blotting

Background: Signal transducing adaptor molecule 2 (STAM2) is a ubiquitously expressed STAM family adaptor protein and an integral component of the ESCRT-0 complex. Similar to STAM1, STAM2 possesses a single SH3 domain and an immunoreceptor tyrosine-based activation motif (ITAM). Following activation of multiple growth factor and cytokine cell surface receptors, the STAM2 protein undergoes tyrosine phosphorylation and potentiates mitogenic signals driven by these receptors (1,2). Research studies demonstrate that STAM2 is localized to complexes containing Eps15, Hrs, and STAM1 proteins on early endosome membranes. A tandem, amino-terminal VHS (Vps27/Hrs/STAM) domain and UIM (ubiquitin-interacting) motif within STAM2 facilitate STAM2 interaction with ubiquitinated cargo proteins, suggesting that this adaptor participates in the endosomal sorting of ubiquitinated proteins targeted for lysosomal degradation (3-6). Gene targeting studies have revealed an indispensible role for STAM2 in T-cell development (7).

$260
100 µl
APPLICATIONS
REACTIVITY
Mouse, Rat

Application Methods: Western Blotting

Background: AMPA- (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid), kainate-, and NMDA- (N-methyl-D-aspartate) receptors are the three main families of ionotropic glutamate-gated ion channels. AMPA receptors (AMPARs) are comprised of four subunits (GluR 1-4), which assemble as homo- or hetero-tetramers to mediate the majority of fast excitatory transmissions in the central nervous system. AMPARs are implicated in synapse formation, stabilization, and plasticity (1). In contrast to GluR 2-containing AMPARs, AMPARs that lack GluR 2 are permeable to calcium (2). Post-transcriptional modifications (alternative splicing, nuclear RNA editing) and post-translational modifications (glycosylation, phosphorylation) result in a very large number of permutations, fine-tuning the kinetic properties of AMPARs. Research studies have implicated activity changes in AMPARs in a variety of diseases including Alzheimer’s, amyotrophic lateral sclerosis (ALS), stroke, and epilepsy (1).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: The nuclear pore complex (NPC) is a multi-subunit protein channel that spans the nuclear envelope and is responsible for the nucleocytoplasmic trafficking of RNA, proteins, and ribonucleoproteins (1). The 88 kDa nucleoporin protein (NUP88) is located on the cytoplasmic side of the NPC and found to be a part of a subcomplex with the NUP214 NPC subunit (1-3). This NUP88/NUP214 subcomplex interacts with CRM-1/exportin-1 to play an important role in the export of proteins, including the 60S ribosomal particle from the nucleus (4,5). Research studies demonstrate elevated expression and cytoplasmic accumulation of NUP88, visible as granular dots, in ovarian, prostate, and breast cancers (6-9). Increased NUP88 levels correlate with higher tumor grade, suggesting that NUP88 may be a putative tumor marker (1,7).

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

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

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).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: ADP-ribosylation factor GTPase activating protein 1 (ARFGAP1) is a Golgi-localized protein that regulates vesicle formation and membrane trafficking (1). ARFGAP1 initiates cargo selection and COP1 vesicle formation by stimulating GTP hydrolysis of ADP-ribosylation factor ARF1 (2). This GTPase activating protein initiates vesicle transport by coupling vesicle formation with cargo sorting (3). ARFGAP1 plays an active role in the Golgi-to-ER retrograde, intra-Golgi, and trans-Golgi trafficking networks (1). Research studies indicate that ARFGAP1 can act as a GTPase activating protein for LRRK2, a large multifunction protein whose genetic mutations are associated with Parkinson’s disease (4). ARFGAP1 regulates GTPase activity and promotes the kinase activity of LRRK2, which suggests some potential as a promising target for study of LRRK2 mediated neurodegeneration (4).

$320
100 µg
This peptide is used to specifically block Phospho-p38 MAPK (Thr180/Tyr182) (12F8) Rabbit mAb #4631 reactivity.
APPLICATIONS

Application Methods: Immunohistochemistry (Paraffin), Western Blotting

Background: p38 MAP kinase (MAPK), also called RK (1) or CSBP (2), is the mammalian orthologue of the yeast HOG kinase that participates in a signaling cascade controlling cellular responses to cytokines and stress (1-4). Four isoforms of p38 MAPK, p38α, β, γ (also known as Erk6 or SAPK3), and δ (also known as SAPK4) have been identified. Similar to the SAPK/JNK pathway, p38 MAPK is activated by a variety of cellular stresses including osmotic shock, inflammatory cytokines, lipopolysaccharide (LPS), UV light, and growth factors (1-5). MKK3, MKK6, and SEK activate p38 MAPK by phosphorylation at Thr180 and Tyr182. Activated p38 MAPK has been shown to phosphorylate and activate MAPKAP kinase 2 (3) and to phosphorylate the transcription factors ATF-2 (5), Max (6), and MEF2 (5-8). SB203580 (4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)-imidazole) is a selective inhibitor of p38 MAPK. This compound inhibits the activation of MAPKAPK-2 by p38 MAPK and subsequent phosphorylation of HSP27 (9). SB203580 inhibits p38 MAPK catalytic activity by binding to the ATP-binding pocket, but does not inhibit phosphorylation of p38 MAPK by upstream kinases (10).

$224
10 western blots
100 µl
Anti-Blue (2D2F11) Mouse mAb is conjugated to the carbohydrate groups of horseradish peroxidase (HRP) via its amine groups. This product has been optimized to detect proteins labeled with remazol blue.
APPLICATIONS

Application Methods: Western Blotting

Background: Chemiluminescence systems have emerged as the best all-around method for western blot detection. They eliminate the hazards associated with radioactive materials and toxic chromogenic substrates. The speed and sensitivity of these methods are unequalled by traditional alternatives, and because results are generated on film, it is possible to record and store data permanently. Blots detected with chemiluminescent methods are easily stripped for subsequent reprobing with additional antibodies. HRP-conjugated secondary antibodies are utilized in conjunction with specific chemiluminescent substrates to generate the light signal. HRP conjugates have a very high turnover rate, yielding good sensitivity with short reaction times.

