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Product listing: Human Platelet-Derived Growth Factor AA (hPDGF-AA), UniProt ID P04085 #8913 to p21 Waf1/Cip1 (12D1) Rabbit mAb (PE Conjugate), UniProt ID P38936 #8865

$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 LC3B (D11) XP® Rabbit mAb #3868.
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Flow Cytometry

Background: Autophagy is a catabolic process for the autophagosomic-lysosomal degradation of bulk cytoplasmic contents (1,2). Autophagy is generally activated by conditions of nutrient deprivation, but it has also been associated with a number of physiological processes including development, differentiation, neurodegenerative diseases, infection, and cancer (3). Autophagy marker Light Chain 3 (LC3) was originally identified as a subunit of microtubule-associated proteins 1A and 1B (termed MAP1LC3) (4) and subsequently found to contain similarity to the yeast protein Apg8/Aut7/Cvt5 critical for autophagy (5). Three human LC3 isoforms (LC3A, LC3B, and LC3C) undergo post-translational modifications during autophagy (6-9). Cleavage of LC3 at the carboxy terminus immediately following synthesis yields the cytosolic LC3-I form. During autophagy, LC3-I is converted to LC3-II through lipidation by a ubiquitin-like system involving Atg7 and Atg3 that allows for LC3 to become associated with autophagic vesicles (6-10). The presence of LC3 in autophagosomes and the conversion of LC3 to the lower migrating form, LC3-II, have been used as indicators of autophagy (11).

$262
3 nmol
300 µl
SignalSilence® ERCC1 siRNA I from Cell Signaling Technology (CST) allows the researcher to specifically inhibit ERCC1 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 protein expression by western analysis.
REACTIVITY
Human

Background: DNA repair systems operate in all living cells to manage a variety of DNA lesions. Nucleotide excision repair (NER) is implemented in cases where bulky helix-distorting lesions occur, such as those brought about by UV and certain chemicals (1). Excision Repair Cross Complementing 1 (ERCC1) forms a complex with ERCC4/XPF, which acts as the 5’ endonuclease required to excise the lesion (2). ERCC1-XPF is also required for repair of DNA interstrand crosslinks (ICLs) (3) and involved in repair of double strand breaks (4). Research studies have shown that expression of ERCC1 is related to survival rate and response to chemotherapeutic drugs in several human cancers including non-small cell lung cancer (NSCLC) (5,6).

$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 ALK (C26G7) Rabbit mAb #3333.
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Anaplastic lymphoma kinase (ALK) is a tyrosine kinase receptor for pleiotrophin (PTN), a growth factor involved in embryonic brain development (1-3). In ALK-expressing cells, PTN induces phosphorylation of both ALK and the downstream effectors IRS-1, Shc, PLCγ, and PI3 kinase (1). ALK was originally discovered as a nucleophosmin (NPM)-ALK fusion protein produced by a translocation (4). Investigators have found that the NPM-ALK fusion protein is a constitutively active, oncogenic tyrosine kinase associated with anaplastic lymphoma (4). Research literature suggests that activation of PLCγ by NPM-ALK may be a crucial step for its mitogenic activity and involved in the pathogenesis of anaplastic lymphomas (5).A distinct ALK oncogenic fusion protein involving ALK and echinoderm microtubule-associated protein like 4 (EML4) has been described in the research literature from a non-small cell lung cancer (NSCLC) cell line, with corresponding fusion transcripts present in some cases of lung adenocarcinoma. The short, amino-terminal region of the microtubule-associated protein EML4 is fused to the kinase domain of ALK (6-8).

$348
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 555 fluorescent dye and tested in-house for direct flow cytometry and immunofluorescent analysis in human cells. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated PDGF Receptor α (D13C6) XP® Rabbit mAb #5241.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry, Immunofluorescence (Immunocytochemistry)

