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Product listing: Wnt3a Antibody, UniProt ID P56704 #2391 to Src Family Antibody Sampler Kit, UniProt ID P06239 #9320

$260
100 µl
APPLICATIONS
REACTIVITY
Mouse

Application Methods: Western Blotting

Background: The Wnt family includes several secreted glycoproteins that play important roles in animal development (1). There are 19 Wnt genes in the human genome that encode functionally distinct Wnt proteins (2). Wnt members bind to the Frizzled family of seven-pass transmembrane proteins and activate several signaling pathways (3). The canonical Wnt/β-catenin pathway also requires a coreceptor from the low-density lipoprotein receptor family (4). Aberrant activation of Wnt signaling pathways is involved in several types of cancers (5).

$260
100 µl
APPLICATIONS

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

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

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: 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, Monkey

Application Methods: Western Blotting

Background: Members of the Toll-like receptor (TLR) family, named for the closely related Toll receptor in Drosophila, play a pivotal role in innate immune responses (1-4). TLRs recognize conserved motifs found in various pathogens and mediate defense responses (5-7). Triggering of the TLR pathway leads to the activation of NF-κB and subsequent regulation of immune and inflammatory genes (4). The TLRs and members of the IL-1 receptor family share a conserved stretch of approximately 200 amino acids known as the Toll/Interleukin-1 receptor (TIR) domain (1). Upon activation, TLRs associate with a number of cytoplasmic adaptor proteins containing TIR domains, including myeloid differentiation factor 88 (MyD88), MyD88-adaptor-like/TIR-associated protein (MAL/TIRAP), Toll-receptor-associated activator of interferon (TRIF), and Toll-receptor-associated molecule (TRAM) (8-10). This association leads to the recruitment and activation of IRAK1 and IRAK4, which form a complex with TRAF6 to activate TAK1 and IKK (8,11-14). Activation of IKK leads to the degradation of IκB, which normally maintains NF-κB in an inactive state by sequestering it in the cytoplasm.

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

Application Methods: Immunoprecipitation, Western Blotting

Background: Cool/Pix proteins comprise a family of guanine nucleotide exchange factors (GEFs) localized to focal adhesions. The family consists of two isoforms, cool2/αpix and cool1/βPix, the latter having two splice variants that vary in their carboxy termini (1). Cool1/βPix, like other GEFs, has a DH (Dbl homology) domain, which allows binding of small GTPases and GDP/GTP exchange, and a PH (Pleckstrin homology) domain, which is important in regulating subcellular localization. Cool1/βPix also has an SH3 domain, which binds to the PAK kinase, a downstream effector of cdc42 and Rac (3,4). Phosphorylation of cool1/βPix by PAK2 downstream of MAPK signaling alters the localization of a complex containing PAK2 and cool-1/βPix, regulating formation of growth cones in response to growth factors (4). Growth factor induced activation of Rac1 via cool1/βPix was later shown to occur independently of subcellular localization (5). Endothelin-1 stimulation of mesangial cells stimulates the protein kinase A (PKA) pathway, resulting in translocation of cool-1/βPix and activation of cdc42 (6).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: GFAT1, glutamine:fructose-6-phosphate aminotransferase 1, is the rate-limiting enzyme of the hexosamine biosynthesis pathway (1). This enzyme catalyzes the conversion of fructose-6-phosphate and glutamine to glucosamine-6-phosphate and glutamate (2). The hexosamine biosynthesis pathway generates the building blocks for protein and lipid glycosylation (2). Furthermore, studies suggest that increased activity of this pathway is a contributing factor to hyperglycemia-induced insulin resistance (1,2). GFAT1 is more active in non-insulin-dependent diabetes mellitus (NIDDM) patients (3). Transgenice mice overexpressing this enzyme in skeletal muscle and adipose tissue show an insulin resistance phenotype (4,5). GFAT2, an isoenzyme of GFAT1, was later identified (6, 7). Studies show that the regulation of GFAT2 is different from that of GFAT1, suggesting differential regulation of the hexosamine pathway in different tissues (7).

