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Product listing: Pan-Actin (D18C11) Rabbit mAb, UniProt ID P60709 #8456 to Rig-I Pathway Antibody Sampler Kit #8348

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

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

Background: Actin, a ubiquitous eukaryotic protein, is the major component of the cytoskeleton. At least six isoforms are known in mammals. Nonmuscle β- and γ-actin, also known as cytoplasmic actin, are predominantly expressed in nonmuscle cells, controlling cell structure and motility (1). α-cardiac and α-skeletal actin are expressed in striated cardiac and skeletal muscles, respectively; two smooth muscle actins, α- and γ-actin, are found primarily in vascular smooth muscle and enteric smooth muscle, respectively. These actin isoforms regulate the contractile potential of muscle cells (1). Actin exists mainly as a fibrous polymer, F-actin. In response to cytoskeletal reorganizing signals during processes such as cytokinesis, endocytosis, or stress, cofilin promotes fragmentation and depolymerization of F-actin, resulting in an increase in the monomeric globular form, G-actin (2). The ARP2/3 complex stabilizes F-actin fragments and promotes formation of new actin filaments (2). Research studies have shown that actin is hyperphosphorylated in primary breast tumors (3). Cleavage of actin under apoptotic conditions has been observed in vitro and in cardiac and skeletal muscle, as shown in research studies (4-6). Actin cleavage by caspase-3 may accelerate ubiquitin/proteasome-dependent muscle proteolysis (6).

$293
100 µl
APPLICATIONS
REACTIVITY
Human

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

Background: IFN-γ plays key roles in both the innate and adaptive immune response. IFN-γ activates the cytotoxic activity of innate immune cells, such as macrophages and NK cells (1,2). IFN-γ production by NK cells and antigen presenting cells (APCs) promotes cell-mediated adaptive immunity by inducing IFN-γ production by T lymphocytes, increasing class I and class II MHC expression, and enhancing peptide antigen presentation (1). The anti-viral activity of IFN-γ is due to its induction of PKR and other regulatory proteins. Binding of IFN-γ to the IFNGR1/IFNGR2 complex promotes dimerization of the receptor complexes to form the (IFNGR1/IFNGR2)2 -IFN-γ dimer. Binding induces a conformational change in receptor intracellular domains and signaling involves Jak1, Jak2, and Stat1 (3). The critical role of IFN-γ in amplification of immune surveillance and function is supported by increased susceptibility to pathogen infection by IFN-γ or IFNGR knockout mice and in humans with inactivating mutations in IFNGR1 or IFNGR2. IFN-γ also appears to have a role in atherosclerosis (4).

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

Application Methods: Immunoprecipitation, Western Blotting

Background: Glycogen synthase kinase-3 (GSK-3) was initially identified as an enzyme that regulates glycogen synthesis in response to insulin (1). GSK-3 is a ubiquitously expressed serine/threonine protein kinase that phosphorylates and inactivates glycogen synthase. GSK-3 is a critical downstream element of the PI3K/Akt cell survival pathway whose activity can be inhibited by Akt-mediated phosphorylation at Ser21 of GSK-3α and Ser9 of GSK-3β (2,3). GSK-3 has been implicated in the regulation of cell fate in Dictyostelium and is a component of the Wnt signaling pathway required for Drosophila, Xenopus, and mammalian development (4). GSK-3 has been shown to regulate cyclin D1 proteolysis and subcellular localization (5).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: Phosphatidylinositol lipids and phosphoinositides are important second messengers, their generation controlling many cellular events. Intracellular levels of these molecules are regulated by phosphoinositide kinases and phosphatases. One of the best characterized lipid kinases is phosphoinositide 3-kinase (PI3K), which is responsible for phosphorylation on the D-3 position of the inositide head group (1). This action of PI3K catalyzes the production of phosphatidylinositol-3,4,5-triphosphate by phosphorylating phosphatidylinositol (PI), phosphatidylinositol-4-phosphate (PIP), and phosphatidylinositol-4,5-bisphosphate (PIP2). Growth factors and hormones trigger this phosphorylation event, which in turn coordinates cell growth, cell cycle entry, cell migration, and cell survival (1). PTEN, the well characterized partnering phosphatase, reverses this process by removing the phosphate from PI(3,4,5)P3 at the D-3 position to generate PI(4,5)P2 (1,2). Dephosphorylation on the D-5 position to generate PI(3,4)P2 occurs through the action of SHIP1 or SHIP2 (3), and dephosphorylation on the D-4 position to generate PI(3)P can occur through the action of inositol polyphosphate 4-phosphatase isoenzymes type I (INPP4a) and type II (INPP4b) (4,5). While INPP4a has been implicated in neuronal survival and megakaryocyte lineage determination (6,7), less is understood about INPP4b. It has been shown that two splice variants of INPP4b occur in mice, each showing distinct tissue distribution and subcellular localization (5,8).

