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Product listing: Keratin 17/19 (D32D9) XP® Rabbit mAb, UniProt ID P08727 #3984 to Camptothecin #13637

$293
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Immunohistochemistry (Paraffin), Western Blotting

Background: Keratins (cytokeratins) are intermediate filament proteins that are mainly expressed in epithelial cells. Keratin heterodimers composed of an acidic keratin (or type I keratin, keratins 9 to 23) and a basic keratin (or type II keratin, keratins 1 to 8) assemble to form filaments (1,2). Keratin isoforms demonstrate tissue- and differentiation-specific profiles that make them useful as research biomarkers (1). Research studies have shown that mutations in keratin genes are associated with skin disorders, liver and pancreatic diseases, and inflammatory intestinal diseases (3-6).

$269
100 µl
APPLICATIONS
REACTIVITY
Human

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

Background: DNA-dependent protein kinase (DNA-PK) is an important factor in the repair of double-stranded breaks in DNA. Cells lacking DNA-PK or in which DNA-PK is inhibited fail to show proper nonhomologous end-joining (NHEJ) (1-7). DNA-PK is composed of two DNA-binding subunits (Ku70 and Ku86) and one 450 kDa catalytic subunit (DNA-PKcs) (8). It is thought that a heterodimer of Ku70 and Ku86 binds to double-stranded DNA broken ends before DNA-PKcs binds and is activated (1,9). Activated DNA-PKcs is a serine/threonine kinase that has been shown to phosphorylate a number of proteins in vitro, including p53, transcription factors, RNA polymerase, and Ku70/Ku86 (10,11). DNA-PKcs autophosphorylation at multiple sites, including Thr2609 and Ser2056, results in an inactivation of DNA-PK kinase activity and NHEJ ability (12,13). It has been demonstrated, however, that DNA-PK preferentially phosphorylates substrates before it autophosphorylates, suggesting that DNA-PK autophosphorylation may play a role in disassembly of the DNA repair machinery (14,15). Autophosphorylation at Thr2609 has also been shown to be required for DNA-PK-mediated double strand break repair, and phosphorylated DNA-PK co-localizes with H2A.X and 53BP1 at sites of DNA damage (16). Phosphorylation at Ser2056 occurs in response to double-stranded DNA breaks and ATM activation (17).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Connective tissue growth factor (CTGF, CCN2) belongs to the CCN (CYR61, CTGF, NOV) family of secreted extracellular matrix (ECM) proteins (1). Members of this family contain four conserved cysteine-rich domains, and interact in the ECM with a diverse array of cell surface receptors, including integrins and heparin-sulfate proteoglycans (2). These interactions regulate a multitude of cellular and tissue functions, including adhesion, proliferation, migration, differentiation, senescence, angiogenesis, inflammation, and wound repair (1, 3-5). The CTGF gene is a transcriptional target of both YAP/TAZ and TGFβ-SMAD signaling pathways (6,7), and aberrant regulation of CTGF expression is strongly associated with pathological conditions, notably cancer and fibrosis (8, 9).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Immunoprecipitation, Western Blotting

Background: PACT (protein activator of protein kinase R) is a double stranded RNA binding protein and a cellular activator of PKR (protein kinase R), a kinase that mediates the antiviral and antiproliferative actions of interferon (1). Stress signals such as serum starvation and arsenite treatment induces PACT to heterodimerize with PKR, resulting in the phosphorylation of eIF-2α and inhibition of protein synthesis (1,2). PACT has also been shown to play a role in RNA-mediated gene silencing by stimulating the activity of Dicer, thereby affecting the efficiency of miRNA accumulation and siRNA gene silencing (3,4). More recently, PACT has been shown to interact with RIG-I, a sensor of viral nucleic acids, and stimulates RIG-I-induced type I interferon production (5). Researchers have found that mutations in PACT are associated with dystonia, a movement disorder where patients develop involuntary muscle contractions and postures (6-8).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Immunoprecipitation, Western Blotting

