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Human DNA Ligase Activity

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: DNA double-strand breaks (DSBs) are potentially hazardous lesions that can be induced by ionizing radiation (IR), radiomimetic chemicals, or DNA replication inhibitors. Cells detect and repair DSBs through two distinct but partly overlapping signaling pathways, nonhomologous end joining (NHEJ) and homologous recombination (HR). DNA repair through the HR pathway is restricted to S and G2 phases of the cell cycle, while NHEJ can occur during any cell cycle phase. Defects in both pathways have been associated with human disease, including cancer (1).DNA repair through the NHEJ pathway involves a core group of proteins that includes the Ku heterodimer, DNA-PKcs, DNA ligase IV, XRCC4, and XLF. XLF interacts with XRCC4 and promotes the ligation of DNA strands by DNA ligase IV and the ligase cofactor XRCC4. The ATP-dependent ligation of free DNA ends is the final step in the NHEJ repair pathway (2). Research studies suggest that XLF and XRCC4 proteins form complexes that bridge DNA breaks earlier in the NHEJ pathway (3). Additional studies indicate that localization of XRCC4 to the nucleus and levels of XRCC4 protein are both regulated by DNA ligase IV (4). Mutations in the corresponding LIG4 gene are associated with LIG4 syndrome, a disorder characterized by immunodeficiency and developmental growth delay. Cells isolated from patients diagnosed with LIG4 syndrome display typical cell cycle checkpoint activity, but aberrant rejoining of DNA double strand breaks (5,6).

$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).

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

Application Methods: Western Blotting

Background: The HECT domain-containing ubiquitin E3 ligase HECTH9 (also known as HUWE1, ARF-BP1, URE-B1, Mule, and LASU1) is critical for the ubiquitination and proteasomal degradation of many target proteins, and is involved in the regulation of a variety of cellular processes, including DNA replication and base excision repair, cellular proliferation, differentiation, and apoptosis. HECTH9 contains two Armadillo (ARM) repeat-like domains (ARLD1 and ARLD2), a ubiquitin-associated (UBA) domain, a WWE domain, a well-conserved BH3 domain, and a catalytic HECT domain that facilitates ubiquitination of target proteins. HECTH9 has been shown to polyubiquitinate p53 (1,2), Miz1 (3), N-Myc (4,5), Mcl-1 (6), Cdc 6 (7), and DNA polymerase beta (8) through K48-mediated linkage, thereby targeting these proteins for proteosomal degradation. The tumor suppressor protein ARF (known as p14 ARF in humans and p19 ARF in mice) binds to and inhibits the uibiquitin ligase activity toward p53, resulting in stabilization of p53 and induction of apoptosis (1). HECTH9 has also been shown to polyubiquitinate c-Myc through K63-linkage, which is required for recruitment of p300, activation of c-Myc target genes, and induction of cellular proliferation (9). HECTH9 is overexpressed in colon, lung, and breast cancer (1,9). In addition, defects in HECTH9 result in mental retardation syndromic X-linked Turner type (MRXST) and mental retardation X-linked type 17 (MRX17) syndromes (10).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: The transcriptional intermediary factor 1 (TIF1) family represents a group of proteins with multiple histone-binding domains. In humans, this family comprises four proteins, TIF1α/TRIM24, TIF1β/TRIM28/KAP1, TIF1γ/TRIM33/Ectodermin, and TIF1δ/TRIM66, which are characterized by an amino-terminal tripartite motif (TRIM) domain consisting of a RING domain, two B boxes, a coiled-coil domain, and a carboxy-terminal PHD finger and bromodomain (1). Despite their similar overall structure, these proteins have diverse roles in transcriptional regulation. TIF1α functions as a ligand-dependent nuclear receptor coregulator and more recently has been implicated in regulating p53 stability (2). TIF1β is an intrinsic component of the N-CoR1 corepressor complex and the NuRD nucleosome-remodeling complex (3) and functions as a corepressor for Kruppel-associated box (KRAB) zinc-finger transcription factors (4). Furthermore, TIF1β promotes heterochromatin-mediated gene silencing formation by serving as a cofactor for heterochromatin protein HP1 (5). TIF1δ expression is restricted to the testis and has been shown to interact with HP1γ (6).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Chromatin IP, Flow Cytometry, Immunohistochemistry (Paraffin), Immunoprecipitation, Western Blotting

