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Product listing: PDI (C81H6) Rabbit mAb (Alexa Fluor® 488 Conjugate), UniProt ID P07237 #5051 to Phospho-Stat1 (Tyr701) (58D6) Rabbit mAb (Biotinylated), UniProt ID P42224 #5375

$305
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. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated PDI (C81H6) Rabbit mAb #3501.
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Immunofluorescence (Immunocytochemistry)

Background: During their synthesis, secretory proteins translocate into the endoplasmic reticulum (ER) where they are post-translationally modified and properly folded. To reach their native conformation, many secretory proteins require the formation of intra- or inter-molecular disulfide bonds (1). This process is called oxidative protein folding. Protein disulfide isomerase (PDI) catalyzes the formation and isomerization of these disulfide bonds (2). Studies on mechanisms of oxidative folding suggest that molecular oxygen oxidizes the ER-protein Ero1, which in turn oxidizes PDI through disulfide exchange (3). This event is then followed by PDI-catalyzed disulfide bond formation in folding proteins (3).

$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: The Forkhead family of transcription factors is involved in tumorigenesis of rhabdomyosarcoma and acute leukemias (1-3). Within the family, three members (FoxO1, FoxO4, and FoxO3a) have sequence similarity to the nematode orthologue DAF-16, which mediates signaling via a pathway involving IGFR1, PI3K, and Akt (4-6). Active forkhead members act as tumor suppressors by promoting cell cycle arrest and apoptosis. Increased expression of any FoxO member results in the activation of the cell cycle inhibitor p27 Kip1. Forkhead transcription factors also play a part in TGF-β-mediated upregulation of p21 Cip1, a process negatively regulated through PI3K (7). Increased proliferation results when forkhead transcription factors are inactivated through phosphorylation by Akt at Thr24, Ser256, and Ser319, which results in nuclear export and inhibition of transcription factor activity (8). Forkhead transcription factors can also be inhibited by the deacetylase sirtuin (SirT1) (9).

$111
20 µl
$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: Cyclin H belongs to a conserved cyclin family that plays a critical role in the regulation of cell cycle dependent kinases (CDKs) necessary for cell cycle progression (1,2). In general, the activity of CDKs requires the binding of appropriate cyclins as well as phosphorylation driven by Cdk-activating kinase (CAK). Cyclin H is part of the CAK complex that includes the kinase CDK7, and an assembly factor p36/Mat1, which enhances binding between cyclin H and CDK7 and increases activity (3,4). CAK regulates progression through the cell cycle by activating cdc2, CDK2, and CDK4 kinases through phosphorylation of a critical threonine residue in the T-loop of the CDK-cyclin complexes (5,6). The CAK complex can exist either in its free form or in association with transcription factor IIH (TFIIH) which can affect its substrate specificity (7,8,9). When bound to TFIIH, CAK preferentially phosphorylates the carboxy-terminal domain of RNA polymerase II (9), providing a link between cell cycle control, transcriptional regulation, and DNA repair.

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: ApoAI (Apolipoprotein A1) is a major component of high density lipoprotein (HDL, the “good cholesterol”) in plasma. It is produced in the liver and small intestine. ApoA1 is a cofactor for lecithin cholesterolacyltransferase (LCAT) that is responsible for the formation of plasma cholesteryl esters and promotes cholesterol efflux from tissues to the liver for excretion. Defects in ApoA1 are associated with high density lipoprotein deficiency (HDLD) and systemic non-neuropathic amyloidosis (1-3).

$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 Cre Recombinase (D7L7L) Rabbit mAb #15036.
APPLICATIONS
REACTIVITY
All Species Expected

Application Methods: Flow Cytometry

Background: Cre recombinase is a bacteriophage-P1 enzyme required for maintenance of the phage genome as a monomeric plasmid in the lysogenic state (1,2). This enzyme mediates a site-specific recombination between two 34-base pair loxP sites. This reaction can be carried out in vitro, indicating that it does not require accessory factors (3). The Cre/Lox system has been used for a number of in vitro and in vivo applications including targeted gene deletions (4) and gene-specific humanized animal models (5). Resolution of the crystal structure of the Cre-Lox complex revealed that two Cre molecules interact with a single Lox site (6).