Background: Platelet derived growth factor (PDGF) family proteins exist as several disulphide-bonded, dimeric isoforms (PDGF AA, PDGF AB, PDGF BB, PDGF CC, and PDGF DD) that bind in a specific pattern to two closely related receptor tyrosine kinases, PDGF receptor α (PDGFRα) and PDGF receptor β (PDGFRβ). PDGFRα and PDGFRβ share 75% to 85% sequence homology between their two intracellular kinase domains, while the kinase insert and carboxy-terminal tail regions display a lower level (27% to 28%) of homology (1). PDGFRα homodimers bind all PDGF isoforms except those containing PDGF D. PDGFRβ homodimers bind PDGF BB and DD isoforms, as well as the PDGF AB heterodimer. The heteromeric PDGF receptor α/β binds PDGF B, C, and D homodimers, as well as the PDGF AB heterodimer (2). PDGFRα and PDGFRβ can each form heterodimers with EGFR, which is also activated by PDGF (3). Various cells differ in the total number of receptors present and in the receptor subunit composition, which may account for responsive differences among cell types to PDGF binding (4). Ligand binding induces receptor dimerization and autophosphorylation, followed by binding and activation of cytoplasmic SH2 domain-containing signal transduction molecules, such as GRB2, Src, GAP, PI3 kinase, PLCγ, and NCK. A number of different signaling pathways are initiated by activated PDGF receptors and lead to control of cell growth, actin reorganization, migration, and differentiation (5). Tyr751 in the kinase-insert region of PDGFRβ is the docking site for PI3 kinase (6). Phosphorylated pentapeptides derived from Tyr751 of PDGFRβ (pTyr751-Val-Pro-Met-Leu) inhibit the association of the carboxy-terminal SH2 domain of the p85 subunit of PI3 kinase with PDGFRβ (7). Tyr740 is also required for PDGFRβ-mediated PI3 kinase activation (8).

$142
250 µl
Anti-mouse IgG (H+L), F(ab')2 Fragment was conjugated to Alexa Fluor® 594 fluorescent dye under optimal conditions and formulated at 2 mg/ml. This F(ab')2 fragment product results in less non-specific binding, as it lacks the Fc domain that can bind to the cells with Fc receptors.
APPLICATIONS

Application Methods: Flow Cytometry, Immunofluorescence (Immunocytochemistry)

$142
250 µl
Anti-rabbit IgG (H+L), F(ab')2 Fragment was conjugated to Alexa Fluor® 594 fluorescent dye under optimal conditions and formulated at 2 mg/ml. This F(ab')2 fragment product results in less non-specific binding, as it lacks the Fc domain that can bind to the cells with Fc receptors.
APPLICATIONS

Application Methods: Flow Cytometry, Immunofluorescence (Immunocytochemistry)

$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: Survivin is a 16 kDa anti-apoptotic protein highly expressed during fetal development and cancer cell malignancy (1). Survivin binds and inhibits caspase-3, controlling the checkpoint in the G2/M-phase of the cell cycle by inhibiting apoptosis and promoting cell division (2,3). This regulatory process requires the phosphorylation of survivin at Thr34 by p34 cdc2 kinase (4). Gene targeting using a Thr34 phosphorylation-defective survivin mutant, as well as antisense survivin, have been shown to inhibit tumor growth (5,6).

$203
250 µl
Anti-mouse IgG (H+L), F(ab')2 Fragment was conjugated to phycoerythrin (PE) under optimal conditions and formulated at 1 mg/ml. This F(ab')2 fragment results in less non-specific binding to cells through Fc receptors.
APPLICATIONS

Application Methods: Flow Cytometry

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Western Blotting

Background: PICH is a helicase of the SNF2 family of ATPases and is essential for proper chromosome segregation during mitosis (1). While PICH was originally proposed to participate in spindle assembly checkpoint signaling (1), that function was subsequently called into question (2). When phosphorylated at Thr1063 by CDK1, PICH binds the polo-box domain of the mitotic kinase PLK1 (1) and targets it to chromosome arms (3), where it appears to facilitate proper chromosome arm cohesion (4). PICH is also a substrate of PLK1 (1). Localized to the cytoplasm during interphase, PICH begins to accumulate at centromeres and kinetochores in prometaphase (4). As chromosomes begin to separate at the onset of anaphase, PICH associates with ultrafine threads between sister centromeres thought to be composed of entangled DNA (5), a natural consequence of DNA replication. PICH is proposed to cooperate with BLM, a RecQ-like helicase implicated in the genetic disorder Bloom’s Syndrome, to displace centromeric histones along these threads, thus enabling them to span large distances without breaking (6). This provides a temporal window for topoisomerase IIα-mediated disentanglement (7). Defects in PICH or BLM disrupt proper chromatid segregation and result in the formation of micronuclei (6).