$305
100 tests
500 µl
This Cell Signaling Technology antibody is conjugated to PE-Cy7® Conjugate and tested in-house for direct flow cytometric analysis in human cells.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry

Background: The protein phosphatase (PTP) receptor CD45 is a type I transmembrane protein comprised of a pair of intracellular tyrosine phosphatase domains and a variable extracellular domain generated by alternative splicing (1). The catalytic activity of CD45 is a function of the first phosphatase domain (D1) while the second phosphatase domain (D2) may interact with and stabilize the first domain, or recruit/bind substrates (2,3). CD45 interacts directly with antigen receptor complex proteins or activates Src family kinases involved in the regulation of T- and B-cell antigen receptor signaling (1). Specifically, CD45 dephosphorylates Src-family kinases Lck and Fyn at their conserved negative regulatory carboxy-terminal tyrosine residues and upregulates kinase activity. Conversely, studies indicate that CD45 can also inhibit Lck and Fyn by dephosphorylating their positive regulatory autophosphorylation site. CD45 appears to be both a positive and a negative regulator that conducts signals depending on specific stimuli and cell type (1). Human leukocytes including lymphocytes, eosinophils, monocytes, basophils, and neutrophils express CD45, while erythrocytes and platelets are negative for CD45 expression (4).

$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 Granzyme B (D2H2F) Rabbit mAb #17215.
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Flow Cytometry

Background: Granzymes are a family of serine proteases expressed by cytotoxic T lymphocytes and natural killer (NK) cells and are key components of immune responses to pathogens and transformed cells (1). Granzymes are synthesized as zymogens and are processed into mature enzymes by cleavage of a leader sequence. They are released by exocytosis in lysosome-like granules containing perforin, a membrane pore-forming protein. Granzyme B has the strongest apoptotic activity of all the granzymes as a result of its caspase-like ability to cleave substrates at aspartic acid residues thereby activating procaspases directly and cleaving downstream caspase substrates (2,3).

$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. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated IL-1β (D3U3E) Rabbit mAb #12703.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry

Background: Interleukin-1β (IL-1β), one of the major caspase-1 targets, is a multifunctional cytokine that is involved in a host of immune and proinflammatory responses (1). It is produced primarily by activated monocytes and macrophages. It signals through various adaptor proteins and kinases that lead to activation of numerous downstream targets (2-6). Human IL-1β is synthesized as a 31 kDa precursor. To gain activity, the precursor must be cleaved by caspase-1 between Asp116 and Ala117 to yield a 17 kDa mature form (7,8). Detection of the 17 kDa mature form of IL-1β is a good indicator of caspase-1 activity.

$262
3 nmol
300 µl
SignalSilence® HER3/ErbB3 siRNA II from Cell Signaling Technology (CST) allows the researcher to specifically inhibit HER3/ErbB3 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: 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
Mouse

Application Methods: Western Blotting

Background: The triggering receptor expressed on myeloid cells 2 (TREM2) protein is an innate immune receptor that is expressed on the cell surface of microglia, macrophages, osteoclasts, and immature dendritic cells (1). The TREM2 receptor is a single-pass type I membrane glycoprotein that consists of an extracellular immunoglobulin-like domain, a transmembrane domain, and a cytoplasmic tail. TREM2 interacts with the tyrosine kinase-binding protein DAP12 to form a receptor-signaling complex (2). The TREM2 protein plays a role in innate immunity and a rare functional variant (R47H) of TREM2 is associated with the late-onset risk of Alzheimer’s disease (1,3). Research studies using mouse models of Alzheimer’s disease indicate that deficiency and haploinsufficiency of TREM2 can lead to increased β-amyloid (Aβ) accumulation as a result of dysfunctional microglia response (4). These results agree with the distribution of TREM2 in human brain regions (e.g., white matter, the hippocampus, and neocortex) that are involved in Alzheimer's disease pathology (2). In addition, amyloid plaque formation induces expression of TREM2 and amyloid phagocytosis (5). Loss-of-function mutations in the corresponding TREM2 or DAP12 genes can result in Nasu-Hakola disease, a rare form of progressive presenile dementia that results from polycystic osseous lesions (6). TREM2 membrane shedding occurs by cleavage at the extracellular site between H157/S158 generating an N-terminal shedded fragment and a membrane bound C-terminal fragment (7, 8).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: Arrestin proteins function as negative regulators of G protein-coupled receptor (GPCR) signaling. Cognate ligand binding stimulates GPCR phosphorylation, which is followed by binding of arrestin to the phosphorylated GPCR and the eventual internalization of the receptor and desensitization of GPCR signaling (1). Four distinct mammalian arrestin proteins are known. Arrestin 1 (also known as S-arrestin) and arrestin 4 (X-arrestin) are localized to retinal rods and cones, respectively. Arrestin 2 (also known as β-arrestin 1) and arrestin 3 (β-arrestin 2) are ubiquitously expressed and bind to most GPCRs (2). β-arrestins function as adaptor and scaffold proteins and play important roles in other processes, such as recruiting c-Src family proteins to GPCRs in Erk activation pathways (3,4). β-arrestins are also involved in some receptor tyrosine kinase signaling pathways (5-8). Additional evidence suggests that β-arrestins translocate to the nucleus and help regulate transcription by binding transcriptional cofactors (9,10).