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

Application Methods: Western Blotting

Background: The 14-3-3 family of proteins plays a key regulatory role in signal transduction, checkpoint control, apoptotic and nutrient-sensing pathways (1,2). 14-3-3 proteins are highly conserved and ubiquitously expressed. There are at least seven isoforms, β, γ, ε, σ, ζ, τ, and η that have been identified in mammals. The initially described α and δ isoforms are confirmed to be phosphorylated forms of β and ζ, respectively (3). Through their amino-terminal α helical region, 14-3-3 proteins form homo- or heterodimers that interact with a wide variety of proteins: transcription factors, metabolic enzymes, cytoskeletal proteins, kinases, phosphatases, and other signaling molecules (3,4). The interaction of 14-3-3 proteins with their targets is primarily through a phospho-Ser/Thr motif. However, binding to divergent phospho-Ser/Thr motifs, as well as phosphorylation independent interactions has been observed (4). 14-3-3 binding masks specific sequences of the target protein, and therefore, modulates target protein localization, phosphorylation state, stability, and molecular interactions (1-4). 14-3-3 proteins may also induce target protein conformational changes that modify target protein function (4,5). Distinct temporal and spatial expression patterns of 14-3-3 isoforms have been observed in development and in acute response to extracellular signals and drugs, suggesting that 14-3-3 isoforms may perform different functions despite their sequence similarities (4). Several studies suggest that 14-3-3 isoforms are differentially regulated in cancer and neurological syndromes (2,3).

The Loading Control Antibody Sampler Kit provides an economical means to detect a variety of housekeeping proteins. The kit contains enough primary and secondary antibodies to perform two western blot experiments.
$270
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Flow Cytometry, Western Blotting

Background: Heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNP A2/B1) 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). Alternative splicing produces transcripts that encode two homologous hnRNP proteins, hnRNPA2 and hnRNPB1, from a single gene sequence (2). Studies demonstrate hnRNP A2/B1 splicing repression across multiple targets (3,4) and that both proteins can bind and protect telomere repeat sequences from DNase digestion (5,6). Altered expression of hnRNP B1 is seen in several forms of cancer, including squamous cell carcinoma, adenocarcinoma, and various forms of lung cancer (7). Over expression of hnRNP B1 may be associated with inhibition of DNA-PK activity and impaired DNA repair during early stages of cancer development (8). Autoantigens to hnRNP A2/B1 (termed RA33) are associated with rheumatoid arthritis, systemic lupus erythromatosus and mixed connective tissue disease (9-11).

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

Application Methods: Western Blotting

Background: Aldolase (fructose bisphosphate aldolase), a glycolytic enzyme, catalyzes the conversion of fructose 1, 6-bisphosphate to 3-phosphoglyceraldehyde. This ubiquitous enzyme is present as three different isozymes: aldolase A, aldolase B, and aldolase C. Research studies suggest that aldolase A expression potentially differentiates between nonneoplastic liver diseases and hepatocarcinoma (1). Furthermore, investigators have shown that changes in aldolase B gene expression levels have been observed in certain patients with this primary tumor (2,3).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Western Blotting

Background: AMP-activated protein kinase (AMPK) is highly conserved from yeast to plants and animals and plays a key role in the regulation of energy homeostasis (1). AMPK is a heterotrimeric complex composed of a catalytic α subunit and regulatory β and γ subunits, each of which is encoded by two or three distinct genes (α1, 2; β1, 2; γ1, 2, 3) (2). The kinase is activated by an elevated AMP/ATP ratio due to cellular and environmental stress, such as heat shock, hypoxia, and ischemia (1). The tumor suppressor LKB1, in association with accessory proteins STRAD and MO25, phosphorylates AMPKα at Thr172 in the activation loop, and this phosphorylation is required for AMPK activation (3-5). AMPKα is also phosphorylated at Thr258 and Ser485 (for α1; Ser491 for α2). The upstream kinase and the biological significance of these phosphorylation events have yet to be elucidated (6). The β1 subunit is post-translationally modified by myristoylation and multi-site phosphorylation including Ser24/25, Ser96, Ser101, Ser108, and Ser182 (6,7). Phosphorylation at Ser108 of the β1 subunit seems to be required for the activation of AMPK enzyme, while phosphorylation at Ser24/25 and Ser182 affects AMPK localization (7). Several mutations in AMPKγ subunits have been identified, most of which are located in the putative AMP/ATP binding sites (CBS or Bateman domains). Mutations at these sites lead to reduction of AMPK activity and cause glycogen accumulation in heart or skeletal muscle (1,2). Accumulating evidence indicates that AMPK not only regulates the metabolism of fatty acids and glycogen, but also modulates protein synthesis and cell growth through EF2 and TSC2/mTOR pathways, as well as blood flow via eNOS/nNOS (1).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Immunofluorescence (Immunocytochemistry), Western Blotting