$111
20 µl
$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunofluorescence (Immunocytochemistry), Western Blotting

Background: Regulation of actin dynamics at the leading edge of the cell drives cell adhesion, migration, and invasion. These processes are crucial for normal development, immune cell function, angiogenesis and cell division, and are dysregulated in diseases such as metastatic cancer (1, 2).Lamellipodin (Lpd) is a member of the Mig-10/RIAM/lamellipodin (MRL) family of adaptor proteins. Lamellipodin regulates the formation of lamellipodia at the leading edge through its interaction with and recruitment of actin-modulating proteins such as Ena/VASP (3) and the Scar/WAVE complex (4). Lamellipodin and Mena cooperate with endophilin to regulate EGFR endocytosis (5). MRL proteins can also form complexes with talin and activated integrins, guiding the formation of cell protrusions and the direction of cell migration (6).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: Endonuclease G (EndoG) is a nuclear-encoded mitochondrial nuclease that has been reported to function in apoptosis, DNA recombination and cell proliferation (1-5). EndoG is expressed as a precursor protein containing an amino-terminal mitochondrial targeting sequence which is removed when the protein is imported into the mitochondria (1). During apoptosis EndoG is released from the mitochondria, translocates to the nucleus and cooperates with other nucleases to trigger DNA fragmentation associated with the apoptotic process (3,6,7).

The Mutant Ras Antibody Sampler Kit provides an economical means of detecting common mutation in the Ras protein. The kit contains enough primary and secondary antibodies to perform at least two western blot experiments.

Background: The 21 kDa guanine-nucleotide binding proteins (K-Ras, H-Ras, and N-Ras) cycle between active (GTP-bound) and inactive (GDP-bound) forms (1). Receptor tyrosine kinases and G protein-coupled receptors activate Ras, which then stimulates the Raf-MEK-MAPK pathway (2-4). GTPase-activating proteins (GAP) normally facilitate the inactivation of Ras. However, research studies have shown that in 30% of human tumors, point mutations in Ras prevent the GAP-mediated inhibition of this pathway (5). The most common oncogenic Ras mutation found in tumors is Gly12 to Asp12 (G12D), which prevents Ras inactivation, possibly by increasing the overall rigidity of the protein (5,6). Additional oncogenic mutations of Ras have been observed at varying frequencies at codons 12, 13, and 61. The Gly12 to Val12 (G12V) mutation has been detected in a number of different cancers, including colorectal and thyroid cancer (7,8).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: FTO (fat mass and obesity-associated protein) is the first obesity gene product identified by genome-wide association studies and it is associated with the largest effect size for this class of proteins (1-4). Multiple single-nucleotide polymorphisms (SNPs) in the first intron of the FTO gene have been associated with increased body weight and obesity. Further studies reported that FTO risk alleles were associated with an increase in energy intake, a reduction of activity, and possibly an increased daily fat intake (4).FTO is a DNA and RNA demethylase that catalyzes the oxidative demethylation of thymidine and uracil. Among its targets is an mRNA subset involved in regulation of learning, reward behavior, motor functions, and feeding (5). Loss of the FTO gene in mice leads to postnatal growth retardation and a significant reduction in adipose tissue. Mice deficient in the FTO gene have lean body mass due to increased energy expenditure and systemic activation of sympathetic neurons, while overexpression of FTO in mice leads to increased food intake and results in obesity. These results demonstrate that FTO is functionally involved in energy homeostasis (6-8).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: The NF-κB/Rel transcription factors are present in the cytosol in an inactive state complexed with the inhibitory IκB proteins (1-3). Activation occurs via phosphorylation of IκBα at Ser32 and Ser36 followed by proteasome-mediated degradation that results in the release and nuclear translocation of active NF-κB (3-7). IκBα phosphorylation and resulting Rel-dependent transcription are activated by a highly diverse group of extracellular signals including inflammatory cytokines, growth factors, and chemokines. Kinases that phosphorylate IκB at these activating sites have been identified (8).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunohistochemistry (Paraffin), Western Blotting

Background: Prolactin receptor (PRLR) is a single-pass transmembrane receptor that mediates the actions of prolactin, a peptide hormone secreted by the anterior pituitary. PRLR is a type 1 cytokine receptor that is best known for promoting lactation in mammals, but which is also implicated in osmoregulation, metabolism, and immune system function (1). Research studies suggest that PRLR activation may promote tumor growth (2). Prolactin signaling via PRLR can activate multiple signal transduction pathways in breast cancer cells, including the Jak/Stat, PI3K/Akt, and MAPK pathways, leading to both pro-proliferative and anti-apoptotic downstream effects (3,4). Nine isoforms of PRLR have been identified, with the canonical (long) isoform primarily responsible for the pro-oncogenic effects of PRLR in some cancer cell lines (3). Much less is known about the functions of the other prolactin receptor isoforms. Defining the precise role of PRLR in promoting growth of breast cancer and other tumor types remains an area of active investigation (2).