Background: SMARCA1 (SNF2L) is one of the two orthologs of the ISWI (imitation switch) ATPases encoded by the mammalian genome (1). The ISWI chromatin remodeling complexes were first identified in Drosophila and have been shown to remodel and alter nucleosome spacing in vitro (2). SMARCA1 is the catalytic subunit of the nucleosome remodeling factor (NURF) and CECR2-containing remodeling factor (CERF) complexes (3-5). The NURF complex plays an important role in neuronal physiology by promoting neurite outgrowth and regulation of Engrailed homeotic genes that are involved in neuronal development in the mid-hindbrain (3). NURF is also thought to be involved in the maturation of T cells from thymocytes by regulating chromatin structure and expression of genes important for T cell development (6). The largest subunit of the NURF complex, BPTF, is required for proper development of mesoderm, endoderm, and ectoderm tissue lineages, suggesting a role for SMARCA1 in the development of the germ layers in mouse embryo (7). Disruption of the CERF complex by deletion of CECR2, an interacting partner of SMARCA1, is associated with the neural tube defect exencephaly, linking the CERF complex with regulation of neurulation (4).

Each control slide contains formalin fixed, paraffin-embedded cell pellets: Raw 264.7 (mPD-L1 negative) and mouse bone marrow-derived macrophages (mPD-L1 positive), which serve as controls for mPD-L1 immunostaining.

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

$448
50 sections
1 Kit
The PD-L1, CD3ε, CD8α Multiplex IHC Antibody Panel enables researchers to simultaneously detect these targets in paraffin-embedded tissues using tyramide signal amplification. Each antibody in the panel has been validated for this approach. For recommended staining conditions optimized specifically for this antibody panel please refer to Table 1 on the Data Sheet.
REACTIVITY
Human

Background: The field of cancer immunotherapy is focused on empowering the immune system to fight cancer. This approach has seen recent success in the clinic with targeting immune checkpoint control proteins, such as PD-1 (1,2). Despite this success, clinical biomarkers that predict response to therapeutic strategies involving PD-1 receptor blockade are still under investigation (3-5). While PD-L1 expression has been linked with an increased likelihood of response to anti-PD-1 therapy, research studies have shown that additional factors, such as tumor-immune infiltration and the ratio of effector to regulatory T cells within the tumor, could play a significant role in predicting treatment outcome (6-9).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Western Blotting

Background: Rho family small GTPases act as molecular switches that regulate processes such as cell migration, adhesion, proliferation and differentiation. Typically, they are activated by guanine nucleotide exchange factors (GEFs), which catalyze the exchange of bound GDP for GTP, and are inhibited by GTPase activating proteins (GAPs), which catalyze the hydrolysis of GTP to GDP (1). Rnd1, Rnd2 and RhoE/Rnd3 comprise the evolutionarily divergent Rnd family of Rho-type small GTPases, which lack GTPase activity and therefore remain in a GTP-bound state (2, reviewed in 3). RhoE/Rnd3 activity leads to a decrease in stress fibers and increased cell migration, at least in part through regulation of the Rho-dependent kinase ROCK1 (4). Activity of RhoE/Rnd3 itself is regulated by ROCK1, which phosphorylates RhoE/Rnd3 at Ser11, enhancing its activity (5). RhoE/Rnd3 has been implicated in inhibition of DNA-damage induced apoptosis (6) and cell cycle arrest (7). In keratinocytes, RhoE/Rnd3 regulates differentiation through its effects on both proliferation and adhesion (8).

$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 analysis in human cells. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated LEF1 (C12A5) Rabbit mAb #2230
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Flow Cytometry