Background: Phosphoinositide-3,4,5-triphosphate (PtdIns(3,4,5)P3)-dependent Rac exchanger 1 (PREX1) is a Rac-specific GTP-exchange factor (GEF) regulated by heterotrimeric G-protein β/γ subunits and the lipid second messenger PtdIns(3,4,5)P3 (1-4). PREX1 contains two DEP (Dishevelled, Egl-10, and Pleckstrin homology) domains that coordinate heterotrimeric G-protein signaling. It also contains a Dbl-homology domain, which exhibits Rac-GEF activity, and PH and PDZ domains for interacting with upstream and downstream signaling components (1). Originally shown to modulate cellular migration of neutrophils by Rac2 activation (5-8), it is clear that PREX1 plays a broader role in modulating cell migration. PREX1 promotes metastasis of prostate cancer and melanoma cells, affects endothelial junction integrity, and is required for platelet generation and function (9-14). Research studies suggest that PREX1 plays an essential role in mediating ErbB-dependent signaling events in breast cancer by coordinating Rac activation in response to paracrine signals within the tumor microenvironment. Activation of PREX1 downstream of ErbB3 and EGFR chemokine receptors (CXCR4) promotes Rac activation, increased migration, proliferation, tumorigenesis, and metastasis in breast cancer cells (15,16). Consistent with this observation, deletion of PREX1 expression in mice results in resistance to melanoma metastasis (11). Expression of PREX1 in human tumors transplanted into mice inversely correlates with increased tumor progression and poor survival (15). Additional research studies suggest that PREX Rac-GEF activity is enhanced by phosphorylation in response to growth factors or hormones, and may require coincident dephosphorylation of two PH domain serine residues. The upstream kinases and precise regulatory mechanism remains elusive (15,17).

$122
20 µl
$293
100 µl
APPLICATIONS
REACTIVITY
Human

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

Background: The annexin superfamily consists of 13 calcium or calcium and phospholipid binding proteins with high biological and structural homology (1). Annexin-1 (ANXA1) is the first characterized member of the annexin family of proteins and is able to bind to cellular membranes in a calcium-dependent manner, promoting membrane fusion and endocytosis (2-4). Annexin A1 has anti-inflammatory properties and inhibits phospholipase A2 activity (5,6). Annexin A1 can accumulate on internalized vesicles after EGF-stimulated endocytosis and may be required for a late stage in inward vesiculation (7). Phosphorylation by PKC, EGFR, and Chak1 results in inhibition of annexin A1 function (8-10). Annexin A1 has also been identified as one of the 'eat-me' signals on apoptotic cells that are to be recognized and ingested by phagocytes (11). Annexin A1, as an endogenous anti-inflammatory mediator, has roles in many diverse cellular functions, such as membrane aggregation, inflammation, phagocytosis, proliferation, apoptosis, and tumorigenesis and cancer development (12-14).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Western Blotting