$122
20 µl
$293
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

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

Background: Steroidogenic acute regulatory protein (StAR) plays a significant role in cholesterol transport from the cytoplasmic outer membrane to the inner mitochondrial membrane (1). The 37 kDa precursor is cleaved to generate an active 28 kDa protein capable of facilitating cholesterol metabolism into pregnenolone (2,3). StAR is prevalently expressed in mitochondria of steroid-producing adrenal and gonadal tissue (3). Abnormalities in StAR gene expression are impacted in autosomal Lipoid Congenial Adrenal Hyperplasia (LCAH) resulting in defects in pregnenolone and cortisol synthesis (4). The mechanism of cholesterol binding to StAR has yet to be elucidated (4).

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

Application Methods: Immunoprecipitation, Western Blotting

Background: The c-Cbl proto-oncogene is a ubiquitously expressed cytoplasmic adaptor protein that is especially predominant in hematopoietic cells (1,2). c-Cbl is rapidly tyrosine-phosphorylated in response to stimulation of a variety of cell-surface receptors and becomes associated with a number of intracellular signaling molecules such as protein tyrosine kinases, phosphatidylinositol-3 kinase, Crk, and 14-3-3 proteins (3,4). c-Cbl possesses a highly conserved amino-terminal phosphotyrosine binding domain (TKB) and a C3HC4 RING finger motif. The TKB recognizes phosphorylated tyrosines on activated receptor tyrosine kinases (RTKs) as well as other nonreceptor tyrosine kinases. The RING finger motif recruits ubiquitin-conjugating enzymes. These two domains are primarily responsible for the ubiquitin ligase activity of c-Cbl and downregulation of RTKs (3). Research studies have indicated that in human cancer tissues, c-Cbl is frequently tyrosine-phosphorylated in a tumor-specific manner (5). Phosphorylation of Tyr731 of c-Cbl provides a docking site for downstream signaling components such as p85 and Fyn (6).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Immunoprecipitation, Western Blotting

Background: R-Ras, a member of the small GTPase family, is homologous to H-, K- and N-Ras, but does not activate MAP kinase pathways and is only weakly oncogenic (1). Instead, R-Ras is engaged in integrin activation (2). The effector loop and the carboxy-terminal proline-rich and prenylation sites of R-Ras are critical for integrin activation (3,4). Phosphorylation by EphB2 receptor tyrosine kinase and Src at Tyr66 of R-Ras suppresses integrin activity (5,6).

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

Application Methods: Western Blotting

Background: HSPA8, alternately known as HSC70 or HSP73, is a constitutively expressed member of the HSP70 superfamily (1). Although its primary role in cells appears to be that of a general chaperone for unfolded proteins, HSPA8 has also been identified as the uncoating ATPase responsible for removing clathrin from coated vesicles and may also play a role in stabilizing untranslated mRNAs (1-5). In addition to these "housekeeping" functions, HSPA8 may also have an important role in inducible cellular stress responses. For example, oxidative or thermal stress promotes the nuclear/nucleolar accumulation of HSPA8, where it forms a complex with the topoisomerase I complex and likely protects it from heat inactivation (6,7). HSPA8 is reportedly phosphorylated in response to DNA damage, but it remains unclear what effect, if any, this has on HSPA8 function (8-10). Numerous high throughput studies support this observation. For more information, please see the HSPA8 page in PhosphoSitePlus® at www.phosphosite.org.