Background: LEF1 and TCF are members of the high mobility group (HMG) DNA binding protein family of transcription factors that consists of the following: Lymphoid Enhancer Factor 1 (LEF1), T Cell Factor 1 (TCF1/TCF7), TCF3/TCF7L1, and TCF4/TCF7L2 (1). LEF1 and TCF1/TCF7 were originally identified as important factors regulating early lymphoid development (2) and act downstream in Wnt signaling. LEF1 and TCF bind to Wnt response elements to provide docking sites for β-catenin, which translocates to the nucleus to promote the transcription of target genes upon activation of Wnt signaling (3). LEF1 and TCF are dynamically expressed during development and aberrant activation of the Wnt signaling pathway is involved in many types of cancers including colon cancer (4,5).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: TROP2 is a transmembrane glycoprotein encoded by gene TACSTD2 (tumor associated calcium signal transducer 2). TROP2 was first discovered as a biomarker of invasive trophoblast cells and later reported in many types of cancer cells as well as in various organs during development, and adult stem cells during homeostasis (1, 2). TROP2 has an extracellular domain with EGF thyroglobulin type-1 repeats, a transmembrane domain and a short cytoplasmic tail with a HIKE domain containing a PIP2 binding site and PKC phosphoryaltion site (Ser303) (1-4). TROP2 functions by regulating multiple signaling pathways including-interaction of extracellular domain with integrin beta1 to regulate FAK signaling, association of its transmembrane domain with claudin1 and claudin7 for tight junction formation, as well as regulation of intracellular calcium release by its PIP2 binding and activation of the ERK/MAPK pathway (1,2, 5-8). All of these functions are important for its role in tumor proliferation, metastasis and invasion (1,2). PKC can phosphorylate TROP2 at Ser303; the phosphorylation changes the cytoplasmic tail conformation and further promotes its signaling (9). TROP2 can be activated through intramembrane proteolysis first by TACE, followed further cleavage by presenilin 1 and presenilin2. The proteolysis process is required for its role in tumor cell proliferation (10,11).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

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

Background: Numb contains an amino-terminal phosphotyrosine-binding (PTB) domain and carboxy-terminal endocytic binding motifs for α-adaptin and EH (Eps15 homology) domain-containing proteins, indicating a role in endocytosis (1,2). There are four mammalian Numb splicing isoforms that are differentially expressed and may have distinct functions (3-5). Numb acts as a negative regulator of Notch signaling by promoting ubiquitination and degradation of Notch (6). The protein is asymmetrically segregated into one daughter cell during cell division, producing two daughter cells with different responses to Notch signaling and different cell fates (7,8). The localization of Numb can also be regulated by G-protein coupled receptor (GPCR) and PKC signaling (9).

$327
400 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat, S. cerevisiae

Application Methods: Immunoprecipitation

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).

$489
96 assays
1 Kit
CST's PathScan® Cleaved Caspase-3 (Asp175) Sandwich ELISA Kit is a solid phase sandwich enzyme-linked immunosorbent assay (ELISA) that detects endogenous levels of cleaved caspase-3 protein. A Cleaved Caspase-3 (Asp175) Rabbit mAb has been coated onto the microwells. After incubation with cell lysates, the cleaved caspase-3 protein is captured by the coated antibody. Following extensive washing, a Biotinylated Caspase-3 Rabbit Antibody is added to detect the captured cleaved caspase-3 protein. HRP-linked streptavidin 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 cleaved caspase-3 protein.Antibodies in kit are custom formulations specific to kit.
REACTIVITY
Human

Background: Caspase-3 (CPP-32, Apoptain, Yama, SCA-1) is a critical executioner of apoptosis, as it is either partially or totally responsible for the proteolytic cleavage of many key proteins, such as the nuclear enzyme poly (ADP-ribose) polymerase (PARP) (1). Activation of caspase-3 requires proteolytic processing of its inactive zymogen into activated p17 and p12 fragments. Cleavage of caspase-3 requires the aspartic acid residue at the P1 position (2).

$269
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunohistochemistry (Paraffin)

Background: Caspase-3 (CPP-32, Apoptain, Yama, SCA-1) is a critical executioner of apoptosis, as it is either partially or totally responsible for the proteolytic cleavage of many key proteins, such as the nuclear enzyme poly (ADP-ribose) polymerase (PARP) (1). Activation of caspase-3 requires proteolytic processing of its inactive zymogen into activated p17 and p12 fragments. Cleavage of caspase-3 requires the aspartic acid residue at the P1 position (2).