Background: Chromosomal translocations result in misregulation of the proto-oncogene BCL6 in patients with B cell-derived non-Hodgkin's lymphoma (1). The BCL6 gene is selectively expressed in mature B cells and encodes a nuclear phosphoprotein that belongs to the BTB/POZ zinc finger family of transcription factors (2,3). BCL6 protein can bind to target DNA sequences of Stat6 and, analogous to Stat6, modulate the expression of interleukin-4-induced genes (4). Furthermore, BCL6 restrains p53-dependent senescence, making BCL6-active tumors functionally p53-negative (5). The mitogen-activated protein kinases, Erk1 and Erk2, but not JNK, phosphorylate BCL6 at multiple sites. Phosphorylation of BCL6 at Ser333 and Ser343 results in degradation of BCL6 by the ubiquitin/proteasome pathway in B cells (6,7). In addition, BCL6 is acetylated and its transcriptional repressor function is inhibited by the transcriptional co-activator p300 (8).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: The Silent Information Regulator (Sir2) family of genes is a highly conserved group of genes that encode nicotinamide adenine dinucleotide (NAD)-dependent protein deacetylases, also known as class III histone deacetylases. The first discovered and best characterized of this family is Saccharomyces cerevisiae Sir2, which is involved in silencing of mating type loci, telomere maintenance, DNA damage response, and cell aging (1). SirT6, a mammalian homolog of Sir2, is a nuclear, chromatin-associated protein that promotes the normal maintenance of genome integrity mediated by the base excision repair (BER) pathway (2-4). The BER pathway repairs single-stranded DNA lesions that arise spontaneously from endogenous alkylation, oxidation, and deamination events. SirT6 deficient mice show increased sensitivity to DNA-damaging agents, including the alkylating agents MMS and H2O2 (2). In addition, these mice show genome instability with increased frequency of fragmented chromosomes, detached centromeres, and gaps (2). SirT6 may regulate the BER pathway by deacetylating DNA Polβ or other core components of the pathway (2).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: The nucleosome, made up of four core histone proteins (H2A, H2B, H3, and H4), is the primary building block of chromatin. Originally thought to function as a static scaffold for DNA packaging, histones have now been shown to be dynamic proteins, undergoing multiple types of post-translational modifications, including acetylation, phosphorylation, methylation, and ubiquitination (1,2). Histone acetylation occurs mainly on the amino-terminal tail domains of histones H2A (Lys5), H2B (Lys5, 12, 15, and 20), H3 (Lys9, 14, 18, 23, 27, 36 and 56), and H4 (Lys5, 8, 12, and 16) and is important for the regulation of histone deposition, transcriptional activation, DNA replication, recombination, and DNA repair (1-3). Hyper-acetylation of the histone tails neutralizes the positive charge of these domains and is believed to weaken histone-DNA and nucleosome-nucleosome interactions, thereby destabilizing chromatin structure and increasing the accessibility of DNA to various DNA-binding proteins (4,5). In addition, acetylation of specific lysine residues creates docking sites for a protein module called the bromodomain, which binds to acetylated lysine residues (6). Many transcription and chromatin regulatory proteins contain bromodomains and may be recruited to gene promoters, in part, through binding of acetylated histone tails. Histone acetylation is mediated by histone acetyltransferases (HATs), such as CBP/p300, GCN5L2, PCAF, and Tip60, which are recruited to genes by DNA-bound protein factors to facilitate transcriptional activation (3). Deacetylation, which is mediated by histone deacetylases (HDAC and sirtuin proteins), reverses the effects of acetylation and generally facilitates transcriptional repression (7,8).

$293
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Immunofluorescence (Immunocytochemistry)

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, Mouse, Rat

Application Methods: Western Blotting

Background: Synapsins, a group of at least five related members (synapsins Ia, Ib, IIa, IIb, and IIIa), are abundant brain proteins essential for regulating neurotransmitter release (1,2). All synapsins contain a short amino-terminal domain that is highly conserved and phosphorylated by PKA or CaM kinase I (1). Phosphorylation of the synapsin amino-terminal domain at Ser9 inhibits its binding to phospholipids and dissociates synapsins from synaptic vesicles (2).

$260
100 µl
APPLICATIONS
REACTIVITY
Mouse

Application Methods: Immunofluorescence (Frozen), Immunofluorescence (Immunocytochemistry), Immunoprecipitation, Western Blotting

Background: Pro-Opio-Melano-Cortin (POMC) is a precursor protein expressed in the pituitary and the brain where it is processed into several peptide hormones and neuropeptides. Among these peptides are ACTH, α- and β-MSH, β-and γ-LPH, CLIP, β-endorphin, and N-POMC (1). POMC is involved in hypothalamic circuits regulating feeding behavior and POMC-producing neurons promote satiety (2). POMC neurons are also the target of leptin and insulin for the promotion of the browning of white fat (3).

$303
100 µl
APPLICATIONS
REACTIVITY
All Species Expected

Application Methods: Peptide ELISA (DELFIA), Western Blotting

Background: Protein kinase D1 (PKD1), also called PKCμ, is one member of the protein kinase D family. PKD members are serine/threonine protein kinases implicated in very diverse cellular functions including cell growth and survival, Golgi organization and immune response (1). The information about the natural substrates of PKD is limited (2,3). The enzyme recognizes and phosphorylates the following consensus sequence: LXRXXS/T. Phospho-(Ser/Thr) PKD Substrate Antibody recognizes phosphorylated PKD substrates at their consensus motif, providing a powerful new tool for PKD target discovery and characterization as well as HTS drug screening for potential kinase regulators.