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

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

Background: Heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) 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). hnRNP A1 regulates the alternative splicing of c-Src and c-H-Ras (2,3) and modifies initiation of translation of the fibroblast growth factor 2 mRNA (4). hnRNP A1 expression level is elevated in many cancers; knockdown of hnRNP A1 leads to apoptosis in various cancer cells (5). Although predominantly nuclear, hnRNP A1 is continually transported from the nucleus to the cytoplasm where it disassociates from mRNA and is rapidly re-imported into the nucleus (6,7). hnRNP A1 binds to cis-acting repressive sequences (CRS) of HIV-1 to influence HIV-1 production (8,9). HIV-1 enhances hnRNP A1 expression and promotes the relocalization of hnRNP A1 to the cytoplasm (10).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Western Blotting

Background: SLC1A4, also known as ASCT1, is a neutral amino acid transporter. Its other name, ASCT1, was given because it mediates obligatory exchange of alanine, serine, cysteine, and threonine (1). SLC1A4 mediates the efflux of glutamate from the neuron into the synaptic junction via calcium-independent release, as well as mediating the efflux of L-serine from glial cells and its uptake by neurons (2). SLC1A4-mediated transport is shown to involve a symmetrical potassium-independent electroneutral exchange of neutral amino acids and sodium, such that the current activated during transport is carried only by chloride ions (3).

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

Application Methods: Western Blotting

Background: Translationally controlled tumor protein (TCTP/p23/HRF) is a ubiquitously expressed and highly conserved protein involved in various cellular processes, such as its role as a histamine releasing factor in chronic allergic disease (1). TCTP binds tubulin in a cell cycle dependent manner and is associated with the mitotic spindle (2). In addition, TCTP interacts with the actin cytoskeleton to regulate cell shape (3). In mitosis, TCTP is phosphorylated by PLK at Ser46, decreasing microtubule stability (4,5). TCTP interacts with the small GTPase Rheb, possibly acting as a GEF, thereby activating the TORC1 pathway and controlling cell growth and proliferation (6,7). TCTP has also been shown to be involved in apoptosis and cell stress (8-11). In cultured cells, reduction in TCTP expression can cause loss of the malignant phenotype (12).

$122
20 µl
$293
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

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

Background: Integrins are α/β heterodimeric cell surface receptors that play a pivotal role in cell adhesion and migration, as well as in growth and survival (1,2). The integrin family contains at least 18 α and 8 β subunits that form 24 known integrins with distinct tissue distribution and overlapping ligand specificities (3). Integrins not only transmit signals to cells in response to the extracellular environment (outside-in signaling), but also sense intracellular cues to alter their interaction with the extracellular environment (inside-out signaling) (1,2).A pair of important α4 integrins, α4β1 and α4β7, interact with VCAM-1, fibronectin, and MAdCAM-1 at cell adhesions (3). Gene knockout and antibody blocking research reveal that α4 integrins play important roles in embryonic liver and heart development and in fetal lymphocyte homing (4-6). Phosphorylation at Ser988 within the cytoplasmic tail of integrin α4 blocks binding to paxillin and promotes leading edge migration (7,8).On SDS-PAGE, integrin α4 can migrate at several different apparent molecular sizes, a 150 kDa mature protein and a 140 kDa precursor protein (a 180 kDa protein also exists under mild non-reducing conditions) (9). Integrin α4 has a cleavage site at Arg558, which results in a small portion of the protein as either an 80 kDa N-terminal or 70 kDa C-terminal fragment (10).