$260
100 µl
APPLICATIONS
REACTIVITY
Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: Voltage gated sodium channels are composed of a large alpha subunit and auxiliary beta subunits. The alpha subunit has 4 homologous domains, with each domain containing 6 transmembrane segments. These segments function as the voltage sensor and sodium permeable pore. Upon change of membrane potential, the sodium channel is activated, which allows sodium ions to flow through (1,2). When associated with beta subunits or other accessory proteins, the alpha subunit is regulated at the level of cell surface expression, kinetics, and voltage dependence (3,4).There are 9 mammalian alpha subunits, named Nav1.1-Nav1.9 (5). These alpha subunits differ in tissue specificity and biophysical functions (6,7). Seven of these subunits are essential for the initiation and propagation of action potentials in the central and peripheral nervous system while Nav1.4 and Nav1.5 are mainly expressed in skeletal muscle and cardiac muscle (8,9). Mutations in these alpha channel subunits have been identified in patients with epilepsy, seizure, ataxia, sensitivity to pain, and cardiomyopathy (reviewed in 10).

$269
100 µl
APPLICATIONS
REACTIVITY
Human

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

Background: CD80 (B7-1, BB1) and CD86 (B7-2, B70) are members of the B7 family of cell surface ligands that regulate T cell activation and immune responses. CD80 is expressed on activated antigen presenting cells, including dendritic cells, B cells, monocytes, and macrophages. CD86 is expressed on resting monocytes, dendritic cells, activated B lymphocytes, and can be further upregulated in the presence of inflammation (1-3). CD80 and CD86 are ligands for CD28, which functions as a T cell costimulatory receptor. Interaction of CD28 with CD80 or CD86 provides the second signal required for naïve T cell activation, T cell proliferation, and acquisition of effector functions (3-7). Alternatively, CD80 and CD86 also act as ligands to CTLA-4, which results in the downregulation of T cell activity (3,7-9).

$297
100 µl
APPLICATIONS
REACTIVITY
All Species Expected

Application Methods: DNA Dot Blot, Immunofluorescence (Immunocytochemistry)

Background: Methylation of DNA at cytosine residues is a heritable, epigenetic modification that is critical for proper regulation of gene expression, genomic imprinting, and mammalian development (1,2). 5-methylcytosine is a repressive epigenetic mark established de novo by two enzymes, DNMT3a and DNMT3b, and is maintained by DNMT1 (3, 4). 5-methylcytosine was originally thought to be passively depleted during DNA replication. However, subsequent studies have shown that Ten-Eleven Translocation (TET) proteins TET1, TET2, and TET3 can catalyze the oxidation of methylated cytosine to 5-hydroxymethylcytosine (5-hmC) (5). Additionally, TET proteins can further oxidize 5-hmC to form 5-formylcytosine (5-fC) and 5-carboxylcytosine (5-caC), both of which are excised by thymine-DNA glycosylase (TDG), effectively linking cytosine oxidation to the base excision repair pathway and supporting active cytosine demethylation (6,7).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Immunofluorescence (Immunocytochemistry), Western Blotting

Background: Stearoyl-CoA desaturase 1 (SCD1) is a key lipogenic enzyme found in the endoplasmic reticulum that catalyzes the conversion of palmitoyl–CoA and stearoyl–CoA to palmitoleoyl–CoA (16:1) and oleoyl–CoA (18:1) (1-3). Palmitoleate and oleate are the major components of triglycerides, membrane phospholipids and cholesterol esters (1). SCD1-knockout mice show improved insulin sensitivity and reduced body fat (1). Disruption of SCD1 in mouse brown adipose tissue strengthens insulin signaling and results in increased translocation of Glut4 to plasma membrane and enhanced uptake of glucose (4). Furthermore, SCD1 is essential for the onset of diet-induced body weight gain (1) and insulin resistance in the liver (5).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Chromatin IP, Chromatin IP-seq, Flow Cytometry, Immunofluorescence (Immunocytochemistry), Immunoprecipitation, Western Blotting