Background: The transcriptional intermediary factor 1 (TIF1) family represents a group of proteins with multiple histone-binding domains. In humans, this family comprises four proteins, TIF1α/TRIM24, TIF1β/TRIM28/KAP1, TIF1γ/TRIM33/Ectodermin, and TIF1δ/TRIM66, which are characterized by an amino-terminal tripartite motif (TRIM) domain consisting of a RING domain, two B boxes, a coiled-coil domain, and a carboxy-terminal PHD finger and bromodomain (1). Despite their similar overall structure, these proteins have diverse roles in transcriptional regulation. TIF1α functions as a ligand-dependent nuclear receptor coregulator and more recently has been implicated in regulating p53 stability (2). TIF1β is an intrinsic component of the N-CoR1 corepressor complex and the NuRD nucleosome-remodeling complex (3) and functions as a corepressor for Kruppel-associated box (KRAB) zinc-finger transcription factors (4). Furthermore, TIF1β promotes heterochromatin-mediated gene silencing formation by serving as a cofactor for heterochromatin protein HP1 (5). TIF1δ expression is restricted to the testis and has been shown to interact with HP1γ (6).

$111
20 µl
$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: The breast cancer susceptibility proteins BRCA1 and BRCA2 are frequently mutated in cases of hereditary breast and ovarian cancers and have roles in multiple processes related to DNA damage, repair, cell cycle progression, transcription, ubiquitination, and apoptosis (1-4). BRCA2 has been shown to be required for localization of Rad51 to sites of double stranded breaks (DSBs) in DNA, and cells lacking BRCA1 and BRCA2 cannot repair DSBs through the Rad51-dependent process of homologous recombination (HR) (5). Numerous DNA damage-induced phosphorylation sites on BRCA1 have been identified, including Ser988, 1189, 1387, 1423, 1457, 1524, and 1542, and kinases activated in a cell cycle-dependent manner, including Aurora A and CDK2, can also phosphorylate BRCA1 at Ser308 and Ser1497, respectively (6-10). Cell cycle-dependent phosphorylation of BRCA2 at Ser3291 by CDKs has been proposed as a mechanism to switch off HR as cells progress beyond S-phase by blocking the carboxy terminal Rad51 binding site (11).

$122
20 µl
$293
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunofluorescence (Immunocytochemistry), 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).

$262
3 nmol
300 µl
SignalSilence® BRCA1 siRNA I from Cell Signaling Technology (CST) allows the researcher to specifically inhibit BRCA1 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: The breast cancer susceptibility proteins BRCA1 and BRCA2 are frequently mutated in cases of hereditary breast and ovarian cancers and have roles in multiple processes related to DNA damage, repair, cell cycle progression, transcription, ubiquitination, and apoptosis (1-4). BRCA2 has been shown to be required for localization of Rad51 to sites of double stranded breaks (DSBs) in DNA, and cells lacking BRCA1 and BRCA2 cannot repair DSBs through the Rad51-dependent process of homologous recombination (HR) (5). Numerous DNA damage-induced phosphorylation sites on BRCA1 have been identified, including Ser988, 1189, 1387, 1423, 1457, 1524, and 1542, and kinases activated in a cell cycle-dependent manner, including Aurora A and CDK2, can also phosphorylate BRCA1 at Ser308 and Ser1497, respectively (6-10). Cell cycle-dependent phosphorylation of BRCA2 at Ser3291 by CDKs has been proposed as a mechanism to switch off HR as cells progress beyond S-phase by blocking the carboxy terminal Rad51 binding site (11).

$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).