$122
20 µl
$303
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

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

Background: Caspase-7 (CMH-1, Mch3, ICE-LAP3) has been identified as a major contributor to the execution of apoptosis (1-4). Caspase-7, like caspase-3, is an effector caspase that is responsible for cleaving downstream substrates such as (ADP-ribose) polymerase and PARP (1,3). During apoptosis, caspase-7 is activated through proteolytic processing by upstream caspases at Asp23, Asp198, and Asp206 to produce the mature subunits (1,3). Similar to caspase-2 and -3, caspase-7 preferentially cleaves substrates following the recognition sequence DEVD (5).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: The suppressor of cytokine signaling (SOCS) family members are negative regulators of cytokine signal transduction that inhibit the Jak/Stat pathway (1-3). The SOCS family consists of at least 8 members including the originally identified cytokine-inducible SH2-containing protein (CIS1), as well as SOCS1-7. Each SOCS family member contains a central SH2 domain and a conserved carboxy-terminal motif designated as the SOCS box. These proteins are important regulators of cytokine signaling, proliferation, differentiation, and immune responses.

$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 Androgen Receptor (D6F11) XP® Rabbit mAb #5153.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry

Background: Androgen receptor (AR), a zinc finger transcription factor belonging to the nuclear receptor superfamily, is activated by phosphorylation and dimerization upon ligand binding (1). This promotes nuclear localization and binding of AR to androgen response elements in androgen target genes. Research studies have shown that AR plays a crucial role in several stages of male development and the progression of prostate cancer (2,3).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse

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

Background: YAP (Yes-associated protein, YAP65) was identified based on its ability to associate with the SH3 domain of Yes. It also binds to other SH3 domain-containing proteins such as Nck, Crk, Src, and Abl (1). In addition to the SH3 binding motif, YAP contains a PDZ interaction motif, a coiled-coil domain, and WW domains (2-4). While initial studies of YAP all pointed towards a role in anchoring and targeting to specific subcellular compartments, subsequent studies showed that YAP is a transcriptional co-activator by virtue of its WW domain interacting with the PY motif (PPxY) of the transcription factor PEBP2 and other transcription factors (5). In its capacity as a transcriptional co-activator, YAP is now widely recognized as a central mediator of the Hippo Pathway, which plays a fundamental and widely conserved role in regulating tissue growth and organ size. Phosphorylation at multiple sites (e.g., Ser109, Ser127) by LATS kinases promotes YAP translocation from the nucleus to the cytoplasm, where it is sequestered through association with 14-3-3 proteins (6-8). These LATS-driven phosphorylation events serve to prime YAP for subsequent phosphorylation by CK1δ/ε in an adjacent phosphodegron, triggering proteosomal degradation of YAP (9).

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

Application Methods: Immunoprecipitation, Western Blotting

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

$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: DNA damage, if not repaired, can lead to genome instability and tumorigenesis. Eukaryotic cells use multiple (sometimes overlapping) signaling pathways to respond to agents that cause various types of DNA lesions. Downstream molecules in DNA repair pathways converge on the sites of DNA damage, resulting in cell cycle arrest and repair or apoptosis (1). Rad18 is an E3 ubiquitin ligase recruited to sites of DNA damage. Along with the E2 ubiquitin ligase Rad6, Rad18 is responsible for monoubiquitination of DNA damage proteins including the replication clamp PCNA and the Fanconi anemia core protein FANCD2. Monoubiquitination of these proteins signals to downstream effector molecules and results in the repair of either post-replication repair lesions via the translesion synthesis (TLS) pathway or DNA double strand breaks via homologous recombination (2-4). Phospho-proteomic studies indicate that Ser403 of Rad18 may be phosphorylated by ATM/ATR in response to DNA damage-inducing agents (5,6).

The ULK1 Antibody Sampler Kit provides an economical way to investigate ULK1 signaling. The kit contains enough primary antibody to perform two western blots with each primary antibody.