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

Application Methods: Immunohistochemistry (Paraffin), Western Blotting

Background: TRXR1 (thioredoxin reductase 1) is a selenocysteine-containing protein that is involved in redox homeostasis (1-6). Its canonical target is thioredoxin, another redox protein (1). Together, they are involved in many functions such as antioxidant regulation (3-6), cell proliferation (2,3,5), DNA replication (2,3), and transcription (3,5). TRXR1 is also capable of reducing a wide array of cellular proteins (1,3). Selenium deficiency, either by diet modification (2,6) or introduction of methylmercury (4), hinders proper expression and function of TRXR1. It is possible that this effect, which results in a higher oxidative state, is a result of the selenocysteine codon (UGA) being read as a STOP codon in the absence of adequate selenium (4). The functions of TRXR1 in cell proliferation and antioxidant defense make it a potential therapeutic target.

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

Application Methods: Immunofluorescence (Immunocytochemistry), Western Blotting

Background: Histone macroH2A1 and macroH2A2 comprise a family of variant histone H2A proteins. MacroH2A1 exists as two distinct isoforms due to alternative splicing of a single gene; macroH2A1.1 levels accumulate throughout differentiation and development while macroH2A1.2 shows a constant level of expression (1). MacroH2A1 and macroH2A2 are encoded by completely distinct genes located on separate chromosomes (2,3). Both macroH2A1 and macroH2A2 proteins contain an amino-terminal histone-like region with 64% sequence identity to canonical histone H2A, in addition to a carboxy-terminal “macro” domain (1-3). MacroH2A1 and macroH2A2 are enriched in facultative heterochromatin, including inactivated X chromosomes in mammalian females and senescence-associated heterochromatin foci (2-5). Both act to repress gene transcription by inhibiting the binding of transcription factors to chromatin, the acetylation of histones by p300, and the chromatin-remodeling activities of SWI/SNF and ACF (6,7). The macro domain of macroH2A1.1 binds to ADP-ribose and functions to recruit macroH2A1.1 to activated PARP at sites of DNA damage, where it mediates chromatin rearrangements to locally regulate the DNA damage response (8). MacroH2A1.2 and macroH2A2 do not bind poly-ADP-ribose and are not recruited to sites of activated PARP (8).

$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).

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

Application Methods: Western Blotting

Background: Interleukin-1 (IL-1) receptor-associated kinase (IRAK) is a serine/threonine-specific kinase that can be coprecipitated in an IL-1-inducible manner with the IL-1 receptor (1). The mammalian family of IRAK molecules contains four members (IRAK1, IRAK2, IRAK3/IRAK-M, and IRAK4). The binding of IL-1 to IL-1 receptor type I (IL-1RI) initiates the formation of a complex that includes IL-1RI, AcP, MyD88, and IRAKs (2). IRAK undergoes autophosphorylation shortly after IL-1 stimulation. The subsequent events involve IRAK dissociation from the IL-1RI complex, its ubiquitination, and its association with two membrane-bound proteins: TAB2 and TRAF6. The resulting IRAK-TRAF6-TAB2 complex is then released into the cytoplasm where it activates protein kinase cascades, including TAK1, IKKs, and the stress-activated kinases (3).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

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

Background: The sequence-specific transcription factor activator protein 2β (AP-2β) is required for normal kidney development (1). AP-2β knockout mice die 1-2 days after birth due to polycystic kidney disease (1). Massive apoptosis occured during kidney deveopment at the end of embryogenesis in these mice (1). Overexpressed AP-2β has been to found to suppress c-myc-induced apoptosis, indicating a role of this transcription factor in cell survival (1). In addition, overexpression of AP-2β is shown to be related to impaired insulin signaling in adipocytes, and is therefore proposed to be a candidate gene that may relate to obesity (2).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse

Application Methods: Immunoprecipitation, Western Blotting

Background: p58IPK is an inhibitor of interferon-induced and double-stranded RNA-activated protein kinase (PKR). It physically interacts with PKR and inhibits its activation and activity (1). Influenza virus activates p58IPK and thus blocks the activity of PKR to repress translation in the infected cells. In the uninfected cells, p58IPK forms a complex with its own inhibitor, HSP40, and is kept in an inactive state (2). ER stress induces the expression of p58IPK mediated by ATF6 (3,4). The induced p58IPK negatively regulates Perk activity, inhibits eIF2α phosphorylation and suppresses the activation of expression of downstream ER-responsive genes ATF4 and GADD153 (4). More recently, p58IPK has been shown to associate with the lumen of the endoplasmic reticulum (ER) where it is believed to serve as a cochaperone for BiP (5).