$203
250 µl
Anti-rabbit IgG (H+L), F(ab')2 Fragment was conjugated to phycoerythrin (PE) under optimal conditions and formulated at 1 mg/ml. This F(ab')2 fragment results in less non-specific binding to cells through Fc receptors.
APPLICATIONS

Application Methods: Flow Cytometry

$348
100 µl
This Cell Signaling Technology® antibody is conjugated to the carbohydrate groups of horseradish peroxidase (HRP) via its amine groups. The HRP conjugated antibody is expected to exhibit the same species cross-reactivity as the unconjugated GAPDH (D16H11) XP® Rabbit mAb #5174.
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Western Blotting

Background: Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) catalyzes the phosphorylation of glyceraldehyde-3-phosphate during glycolysis. Though differentially expressed from tissue to tissue (1), GAPDH is thought to be a constitutively expressed housekeeping protein. For this reason, GAPDH mRNA and protein levels are often measured as controls in experiments quantifying specific changes in expression of other targets. Recent work has elucidated roles for GAPDH in apoptosis (2), gene expression (3), and nuclear transport (4). GAPDH may also play a role in neurodegenerative pathologies such as Huntington and Alzheimer's diseases (4,5).

$262
3 nmol
300 µl
SignalSilence® Aurora A/AIK siRNA I from Cell Signaling Technology (CST) allows the researcher to specifically inhibit Aurora A/AIK 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: Aurora kinases belong to a highly conserved family of mitotic serine/threonine kinases with three members identified among mammals: Aurora A, B, and C (1,2). Studies on the temporal expression pattern and subcellular localization of Aurora kinases in mitotic cells suggest an association with mitotic structure. Aurora kinase functional influences span from G2 phase to cytokinesis and may be involved in key cell cycle events such as centrosome duplication, chromosome bi-orientation and segregation, cleavage furrow positioning, and ingression (3). Aurora A is detected at the centrosomes, along mitotic spindle microtubules, and in the cytoplasm of mitotically proliferating cells. Aurora A protein levels are low during G1 and S phases and peak during the G2/M phase of the cell cycle. Phosphorylation of Aurora A at Thr288 in its catalytic domain increases kinase activity. Aurora A is involved in centrosome separation, maturation, and spindle assembly and stability. Expression of Aurora B protein also peaks during the G2/M phase of the cell cycle; Aurora B kinase activity peaks at the transition from metaphase to the end of mitosis. Aurora B associates with chromosomes during prophase prior to relocalizing to the spindle at anaphase. Aurora B regulates chromosome segregation through the control of microtubule-kinetochore attachment and cytokinesis. Expression of both Aurora A and Aurora B during the G2/M phase transition is tightly coordinated with histone H3 phosphorylation (4,5); research investigators have observed overexpression of these kinases in a variety of human cancers (2,4). Aurora C localizes to the centrosome from anaphase to cytokinesis and both mRNA and protein levels peak during G2/M phase. Although typical Aurora C expression is limited to the testis, research studies report overexpression of Aurora C is detected in various cancer cell lines (6).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Western Blotting

Background: Insulin is a major hormone controlling critical energy functions, such as glucose and lipid metabolism. Insulin binds to and activates the insulin receptor (IR) tyrosine kinase, which phosphorylates and recruits adaptor proteins. The signaling pathway initiated by insulin and its receptor stimulates glucose uptake in muscle cells and adipocytes through translocation of the Glut4 glucose transporter from the cytoplasm to the plasma membrane (1). A 160 kDa substrate of the Akt Ser/Thr kinase (AS160, TBC1D4) is a Rab GTPase-activating protein that regulates insulin-stimulated Glut4 trafficking. AS160 is expressed in many tissues including brain, kidney, liver, and brown and white fat (2). Multiple Akt phosphorylation sites have been identified on AS160 in vivo, with five sites (Ser318, Ser570, Ser588, Thr642, and Thr751) showing increased phosphorylation following insulin treatment (2,3). Studies using recombinant AS160 demonstrate that insulin-stimulated phosphorylation of AS160 is a crucial step in Glut4 translocation (3) and is reduced in some patients with type 2 diabetes (4). The interaction of 14-3-3 regulatory proteins with AS160 phosphorylated at Thr642 is a necessary step for Glut4 translocation (5). Phosphorylation of AS160 by AMPK is involved in the regulation of contraction-stimulated Glut4 translocation (6).

