MAPK11 Antibody
Description
Definition and Background
MAPK11 antibodies target the human MAPK11 protein (UniProt ID: Q15759), encoded by the MAPK11 gene on chromosome 22. This kinase, also termed p38β, belongs to the p38 MAPK family and regulates cellular responses to stressors like cytokines and oxidative damage . Antibodies against MAPK11 are critical for identifying its activation state (e.g., phosphorylated forms) and interactions in signaling pathways .
Antibody Structure and Development
Most MAPK11 antibodies are rabbit-derived polyclonal or monoclonal IgG antibodies. Key features include:
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Immunogen: Fusion proteins or synthetic peptides corresponding to MAPK11’s conserved regions .
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Specificity: Cross-reactivity with human, mouse, and rat isoforms due to high sequence homology .
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Detection Methods: Conjugated secondary antibodies (e.g., biotin, DyLight®488) or direct labeling for techniques like Western blot (WB) and immunofluorescence (IF) .
3.1. Mechanistic Studies
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Kinase Activation: Antibodies detect phosphorylated MAPK11 (p-MAPK11) at Thr180/Tyr182, critical for its enzymatic activity .
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Protein Interactions: Co-immunoprecipitation (Co-IP) studies reveal interactions with substrates like ATF2 and RUNX2 .
3.2. Disease Research
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Cancer: Overexpression of MAPK11 and p-MAPK11 correlates with poor prognosis in clear cell renal cell carcinoma (ccRCC). Knockdown studies using antibodies show reduced proliferation and migration in ccRCC cell lines .
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Neurodegeneration: MAPK11 antibodies identify elevated kinase activity in Huntington’s disease models, linking p-MAPK11 to mutant Huntingtin (mHTT) accumulation .
Table 2: Key Findings from MAPK11 Antibody-Based Studies
Therapeutic Target Validation
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Inhibitor Screening: MAPK11 antibodies validate compound efficacy in high-throughput screens. For example, Skepinone-L (IC<sub>50</sub>: 19.2 nM) and derivatives show promise in reducing MAPK11 activity .
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Biomarker Potential: p-MAPK11 levels in cancer tissues, identified via IHC, correlate with tumor grade and survival rates .
Product Specs
Target Background
- The two kinases HIPK3 and MAPK11 have a mutant HTT protein (mHTT)-dependent effect on Huntingtin (HTT) levels, providing a feedback mechanism where mHTT enhances its own level, contributing to mHTT accumulation and disease progression. PMID: 29151587
- Research indicates that p38beta is an unusual enzyme that autoregulates its basal, MAPKK-independent activity through multiple autophosphorylation events, which both enhance and suppress its catalytic activity. PMID: 26976637
- p38beta levels were significantly higher in esophageal squamous cell carcinoma tissues compared to paired normal controls. p38beta expression was found to be significantly associated with overall prognosis. PMID: 26666822
- Findings suggest that R-Ras regulates angiogenic activities of endothelial cells, in part, by inhibiting the p38MAPK-HSP27 axis of VEGF signaling. PMID: 27029009
- These findings indicate that coronin 1A modulates endothelial cell apoptosis by regulating p38beta expression and activation. PMID: 25936522
- The MAPK11 gene exhibited variable methylation in monozygotic twins discordant for depressive disorder. PMID: 25918994
- p38beta is a novel regulatory target of the transcription factor Pokemon and is positively regulated by Pokemon in hepatic cells. PMID: 23807508
- Data demonstrate that the p38 MAPK (p38) isoform (p38beta) mitogen-activated protein kinase 11 (MAPK11) is expressed in breast cancer cells. PMID: 25066918
- Differential roles for p38alpha and p38beta in the HGF-induced expression of key osteogenic markers were identified. PMID: 24673557
- A study identified the structural motif responsible for the unique autophosphorylation capability of p38beta and the motif inhibiting this activity in living cells. PMID: 25006254
- The study identifies Hsp27 as a novel target of ILK-p38beta signaling complexes, playing a crucial role in bladder cancer cell migration. PMID: 23435415
- In endothelial cells, p38alpha mediates apoptotic signaling, while p38beta and p38gamma transduce survival signaling. PMID: 22522454
- Overexpression of p38beta or Rac1 significantly enhanced (1.9- and 3.9-fold, respectively) tRA-stimulated NIS expression in MCF-7 cells. PMID: 22157753
- Results demonstrate that IFN-alpha can regulate growth inhibition of Jurkat cells through p38alpha and p38beta. PMID: 20053787
- p38alpha/p38beta and phosphoinositide 3-kinase are critical for Tat-induced IL-10 production. PMID: 20378550
- These results demonstrate that activin A induces erythroid differentiation of K562 cells through activation of the MKK6-p38alpha/p38beta pathway, and follistatin inhibits these effects. PMID: 20162623
- Findings show that p38 MAP kinase directly activates TACE and influences shedding in response to growth factors and Erk MAP kinase activation. PMID: 20188673
- p38 MAP Kinase suppresses the function of Mirk as a transcriptional activator only when cells are proliferating. PMID: 12384504
- The p38MAPK activation-Bax expression pathway might be involved in apoptosis induced by oxidative stress. PMID: 12510156
- Neurotoxicity of pneumolysin depends on activation of p38 mitogen-activated protein kinase. PMID: 12586546