$111
20 µl
$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: The NEK family of protein kinases is composed of 11 members in humans that share an amino-terminal catalytic domain related to NIMA, a serine/threonine kinase identified in Aspergillus nidulans. While NIMA is critical for cell cycle progression in fungus, the function of NEK kinases in mammalian cells is largely unknown. NEK1 was first identified by screening mouse cDNA expression libraries and was demonstrated to have dual specificity kinase activity on both tyrosine and serine/threonine sites (1). NEK2 most closely resembles fungal NIMA in its primary structure and is believed to promote the splitting of duplicated centrosomes at the onset of mitosis (2,3). NEK3 is predominantly a cytoplasmic enzyme and its activity shows marginal variation throughout the cell cycle (4). NEK4 is ubiquitously expressed and its expression and subcellular location are not associated with cell cycle (5). NEK6/7 have been suggested to phosphorylate and activate p70 S6 kinase in vitro (6). Expression of an inactive NEK6 mutant arrests cells in M phase and interferes with chromosome segregation (7). NEK8 activity is not cell cycle regulated and may play a role in cell cycle independent microtubule dynamics (8). NEK9 is activated during mitosis and may participate in the activation of NEK6/7 during mitosis (9,10).

$111
20 µl
$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Modulation of chromatin structure plays a critical role in the regulation of transcription and replication of the eukaryotic genome. The nucleosome, made up of four core histone proteins (H2A, H2B, H3, and H4), is the primary building block of chromatin. In addition to the growing number of post-translational histone modifications regulating chromatin structure, cells can also exchange canonical histones with variant histones that can directly or indirectly modulate chromatin structure (1). CENP-A, also known as the chromatin-associated protein CSE4 (capping-enzyme suppressor 4-p), is an essential histone H3 variant that replaces canonical histone H3 in centromeric heterochromatin (2). The greatest divergence between CENP-A and canonical histone H3 occurs in the amino-terminal tail of the protein, which binds linker DNA between nucleosomes and facilitates proper folding of centromeric heterochromatin (3). The amino-terminal tail of CENP-A is also required for recruitment of other centromeric proteins (CENP-C, hSMC1, hZW10), proper kinetochore assembly and chromosome segregation during mitosis (4). Additional sequence divergence in the histone fold domain is responsible for correct targeting of CENP-A to the centromere (5). Many of the functions of CENP-A are regulated by phosphorylation (6,7). Aurora A-dependent phosphorylation of CENP-A on Ser7 during prophase is required for proper targeting of Aurora B to the inner centromere in prometaphase, proper kinetochore/microtubule attachment and proper alignment of chromosomes during mitosis (6).

$111
20 µl
$260
100 µl
APPLICATIONS
REACTIVITY
Bovine, Human, Mink, Monkey, Mouse, Pig, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: Transcription factors of the nuclear factor κB (NF-κB)/Rel family play a pivotal role in inflammatory and immune responses (1,2). There are five family members in mammals: RelA, c-Rel, RelB, NF-κB1 (p105/p50), and NF-κB2 (p100/p52). Both p105 and p100 are proteolytically processed by the proteasome to produce p50 and p52, respectively. Rel proteins bind p50 and p52 to form dimeric complexes that bind DNA and regulate transcription. In unstimulated cells, NF-κB is sequestered in the cytoplasm by IκB inhibitory proteins (3-5). NF-κB-activating agents can induce the phosphorylation of IκB proteins, targeting them for rapid degradation through the ubiquitin-proteasome pathway and releasing NF-κB to enter the nucleus where it regulates gene expression (6-8). NIK and IKKα (IKK1) regulate the phosphorylation and processing of NF-κB2 (p100) to produce p52, which translocates to the nucleus (9-11).

$111
20 µl
$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Immunoprecipitation, Western Blotting

Background: Bak is a proapoptotic member of the Bcl-2 family (1). This protein is located on the outer membrane of mitochondria and is an essential component for transduction of apoptotic signals through the mitochondrial pathway (2,3). Upon apoptotic stimulation, an upstream stimulator like truncated BID (tBID) induces conformational changes in Bak to form oligomer channels in the mitochondrial membrane for cytochrome c release. The release of cytochrome c to the cytosol activates the caspase-9 pathway and eventually leads to cell death (4,5).

$111
20 µl
$260
100 µl
APPLICATIONS
REACTIVITY
Human

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).