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

$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Tie2/Tek is a receptor tyrosine kinase (RTK) expressed almost exclusively on endothelial cells. It is critical for vasculogenesis and could be important for maintaining endothelial cell survival and integrity in adult blood vessels as well as tumor angiogenesis (1-3). A family of ligands known as the angiopoietins binds to Tie2. Interestingly, these ligands appear to have opposing actions; Angiopoietin-1 (Ang1) and Angiopoietin-4 (Ang4) stimulate tyrosine phosphorylation of Tie2; Angiopoietin-2 (Ang2) and Angiopoietin-3 (Ang3) can inhibit this phosphorylation (4,5). Downstream signaling components, including Grb2, Grb7, Grb14, SHP-2, the p85 subunit of phosphatidylinositol 3-kinase, and p56/Dok-2 interact with Tie2 in a phosphotyrosine-dependent manner through their SH2 or PTB domains (6,7). Tyr992 is located on the putative activation loop of Tie2 and is a major autophosphorylation site (8).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Insulin-like growth factor (IGF) signaling plays a major role in regulating the proliferation and metabolism of normal and malignant cells. Insulin-like growth factor-binding proteins (IGFBPs) play an integral role in modifying IGF actions in a wide variety of cell types. The six IGFBP family members share a high affinity for IGF binding and are structurally related, but are encoded by distinct genes (1). IGF binding proteins can exert stimulatory or inhibitory effects by controlling IGF availability through high affinity binding of IGF at the carboxy-terminal domain (2,3). IGFBP3 is the most abundant serum IGF binding protein and the main mediator for IGF-I bioactivities. IGFBP3 also binds IGF-II, insulin, and other cellular and extracellular components to regulate cell growth, development, and apoptosis through both IGF-dependent and IGF-independent mechanisms (4-8). Research studies describe correlations between increased IGF-I levels and reduced levels of IGFBP3 with increased risks of developing cancer, including breast, colon, lung, and prostate cancer (2).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Paired box (PAX) proteins are a family of transcription factors that play important and diverse roles in animal development (1). Nine PAX proteins (PAX1-9) have been described in humans and other mammals. They are defined by the presence of an amino-terminal "paired" domain, consisting of two helix-turn-helix motifs, with DNA binding activity (2). PAX proteins are classified into four structurally distinct subgroups (I-IV) based on the absence or presence of a carboxy-terminal homeodomain and a central octapeptide region. Subgroup I (PAX1 and 9) contains the octapeptide but lacks the homeodomain; subgroup II (PAX2, 5, and 8) contains the octapeptide and a truncated homeodomain; subgroup III (PAX3 and 7) contains the octapeptide and a complete homeodomain; and subgroup IV (PAX4 and 6) contains a complete homeodomain but lacks the octapeptide region (2). PAX proteins play critically important roles in development by regulating transcriptional networks responsible for embryonic patterning and organogenesis (3); a subset of PAX proteins also maintain functional importance during postnatal development (4). Research studies have implicated genetic mutations that result in aberrant expression of PAX genes in a number of cancer subtypes (1-3), with members of subgroups II and III identified as potential mediators of tumor progression (2).

$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 Ki-67 (D3B5) Rabbit mAb #9129.
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Flow Cytometry

Background: Ki-67, named after the location where it was discovered (Kiel University, Germany), is a nuclear nonhistone protein (1) that is universally expressed among proliferating cells and absent in quiescent cells (2). Ki-67 detects proliferating cells in G1, S, G2, and mitosis, but not in the G0 resting phase. Research studies have shown that high levels of Ki-67 are associated with poorer breast cancer survival (3). Research studies have explored the use of Ki-67, along with other markers, as potential prognostic or predictive markers in breast cancer and other malignant diseases (4).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Notch proteins (Notch1-4) are a family of transmembrane receptors that play important roles in development and the determination of cell fate (1). Mature Notch receptors are processed and assembled as heterodimeric proteins, with each dimer comprised of a large extracellular ligand-binding domain, a single-pass transmembrane domain, and a smaller cytoplasmic subunit (Notch intracellular domain, NICD) (2). Binding of Notch receptors to ligands of the Delta-Serrate-Lag2 (DSL) family triggers heterodimer dissociation, exposing the receptors to proteolytic cleavages; these result in release of the NICD, which translocates to the nucleus and activates transcription of downstream target genes (3,4).