$408
300 assays
Alexa Fluor® 488 Phalloidin allows researchers to fluorescently stain the cytoskeleton through the binding of phalloidin to F-actin. This product is intended for use on fixed and permeabilized samples due to the toxicity associated with phalloidin. After reconstitution the stock solution provides enough material to perform 300 assays based on a 1:20 dilution and a 100 μl assay volume.Alexa Fluor® 488 Fluorescent Properties: Excitation: 495, Emission: 518.
APPLICATIONS
REACTIVITY
All Species Expected

Application Methods: Immunofluorescence (Immunocytochemistry)

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

Application Methods: Immunoprecipitation, 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 sense and repair DSBs via two distinct but partly overlapping signaling pathways, nonhomologous end joining (NHEJ) and homologous recombination (HR). Research studies have shown that defects in both pathways are associated with human disease, including cancer (reviewed in 1).DSBs that arise during S or G2 phase are repaired via homologous recombination (HR), using the replicated sister chromatid as a repair template. Rad51 recombinase, a eukaryotic homologue of E. coli RecA, polymerizes and forms a filament along single-stranded DNA, mediating HR with the help of auxiliary proteins, including Rad54 and BRCA2 (reviewed in 2,3). BRCA2 binds Rad51 and targets it to single-stranded DNA, allowing it to displace replication protein A (RPA) (4). Five Rad51 paralogs exist in vertebrates (XRCC2, XRCC3, Rad51B, Rad51C, and Rad51D) and they all appear to be required for efficient HR (5).Researchers have found that mutations in the Rad51 gene may be related to breast cancer risk (6). Some studies have implicated Rad51 as a potential marker for pancreatic cancer (7).

$348
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 488 fluorescent dye and tested in-house for direct flow cytometry and immunofluorescent analysis in human cells. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated PDGF Receptor α (D13C6) XP® Rabbit mAb #5241.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry, Immunofluorescence (Immunocytochemistry)

Background: Platelet derived growth factor (PDGF) family proteins exist as several disulphide-bonded, dimeric isoforms (PDGF AA, PDGF AB, PDGF BB, PDGF CC, and PDGF DD) that bind in a specific pattern to two closely related receptor tyrosine kinases, PDGF receptor α (PDGFRα) and PDGF receptor β (PDGFRβ). PDGFRα and PDGFRβ share 75% to 85% sequence homology between their two intracellular kinase domains, while the kinase insert and carboxy-terminal tail regions display a lower level (27% to 28%) of homology (1). PDGFRα homodimers bind all PDGF isoforms except those containing PDGF D. PDGFRβ homodimers bind PDGF BB and DD isoforms, as well as the PDGF AB heterodimer. The heteromeric PDGF receptor α/β binds PDGF B, C, and D homodimers, as well as the PDGF AB heterodimer (2). PDGFRα and PDGFRβ can each form heterodimers with EGFR, which is also activated by PDGF (3). Various cells differ in the total number of receptors present and in the receptor subunit composition, which may account for responsive differences among cell types to PDGF binding (4). Ligand binding induces receptor dimerization and autophosphorylation, followed by binding and activation of cytoplasmic SH2 domain-containing signal transduction molecules, such as GRB2, Src, GAP, PI3 kinase, PLCγ, and NCK. A number of different signaling pathways are initiated by activated PDGF receptors and lead to control of cell growth, actin reorganization, migration, and differentiation (5). Tyr751 in the kinase-insert region of PDGFRβ is the docking site for PI3 kinase (6). Phosphorylated pentapeptides derived from Tyr751 of PDGFRβ (pTyr751-Val-Pro-Met-Leu) inhibit the association of the carboxy-terminal SH2 domain of the p85 subunit of PI3 kinase with PDGFRβ (7). Tyr740 is also required for PDGFRβ-mediated PI3 kinase activation (8).

$122
20 µl
$303
100 µl
APPLICATIONS
REACTIVITY
Human

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).