$115
100 µl
This Cell Signaling Technology antibody is conjugated to phycoerythrin (PE) and tested in-house for direct flow cytometry analysis in human cells.
APPLICATIONS

Application Methods: Flow Cytometry

Background: Isotype control antibodies are used to estimate the nonspecific binding of target primary antibodies due to Fc receptor binding or other protein-protein interactions. An isotype control antibody should have the same immunoglobulin type and be used at the same concentration as the test antibody.

$118
10 western blots
200 µl
Nonphosporylated MEK1/2 Control Cell Extracts: Total cell extracts from HeLa cells, serum starved overnight serve as a negative control. Supplied in SDS Sample Buffer.Phosphorylated MEK1/2 Control Cell Extracts: Total cell extracts from HeLa cells, serum starved overnight then treated with 200 nM TPA #4174 for 15 minutes to serve as a positive control. Supplied in SDS Sample Buffer.
APPLICATIONS

Application Methods: Western Blotting

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

The Insulin/IGF-1 Signaling Pathway Antibody Sampler Kit provides an economical means of detecting select components involved in the insulin and/or IGF-1 signaling pathways. The kit contains enough primary antibodies to perform at least two western blot experiments per antibody.

Background: Insulin and IGF-1 act on two closely related tyrosine kinase receptors to initiate a cascade of signaling events. These signaling events activate a variety of biological molecules, including kinases and transcription factors, which regulate cell growth, survival and metabolism.Type I insulin-like growth factor receptor (IGF-IR) is a transmembrane receptor tyrosine kinase that is widely expressed in many cell lines and cell types within fetal and postnatal tissues (1-3). Three tyrosine residues within the kinase domain (Tyr1131, Tyr1135, and Tyr1136) are the earliest major autophosphorylation sites (4). Phosphorylation of these three tyrosine residues is necessary for kinase activation (5,6). Insulin receptors (IRs) share significant structural and functional similarity with IGF-I receptors, including the presence of an equivalent tyrosine cluster (Tyr1146/1150/1151) within the kinase domain activation loop. Tyrosine autophosphorylation of IRs is one of the earliest cellular responses to insulin stimulation (7). Autophosphorylation begins with phosphorylation at Tyr1146 and either Tyr1150 or Tyr1151, while full kinase activation requires triple tyrosine phosphorylation (8).Akt, also referred to as PKB or Rac, plays a critical role in controlling survival and apoptosis (9-11). This protein kinase is activated by insulin and various growth and survival factors to function in a wortmannin-sensitive pathway involving PI3 kinase (10,11). Akt is activated by phospholipid binding and activation loop phosphorylation at Thr308 by PDK1 (12) 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 (13,14).Tuberin is a product of the TSC2 tumor suppressor gene and an important regulator of cell proliferation and tumor development (15). Tuberin is phosphorylated on Ser939 and Thr1462 in response to PI3K activation and the human TSC complex is a direct biochemical target of the PI3K/Akt pathway (16). This result complements Drosophila genetics studies suggesting the possible involvement of the tuberin-hamartin complex in the PI3K/Akt mediated insulin pathway (17-19).The mammalian target of rapamycin (mTOR, FRAP, RAFT) is a Ser/Thr protein kinase (20-22) that functions as an ATP and amino acid sensor to balance nutrient availability and cell growth (23,24). When sufficient nutrients are available, mTOR responds to a phosphatidic acid-mediated signal to transmit a positive signal to p70 S6 kinase and participate in the inactivation of the eIF4E inhibitor, 4E-BP1 (25). These events result in the translation of specific mRNA subpopulations. mTOR is phosphorylated at Ser2448 via the PI3 kinase/Akt signaling pathway and autophosphorylated at Ser2481 (26,27).The Forkhead family of transcription factors is involved in tumorigenesis of rhabdomyosarcoma and acute leukemias (28-30). 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 (31-33). Active forkhead members act as tumor suppressors by promoting cell cycle arrest and apoptosis. 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 (34).Glycogen synthase kinase-3 (GSK-3) was initially identified as an enzyme that regulates glycogen synthesis in response to insulin (35). 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 (36,37).

PhosphoPlus® Duets from Cell Signaling Technology (CST) provide a means to assess protein activation status. Each Duet contains an activation-state and total protein antibody to your target of interest. These antibodies have been selected from CST's product offering based upon superior performance in specified applications.

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

The Src Family Antibody Sampler Kit provides an economical means of evaluating total levels of Src family member proteins. The kit contains enough primary and secondary antibody to perform two western blots with each antibody.

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).