$122
20 µl
$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: The breast cancer susceptibility proteins BRCA1 and BRCA2 are frequently mutated in cases of hereditary breast and ovarian cancers and have roles in multiple processes related to DNA damage, repair, cell cycle progression, transcription, ubiquitination, and apoptosis (1-4). BRCA2 has been shown to be required for localization of Rad51 to sites of double stranded breaks (DSBs) in DNA, and cells lacking BRCA1 and BRCA2 cannot repair DSBs through the Rad51-dependent process of homologous recombination (HR) (5). Numerous DNA damage-induced phosphorylation sites on BRCA1 have been identified, including Ser988, 1189, 1387, 1423, 1457, 1524, and 1542, and kinases activated in a cell cycle-dependent manner, including Aurora A and CDK2, can also phosphorylate BRCA1 at Ser308 and Ser1497, respectively (6-10). Cell cycle-dependent phosphorylation of BRCA2 at Ser3291 by CDKs has been proposed as a mechanism to switch off HR as cells progress beyond S-phase by blocking the carboxy terminal Rad51 binding site (11).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: The breast cancer susceptibility proteins BRCA1 and BRCA2 are frequently mutated in cases of hereditary breast and ovarian cancers and have roles in multiple processes related to DNA damage, repair, cell cycle progression, transcription, ubiquitination, and apoptosis (1-4). BRCA2 has been shown to be required for localization of Rad51 to sites of double stranded breaks (DSBs) in DNA, and cells lacking BRCA1 and BRCA2 cannot repair DSBs through the Rad51-dependent process of homologous recombination (HR) (5). Numerous DNA damage-induced phosphorylation sites on BRCA1 have been identified, including Ser988, 1189, 1387, 1423, 1457, 1524, and 1542, and kinases activated in a cell cycle-dependent manner, including Aurora A and CDK2, can also phosphorylate BRCA1 at Ser308 and Ser1497, respectively (6-10). Cell cycle-dependent phosphorylation of BRCA2 at Ser3291 by CDKs has been proposed as a mechanism to switch off HR as cells progress beyond S-phase by blocking the carboxy terminal Rad51 binding site (11).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: Tripartite motif-containing protein 21 (TRIM21) is a cytosolic antiviral protein that is induced by interferons and acts as a cytosolic IgG receptor (1,2).  TRIM21 is an activator of the innate immune system and targets antibody bound virions to the proteasome via its E3 ubiquitin ligase activity, leading to degradation of the virions in the cytosol (3,4). Interestingly, TRIM21 has also been shown to negatively regulate pathogen-induced interferon production through the polyubiquitin-mediated degradation of multiple targets including IRF3, IRF7, and DDX41 (5,6,7).

$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 TRIM33 (D7U4F) Rabbit mAb #90051.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry

Background: The transcriptional intermediary factor 1 (TIF1) family represents a group of proteins with multiple histone-binding domains. In humans, this family comprises four proteins, TIF1α/TRIM24, TIF1β/TRIM28/KAP1, TIF1γ/TRIM33/Ectodermin, and TIF1δ/TRIM66, which are characterized by an amino-terminal tripartite motif (TRIM) domain consisting of a RING domain, two B boxes, a coiled-coil domain, and a carboxy-terminal PHD finger and bromodomain (1). Despite their similar overall structure, these proteins have diverse roles in transcriptional regulation. TIF1α functions as a ligand-dependent nuclear receptor coregulator and more recently has been implicated in regulating p53 stability (2). TIF1β is an intrinsic component of the N-CoR1 corepressor complex and the NuRD nucleosome-remodeling complex (3) and functions as a corepressor for Kruppel-associated box (KRAB) zinc-finger transcription factors (4). Furthermore, TIF1β promotes heterochromatin-mediated gene silencing formation by serving as a cofactor for heterochromatin protein HP1 (5). TIF1δ expression is restricted to the testis and has been shown to interact with HP1γ (6).

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

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

Background: TIF1β is a member of the TIF1 (transcriptional intermediary factor 1) family, a group of transcriptional regulators that play key roles in development and differentiation. Members of this family are characterized by the presence of two conserved motifs – an N-terminal RING-B box-coiled-coil motif and a C-terminal PHD finger and bromodomain unit (1,2). TIF1β is a corepressor for KRAB (Kruppel associated box) domain containing zinc finger proteins. The KRAB domain containing zinc finger proteins are a large group of transcription factors that are vertebrate-specific, varied in their expression patterns between species, and thought to regulate gene transcription programs that control speciation (3,4).TIF1β has been shown to be essential for early embryonic development and spermatogenesis (6,5). It functions to either activate or repress transcription in response to environmental or developmental signals by chromatin remodeling and histone modification. The recruitment and association of TIF1β with heterochromatin protein (HP1) is essential for transcriptional repression, and for progression through differentiation of F9 embryonic carcinoma cells (6,7). TIF1β also plays a role in the DNA damage response. Phosphorylation of TIF1β on Ser842 occurs in an ATM-dependent manner in response to genotoxic stress and is thought to be essential for chromatin relaxation, which is in turn required for the DNA damage response (8).

$122
20 µl
$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: TIF1β is a member of the TIF1 (transcriptional intermediary factor 1) family, a group of transcriptional regulators that play key roles in development and differentiation. Members of this family are characterized by the presence of two conserved motifs – an N-terminal RING-B box-coiled-coil motif and a C-terminal PHD finger and bromodomain unit (1,2). TIF1β is a corepressor for KRAB (Kruppel associated box) domain containing zinc finger proteins. The KRAB domain containing zinc finger proteins are a large group of transcription factors that are vertebrate-specific, varied in their expression patterns between species, and thought to regulate gene transcription programs that control speciation (3,4).TIF1β has been shown to be essential for early embryonic development and spermatogenesis (6,5). It functions to either activate or repress transcription in response to environmental or developmental signals by chromatin remodeling and histone modification. The recruitment and association of TIF1β with heterochromatin protein (HP1) is essential for transcriptional repression, and for progression through differentiation of F9 embryonic carcinoma cells (6,7). TIF1β also plays a role in the DNA damage response. Phosphorylation of TIF1β on Ser842 occurs in an ATM-dependent manner in response to genotoxic stress and is thought to be essential for chromatin relaxation, which is in turn required for the DNA damage response (8).