$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 ALK (D5F3®) XP® Rabbit mAb #3633.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry

Background: Anaplastic lymphoma kinase (ALK) is a tyrosine kinase receptor for pleiotrophin (PTN), a growth factor involved in embryonic brain development (1-3). In ALK-expressing cells, PTN induces phosphorylation of both ALK and the downstream effectors IRS-1, Shc, PLCγ, and PI3 kinase (1). ALK was originally discovered as a nucleophosmin (NPM)-ALK fusion protein produced by a translocation (4). Investigators have found that the NPM-ALK fusion protein is a constitutively active, oncogenic tyrosine kinase associated with anaplastic lymphoma (4). Research literature suggests that activation of PLCγ by NPM-ALK may be a crucial step for its mitogenic activity and involved in the pathogenesis of anaplastic lymphomas (5).A distinct ALK oncogenic fusion protein involving ALK and echinoderm microtubule-associated protein like 4 (EML4) has been described in the research literature from a non-small cell lung cancer (NSCLC) cell line, with corresponding fusion transcripts present in some cases of lung adenocarcinoma. The short, amino-terminal region of the microtubule-associated protein EML4 is fused to the kinase domain of ALK (6-8).

$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 p44/42 MAPK (Erk1/2) (137F5) Rabbit mAb #4695.
APPLICATIONS
REACTIVITY
Bovine, C. elegans, D. melanogaster, Dog, Hamster, Human, Mink, Monkey, Mouse, Pig, Rat, Zebrafish

Application Methods: Flow Cytometry

Background: Mitogen-activated protein kinases (MAPKs) are a widely conserved family of serine/threonine protein kinases involved in many cellular programs, such as cell proliferation, differentiation, motility, and death. The p44/42 MAPK (Erk1/2) signaling pathway can be activated in response to a diverse range of extracellular stimuli including mitogens, growth factors, and cytokines (1-3), and research investigators consider it an important target in the diagnosis and treatment of cancer (4). Upon stimulation, a sequential three-part protein kinase cascade is initiated, consisting of a MAP kinase kinase kinase (MAPKKK or MAP3K), a MAP kinase kinase (MAPKK or MAP2K), and a MAP kinase (MAPK). Multiple p44/42 MAP3Ks have been identified, including members of the Raf family, as well as Mos and Tpl2/COT. MEK1 and MEK2 are the primary MAPKKs in this pathway (5,6). MEK1 and MEK2 activate p44 and p42 through phosphorylation of activation loop residues Thr202/Tyr204 and Thr185/Tyr187, respectively. Several downstream targets of p44/42 have been identified, including p90RSK (7) and the transcription factor Elk-1 (8,9). p44/42 are negatively regulated by a family of dual-specificity (Thr/Tyr) MAPK phosphatases, known as DUSPs or MKPs (10), along with MEK inhibitors, such as U0126 and PD98059.

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

Application Methods: Western Blotting

Background: Glucose-6-phosphate dehydrogenase (G6PD) catalyses the first, and rate-limiting, step of the pentose phosphate pathway (1). The NADPH generated from this reaction is essential to protect cells from oxidative stress (1). Research studies have shown that p53 interacts with G6PD and inhibits its activity, therefore suppressing glucose consumption through the pentose phosphate pathway (2). In cancer cells with p53 mutations, the increased glucose consumption is directed towards increased biosynthesis, which is critical for cancer cell proliferation (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 p21 Waf1/Cip1 (12D1) Rabbit mAb #2947.
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Flow Cytometry

Background: The tumor suppressor protein p21 Waf1/Cip1 acts as an inhibitor of cell cycle progression. It functions in stoichiometric relationships forming heterotrimeric complexes with cyclins and cyclin-dependent kinases. In association with CDK2 complexes, it serves to inhibit kinase activity and block progression through G1/S (1). However, p21 may also enhance assembly and activity in complexes of CDK4 or CDK6 and cyclin D (2). The carboxy-terminal region of p21 is sufficient to bind and inhibit PCNA, a subunit of DNA polymerase, and may coordinate DNA replication with cell cycle progression (3). Upon UV damage or during cell cycle stages when cdc2/cyclin B or CDK2/cyclin A are active, p53 is phosphorylated and upregulates p21 transcription via a p53-responsive element (4). Protein levels of p21 are downregulated through ubiquitination and proteasomal degradation (5).