Background: Two related serine/threonine kinases, UNC-51-like kinase 1 and 2 (ULK1, ULK2), were discovered as mammalian homologs of the C. elegans gene UNC-51 in which mutants exhibited abnormal axonal extension and growth (1-4). Both proteins are widely expressed and contain an amino-terminal kinase domain followed by a central proline/serine rich domain and a highly conserved carboxy-terminal domain. The roles of ULK1 and ULK2 in axon growth have been linked to studies showing that the kinases are localized to neuronal growth cones and are involved in endocytosis of critical growth factors, such as NGF (5). Yeast two-hybrid studies found ULK1/2 associated with modulators of the endocytic pathway, SynGAP and syntenin (6). Structural similarity of ULK1/2 has also been recognized with the yeast autophagy protein Atg1/Apg1 (7). Knockdown experiments using siRNA demonstrated that ULK1 is essential for autophagy (8), a catabolic process for the degradation of bulk cytoplasmic contents (9,10). It appears that Atg1/ULK1 can act as a convergence point for multiple signals that control autophagy (11), and can bind to several autophagy-related (Atg) proteins, regulating phosphorylation states and protein trafficking (12-16).

This sampler kit provides an economical means of evaluating key members of the Hedgehog signaling pathway. The kit contains enough primary and secondary antibody to perform two western miniblot experiments.
The Stress and Apoptosis Antibody Sampler Kit provides an economical means of evaluating stress and apoptotic responses of each protein. The kit contains enough primary and secondary antibody to perform two western blot experiments per primary antibody.
The Death Receptor Antibody Sampler Kit provides an economical means to investigate the machinery of death receptor-mediated apoptosis. The kit includes enough of each primary antibody to perform two western mini-blot experiments per primary.
The Cofilin Activation Antibody Sampler Kit provides an economical means to evaluate the presence and status of cofilin activation. The kit contains enough primary antibody to perform two western blot experiments per antibody.

Background: Cofilin and actin-depolymerization factor (ADF) are members of a family of essential conserved small actin-binding proteins that play pivotal roles in cytokinesis, endocytosis, embryonic development, stress response, and tissue regeneration (1). In response to stimuli, cofilin promotes the regeneration of actin filaments by severing preexisting filaments (2). The severing activity of cofilin is inhibited by LIMK or TESK phosphorylation at Ser3 of cofilin (3-5). Phosphorylation at Ser3 also regulates cofilin translocation from the nucleus to the cytoplasm (6).

The DUB Antibody Sampler Kit offers an economical means of evaluating the presence and status of selected DUB enzymes. This kit contains enough primary antibody to perform two western blot experiments per primary.
$260
100 µl
APPLICATIONS
REACTIVITY
Human

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

Background: The electroneutral cation-chloride-coupled co-transporter (SLC12) gene family comprises bumetanide-sensitive Na+/K+/Cl- (NKCC), thiazide-sensitive Na+/Cl-, and K+/Cl- (KCC) co-transporters. SLC12A1/NKCC2 and SLC12A2/NKCC1 regulate cell volume and maintain cellular homeostasis in response to osmotic and oxidative stress (1). The broadly expressed NKCC1 is thought to play roles in fluid secretion (i.e. salivary gland function), salt balance (i.e. maintenance of renin and aldosterone levels), and neuronal development and signaling (2-7). During neuronal development, NKCC1 and KCC2 maintain a fine balance between chloride influx (NKCC1) and efflux (KCC2), which regulates γ-aminobutyric acid (GABA)-mediated neurotransmission (3). Increased NKCC1 expression in immature neurons maintains high intracellular chloride levels that result in inhibitory GABAergic signaling; KCC2 maintains low intracellular chloride levels and excitatory GABAergic responses in mature neurons (4,5,8). Deletion of NKCC1 impairs NGF-mediated neurite outgrowth in PC-12D cells while inhibition of NKCC1 with bumetanide inhibits re-growth of axotomized dorsal root ganglion cells (6,7). Defective chloride homeostasis in neurons is linked to seizure disorders that are ameliorated by butemanide treatment, indicating that abnormal NKCC1 and NKCC2 expression or signaling may play a role in neonatal and adult seizures (9-12). NKCC1 is found as a homodimer or within heterooligomers with other SLC12 family members. This transport protein associates with a number of oxidative- and osmotic-responsive kinases that bind, phosphorylate, and activate NKCC1 co-transporter activity (13-16). In response to decreased intracellular chloride concentrations, Ste20-related proline-alanine-rich kinase (SPAK) phosphorylates NKCC1 to increase co-transporter activity and promote chloride influx (16-19). Oxidative stress response kinase 1 (OSR1) also phosphorylates and activates NKCC1 in response to oxidative stress (14).