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

Application Methods: Western Blotting

Background: The protein inhibitor of activated Stat (PIAS) proteins, which include PIAS1, PIAS3, PIASx, and PIASy, were originally characterized based on their interaction with the Stat family of transcription factors (1,2). PIAS1, PIAS3, and PIASx interact with and repress Stat1, Stat3, and Stat4, respectively (1-3). Deletion of PIAS1 leads to inhibition of interferon-inducible genes and increased protection against infection (4). The PIAS family contains a conserved RING domain that has been linked to a function as a small ubiquitin-related modifier (SUMO) ligase, coupling the SUMO conjugating enzyme Ubc9 with its substrate proteins (5,6). Numerous studies have now shown that PIAS family members can regulate the activity of transcription factors through distinct mechanisms, including NF-κB (7,8), c-Jun, p53 (5,9), Oct-4 (10), and Smads (11,12). The activity of PIAS1 is regulated by both phosphorylation and arginine methylation. Inflammatory stimuli can induce IKK-mediated phosphorylation of PIAS1 at Ser90, which is required for its activity (13). In addition, PRMT1 induces arginine methylation of PIAS1 at Arg303 following interferon treatment and is associated with its repressive activity on Stat1 (14).

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

Application Methods: Western Blotting

Background: Damaged DNA-Binding Protein (DDB) consists of a 127 kDa subunit (DDB-1) and a 48 kDa subunit (DDB-2) that contribute to the formation of the UV-damaged DNA-binding protein complex (UV-DDB) (1-3). In conjunction with CUL4A and ROC-1, the UV-DDB complex forms an E3 ubiquitin ligase that recognizes a broad spectrum of DNA lesions such as cyclobutane pyrimidine dimers, 6-4 photoproducts, apurinic sites and short mismatches. The complex polyubiquitinates components of the nucleotide excision repair pathway (4-6). Loss of DDB activity has been identified in a subset of xeroderma pigmentosum complementation group E (XP-E) patients and has been linked to the deficient repair of cyclobutane pyrimidine dimers in cells derived from these patients (7-10).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunofluorescence (Immunocytochemistry), Western Blotting

Background: TIF1β is a member of the TIF1 (transcriptional intermediary factor 1) family, a group of transcriptional regulators that play key roles in development and differentiation. Members of this family are characterized by the presence of two conserved motifs – an N-terminal RING-B box-coiled-coil motif and a C-terminal PHD finger and bromodomain unit (1,2). TIF1β is a corepressor for KRAB (Kruppel associated box) domain containing zinc finger proteins. The KRAB domain containing zinc finger proteins are a large group of transcription factors that are vertebrate-specific, varied in their expression patterns between species, and thought to regulate gene transcription programs that control speciation (3,4).TIF1β has been shown to be essential for early embryonic development and spermatogenesis (6,5). It functions to either activate or repress transcription in response to environmental or developmental signals by chromatin remodeling and histone modification. The recruitment and association of TIF1β with heterochromatin protein (HP1) is essential for transcriptional repression, and for progression through differentiation of F9 embryonic carcinoma cells (6,7). TIF1β also plays a role in the DNA damage response. Phosphorylation of TIF1β on Ser842 occurs in an ATM-dependent manner in response to genotoxic stress and is thought to be essential for chromatin relaxation, which is in turn required for the DNA damage response (8).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Western Blotting

Background: TRAFs (TNF receptor-associated factors) are a family of multifunctional adaptor proteins that bind to surface receptors and recruit additional proteins to form multiprotein signaling complexes capable of promoting cellular responses (1-3). Members of the TRAF family share a common carboxy-terminal "TRAF domain", which mediates interactions with associated proteins; many also contain amino-terminal Zinc/RING finger motifs. The first TRAFs identified, TRAF1 and TRAF2, were found by virtue of their interactions with the cytoplasmic domain of TNF-receptor 2 (TNFRII) (4). The six known TRAFs (TRAF1-6) act as adaptor proteins for a wide range of cell surface receptors and participate in the regulation of cell survival, proliferation, differentiation, and stress responses.

$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunofluorescence (Immunocytochemistry), Immunohistochemistry (Paraffin), Immunoprecipitation, 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).