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: A20, also referred to as TNF-α-induced protein 3 (TNFAIP3), is cytokine-inducible protein that functions to inhibit apoptosis and activate NF-κB (1,2). It was first identified as a TNF-α inducible primary response gene in human umbilical vein endothelial cells, and encodes a 790-amino acid protein containing seven Cys2/Cys2-zinc finger motifs (3). Constitutive expression of A20 is observed in lymphoid tissues (4), but it is transiently expressed in a variety of cell types in response to inflammatory signals such as TNF-α (3,5), IL-1 (3,5), phorbol esters (6), and LPS (7). Expression of A20 can confer resistance to apoptosis and NF-κB activation triggered by these signals, probably through interference with TRAF (TNF receptor associated factor) family members (8,9), and interaction with the NF-κB inhibiting protein ABIN (10). Studies also show that A20 contains site-specific ubiquitin modifying activity that can contribute to its biological functions (11,12). The amino-terminus of A20 contains de-ubiquitinating (DUB) activity for Lys63 branches, such as those found in TRAF6 and RIP, while the carboxyl-terminus contains ubiquitin ligase (E3) activity for Lys48 branches of the same substrates and leads to their degradation (12).

$305
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 HSP90 (C45G5) Rabbit mAb #4877.
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Western Blotting

Background: HSP70 and HSP90 are molecular chaperones expressed constitutively under normal conditions to maintain protein homeostasis and are induced upon environmental stress (1). Both HSP70 and HSP90 are able to interact with unfolded proteins to prevent irreversible aggregation and catalyze the refolding of their substrates in an ATP- and co-chaperone-dependent manner (1). HSP70 has a broad range of substrates including newly synthesized and denatured proteins, while HSP90 tends to have a more limited subset of substrates, most of which are signaling molecules. HSP70 and HSP90 often function collaboratively in a multi-chaperone system, which requires a minimal set of co-chaperones: HSP40, Hop, and p23 (2,3). The co-chaperones either regulate the intrinsic ATPase activity of the chaperones or recruit chaperones to specific substrates or subcellular compartments (1,4). When the ubiquitin ligase CHIP associates with the HSP70/HSP90 complex as a cofactor, the unfolded substrates are subjected to degradation by the proteasome (4). The biological functions of HSP70/HSP90 extend beyond their chaperone activity. They are essential for the maturation and inactivation of nuclear hormones and other signaling molecules (1,3). They also play a role in vesicle formation and protein trafficking (2).

SignalSilence® Akt siRNA I from Cell Signaling Technology (CST) allows the researcher to specifically inhibit Akt 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.

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

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Immunofluorescence (Immunocytochemistry), Western Blotting

Background: Topoisomerases are ubiquitous, conserved enzymes that remove DNA supercoils resulting from processes such as chromosome segregation, DNA replication, transcription, and repair (1). Topoisomerase inhibitors such as camptothecin and etoposide trap the enzyme as a DNA-bound intermediate, and these drugs are used to treat multiple human cancers (1,2). Tyrosyl-DNA-phosphodiesterases TDP1 and TDP2 function in the base excision repair (BER) and nonhomologous end joining (NHEJ) DNA repair pathways, respectively, and function in part in the repair of stalled topoisomerase-DNA complexes (3). Research has shown that inhibitors of tyrosyl-DNA-phosphodiesterases may act synergistically with topoisomerase inhibitors, allowing the potential for a more robust treatment of cancer (4,5). In small cell lung cancer, research suggests that TDP1 and topoisomerase 1 levels can predict sensitivity to topoisomerase 1 inhibitors (6).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: Sigma non-opioid intracellular receptor 1 (SIGMAR1) is an endoplasmic reticulum (ER) membrane chaperone that forms raft-like microdomains on the ER, where it interacts with mitochondria at the mitochondria-associated ER membrane domain (MAM). At MAM, SIGMAR1 maintains proper ER-mitochondrion Ca2+ signaling, regulates mitochondria function, and enhances cellular survival upon ER stress (1-4). When activated, SIGMAR1 translocates to ER and plasma membrane, where it interacts with a plethora of membrane proteins, including ion channels, neurotransmitter receptors, and kinases. SIGMAR1 also modulates a variety of neuronal functions, such as neuronal excitability, neuroplasticity, neuroprotection, and neurorestoration (5-7). SIGMAR1 binds to many anti-psychotic drugs and it is implicated in addiction, pain, neurodegenerative diseases, and depression (8-11). Recently, mutations in the SIGMAR1 gene have been reported to be associated with amyotrophic lateral sclerosis (12,13). Besides its important roles in central nervous system and peripheral nervous system, SIGMAR1 also enhances cancer cell migration and invasion (14,15).