$305
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 594 fluorescent dye and tested in-house for direct immunofluorescent analysis in rat brain. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated Neurofilament-L (C28E10) Rabbit mAb #2837.
APPLICATIONS
REACTIVITY
Mouse, Rat

Application Methods: Immunofluorescence (Frozen)

Background: The cytoskeleton consists of three types of cytosolic fibers: actin microfilaments, intermediate filaments, and microtubules. Neurofilaments are the major intermediate filaments found in neurons and consist of light (NFL), medium (NFM), and heavy (NFH) subunits (1). Similar in structure to other intermediate filament proteins, neurofilaments have a globular amino-terminal head, a central α-helical rod domain, and a carboxy-terminal tail. A heterotetrameric unit (NFL-NFM and NFL-NFH) forms a protofilament, with eight protofilaments comprising the typical 10 nm intermediate filament (2). While neurofilaments are critical for radial axon growth and determine axon caliber, microtubules are involved in axon elongation. PKA phosphorylates the head domain of NFL and NFM to inhibit neurofilament assembly (3,4). Research studies have shown neurofilament accumulations in many human neurological disorders including Parkinson's disease (in Lewy bodies along with α-synuclein), Alzheimer's disease, Charcot-Marie-Tooth disease, and Amyotrophic Lateral Sclerosis (ALS) (1).

$305
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 E-Cadherin (24E10) Rabbit mAb #3195.
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Western Blotting

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

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Rat

Application Methods: Western Blotting

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

$260
100 µl
APPLICATIONS
REACTIVITY
Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: Rhodopsin is the photoreceptor in the retinal rods. It is activated by photons, transduces visual information through its cognate G protein, transducin, and is inactivated by arrestin binding (1). Using atomic-force microscopy, rhodopsin was found to be arranged into paracrystalline arrays of dimers in mouse disc membranes (2). Rhodopsin is considered to be the prototype of G protein-coupled receptors (GPCRs), and is the first GPCR for which a crystal structure was solved (3). Research studies have linked mutations in the gene encoding rhodopsin to retinitis pigmentosa (4,5), a disease characterized by retinal degeneration resulting in reduced peripheral vision and night blindness (6).

$262
3 nmol
300 µl
SignalSilence® PLK1 siRNA I from Cell Signaling Technology (CST) allows the researcher to specifically inhibit PLK1 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: At least four distinct polo-like kinases exist in mammalian cells: PLK1, PLK2, PLK3, and PLK4/SAK (1). PLK1 apparently plays many roles during mitosis, particularly in regulating mitotic entry and exit. The mitosis promoting factor (MPF), cdc2/cyclin B1, is activated by dephosphorylation of cdc2 (Thr14/Tyr15) by cdc25C. PLK1 phosphorylates cdc25C at Ser198 and cyclin B1 at Ser133 causing translocation of these proteins from the cytoplasm to the nucleus (2-5). PLK1 phosphorylation of Myt1 at Ser426 and Thr495 has been proposed to inactivate Myt1, one of the kinases known to phosphorylate cdc2 at Thr14/Tyr15 (6). Polo-like kinases also phosphorylate the cohesin subunit SCC1, causing cohesin displacement from chromosome arms that allow for proper cohesin localization to centromeres (7). Mitotic exit requires activation of the anaphase promoting complex (APC) (8), a ubiquitin ligase responsible for removal of cohesin at centromeres, and degradation of securin, cyclin A, cyclin B1, Aurora A, and cdc20 (9). PLK1 phosphorylation of the APC subunits Apc1, cdc16, and cdc27 has been demonstrated in vitro and has been proposed as a mechanism by which mitotic exit is regulated (10,11).Substitution of Thr210 with Asp has been reported to elevate PLK1 kinase activity and delay/arrest cells in mitosis, while a Ser137Asp substitution leads to S-phase arrest (12). In addition, while DNA damage has been found to inhibit PLK1 kinase activity, the Thr210Asp mutant is resistant to this inhibition (13). PLK1 has been reported to be phosphorylated in vivo at Ser137 and Thr210 in mitosis; DNA damage prevents phosphorylation at these sites (14).