The Phospho-TSC2 Antibody Sampler Kit provides an economical means to investigate protein folding within the cell. The kit contains enough primary and secondary antibodies to perform two western blot experiments per primary antibody.

Background: Tuberin is a product of the TSC2 tumor suppressor gene and an important regulator of cell proliferation and tumor development (1). Mutations in either TSC2 or the related TSC1 (hamartin) gene cause tuberous sclerosis complex (TSC), an autosomal dominant disorder characterized by development of multiple, widespread non-malignant tumors (2). Tuberin is directly phosphorylated at Thr1462 by Akt/PKB (3). Phosphorylation at Thr1462 and Tyr1571 regulates tuberin-hamartin complexes and tuberin activity (3-5). In addition, tuberin inhibits the mammalian target of rapamycin (mTOR), which promotes inhibition of p70 S6 kinase, activation of eukaryotic initiation factor 4E binding protein 1 (4E-BP1, an inhibitor of translation initiation), and eventual inhibition of translation (3,6,7).

NuRD Complex Antibody Sampler Kit offers an economical means of detecting each target protein that composes the nucleosome remodeling and deacetylation complex (NuRD). The kit contains enough primary antibody to perform two western blot experiments with each primary antibody.
The Rig-I Pathway Antibody Sampler Kit provides an economical means to evaluate the activation state and total protein levels of multiple members of the Rig-I pathway including Rig-I, MDA-5, MAVS, IRF-3, TBK1/NAK, and IKKε. The kit includes enough primary antibody to perform two western blot experiments per antibody.

Background: Antiviral innate immunity depends on the combination of parallel pathways triggered by virus detecting proteins in the Toll-like receptor (TLR) family and RNA helicases, such as Rig-I (retinoic acid-inducible gene I) and MDA-5 (melanoma differentiation-associated antigen 5), which promote the transcription of type I interferons (IFN) and antiviral enzymes (1-3). TLRs and helicase proteins contain sites that recognize the molecular patterns of different virus types, including DNA, single-stranded RNA (ssRNA), double-stranded RNA (dsRNA), and glycoproteins. These antiviral proteins are found in different cell compartments; TLRs (i.e. TLR3, TLR7, TLR8, and TLR9) are expressed on endosomal membranes and helicases are localized to the cytoplasm. Rig-I expression is induced by retinoic acid, LPS, IFN, and viral infection (4,5). Both Rig-I and MDA-5 share a DExD/H-box helicase domain that detects viral dsRNA and two amino-terminal caspase recruitment domains (CARD) that are required for triggering downstream signaling (4-7). Rig-I binds both dsRNA and viral ssRNA that contains a 5'-triphosphate end not seen in host RNA (8,9). Though structurally related, Rig-I and MDA-5 detect a distinct set of viruses (10,11). The CARD domain of the helicases, which is sufficient to generate signaling and IFN production, is recruited to the CARD domain of the MAVS/VISA/Cardif/IPS-1 mitochondrial protein, which triggers activation of NF-κB, TBK1/IKKε, and IRF-3/IRF-7 (12-15).