$327
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 488 fluorescent dye and tested in-house for direct flow cytometric analysis in human cells. This antibody is expected to exhibit the same species cross-reactivity as the unconjugated Phospho-IRF-3 (Ser396) (D6O1M) Rabbit mAb #29047.
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Flow Cytometry

Background: Interferon regulatory factors (IRFs) comprise a family of transcription factors that function within the Jak/Stat pathway to regulate interferon (IFN) and IFN-inducible gene expression in response to viral infection (1). IRFs play an important role in pathogen defense, autoimmunity, lymphocyte development, cell growth, and susceptibility to transformation. The IRF family includes nine members: IRF-1, IRF-2, IRF-9/ISGF3γ, IRF-3, IRF-4 (Pip/LSIRF/ICSAT), IRF-5, IRF-6, IRF-7, and IRF-8/ICSBP. All IRF proteins share homology in their amino-terminal DNA-binding domains. IRF family members regulate transcription through interactions with proteins that share similar DNA-binding motifs, such as IFN-stimulated response elements (ISRE), IFN consensus sequences (ICS), and IFN regulatory elements (IRF-E) (2).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Peptide ELISA (DELFIA), Western Blotting

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).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: CrkL, a 39 kDa adaptor protein, has a key regulatory role in hematopoietic cells. CrkL has one SH2 and two SH3 domains, with 60% homology to CrkII (1). The amino-terminal SH3 domain of CrkL binds proteins such as C3G, SOS, PI3K, c-Abl and BCR/Abl. The SH2 domain of CrkL can bind to tyrosine-phosphorylated proteins such as Cbl, HEF1, CAS and paxillin (2,3). CrkL is involved in various signaling cascades initiated by different cytokines and growth factors. The biological outcomes of the Crk-activated signal transduction include the modulation of cell adhesion, cell migration and immune cell responses (4). CrkL is a prominent substrate of the BCR/Abl oncoprotein in chronic myelogenous leukemia and binds to both BCR/Abl and c-Abl (5). CrkL is prominently and constitutively tyrosine phosphorylated in CML neutrophils and is not phosphorylated in normal neutrophils. Moreover, stimulation of normal neutrophils with cytokines and agonists does not induce tyrosine phosphorylation of this protein (6), indicating that it may be a useful target for therapeutic intervention or as a disease marker. Tyr207 in CrkL is the BCR/Abl phosphorylation site (7).

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

Application Methods: Immunohistochemistry (Paraffin), Western Blotting

Background: Gelsolin (actin-depolymerizing factor, ADF, AGEL, Brevin) is an 83 kDa protein that shares structural and functional homology to villin and adseverin/scinderin (1,2). Gelsolin plays an important role in actin filament assembly by capping and severing actin proteins in a Ca2+-dependent manner (3,4). Gelsolin is important for cellular events (e.g., membrane ruffling, chemotaxis, ciliogenesis) that require cytoskeletal remodeling (3). Accordingly, cells from gelsolin knockout mice exhibit motility defects, including a failure to ruffle in response to growth factor stimulation (5,6). In humans, defects in gelsolin have been linked to amyloidosis type 5 (AMYL5), a hereditary disease characterized by cranial neuropathy, which appears to result from gelsolin amyloid deposition (7).

$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. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated p27 Kip1 (D69C12) XP® Rabbit mAb #3686.
APPLICATIONS
REACTIVITY
Human, Monkey, Rat

Application Methods: Flow Cytometry

Background: p27 Kip1 is a member of the Cip/Kip family of cyclin-dependent kinase inhibitors. Like its relatives, p57 Kip2 and p21 Waf1/Cip1, the ability to enforce the G1 restriction point is derived from its inhibitory binding to CDK2/cyclin E and other CDK/cyclin complexes. Expression levels of p27 are upregulated in quiescent cells and in cells treated with cAMP or other negative cell cycle regulators. Downregulation of p27 can be induced by treatment with interleukin-2 or other mitogens; this involves phosphorylation of p27 and its degradation by the ubiquitin-proteasome pathway (1-4).

$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-Stat1 (Tyr701) (58D6) Rabbit mAb #9167.
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Western Blotting

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.