- Activation of p38 MAPK is involved in the mitochondrial activation-mediated cell death pathway. PMID: 14522966
- SAPK2/p38 intervenes in the control of MonoMac6 cell migration induced by monocyte chemoattractant protein-1. PMID: 14688370
- Phosphorylation of Y1214 on VEGFR2 is required to trigger the sequential activation of Cdc42 and SAPK2/p38, and to drive the SAPK2/p38-mediated actin remodeling in stress fibers in endothelial cells exposed to VEGF. PMID: 14724572
- SAPK2/p38 mitogen-activated protein kinase is inhibited by PML in tumor cells. PMID: 15273249
- Cholesterol depletion alters involucrin gene expression through activation of p38alpha/beta. PMID: 15304097
- p38SAPK might be involved in the regulation of cyclin D3 levels, suggesting that this mechanism participates in the maturation of precursor T-cells. PMID: 15326477
- p38alpha and -beta mediate UV-induced, AP-1-mediated, c-Fos phosphorylation. PMID: 15708845
- p38 phosphorylation occurred in response to attack by Staphylococcus aureus alpha-toxin and streptolysin O, starting within minutes after toxin treatment and declining after several hours. PMID: 16643845
- The authors characterized the multisite phosphorylation of the ATF7 activation domain and identified one of the involved kinases, p38beta2 mitogen-activated protein kinase. PMID: 18950637
- Genistein protects human vascular endothelial cells against tumor necrosis factor-alpha-induced apoptosis through the p38beta mitogen-activated protein kinase. PMID: 19082897
- Specific isoforms of p38 and their sub-cellular localization may play distinct roles in modulating ischemic injury. PMID: 19706373
Q&A
How do researchers validate MAPK11 antibody specificity in Western blotting?
Validation requires a triad approach:
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Knockout/Knockdown Controls: Use siRNA or CRISPR-modified cell lines (e.g., HEK-293 or iPSC-derived cardiomyocytes) to confirm absence of the 42 kDa band .
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Multi-Tissue Cross-Verification: Compare reactivity in Jurkat cells (positive control) with tissues lacking MAPK11 expression .
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Epitope Comparison: Contrast antibodies targeting distinct regions (e.g., AA 133-161 vs. AA 251-363) to identify nonspecific bands .
Table 1: Validation Data from Commercial Antibodies
What protocols optimize MAPK11 detection in immunohistochemistry (IHC)?
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Antigen Retrieval: Use TE buffer (pH 9.0) for formalin-fixed paraffin-embedded (FFPE) human brain sections; citrate buffer (pH 6.0) for mouse skeletal muscle .
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Titration Range: Start at 1:20 dilution for high-abundance targets (e.g., ccRCC tissues), increasing to 1:200 for normal kidney .
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Signal Amplification: Combine with tyramide-based systems when using polyclonal antibodies to enhance low-expressing targets .
How should epitope location influence antibody selection?
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N-Terminal (AA 1-30): Suitable for detecting full-length MAPK11 in WB but prone to cross-reactivity with MAPK14 .
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Central Domain (AA 133-161): Ideal for IP/IF applications due to exposed loops in native conformation .
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C-Terminal (AA 334-359): Preferable for phosphorylation studies (e.g., Y182 detection) .
What mechanistic insights have phosphorylation-specific MAPK11 antibodies provided in cancer?
Phospho-MAPK11 (p-MAPK11) drives ccRCC progression by stabilizing RUNX2 via direct interaction:
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Co-Immunoprecipitation: Anti-p-MAPK11 antibodies confirmed physical binding to RUNX2 in 786-O cells (Figure 1G in ).
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Half-Life Assays: Cycloheximide chase experiments showed p-MAPK11 inhibition reduces RUNX2 stability by 60% (t½ from 8h to 3h) .
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Therapeutic Targeting: siRNA-mediated MAPK11 knockdown reduced ccRCC migration by 75% (Transwell assay) and proliferation by 40% (EdU assay) .
Table 2: Functional Impacts of MAPK11 Modulation in ccRCC
| Parameter | MAPK11 Knockdown (786-O Cells) | RUNX2 Overexpression |
|---|---|---|
| Migration (Cells/Field) | 85 ± 12 vs. 210 ± 18* | 290 ± 25 |
| EdU+ Cells (%) | 22% vs. 58%* | 72% |
| RUNX2 Protein Level | ↓60% | ↑300% |
| *Data from |
How can MAPK11 antibodies resolve conflicting data in TKI cardiotoxicity studies?
Contradictory reports on MAPK11’s cardioprotective vs. tumor-promoting roles require:
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Cell-Type-Specific Analysis: Use iPSC-derived cardiomyocytes (hiPSC-CMs) for cardiac assays vs. KCL-22 CML cells for oncology .
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Dual-Activity Validation: Confirm functional outcomes with phospho-specific antibodies (e.g., improved contractility post-MAPK11 inhibition correlates with p-MAPK11 ↓50% ).
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Time-Resolved WB: Monitor MAPK11 activation at 0, 15, 30 min post-TKI treatment to capture transient signaling .
What methodologies quantify MAPK11-RUNX2 interactions in live cells?
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Proximity Ligation Assay (PLA): Combine anti-MAPK11 (AA 133-161) and anti-RUNX2 antibodies to visualize <200 nm interactions in ccRCC cells .
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FRET-Based Biosensors: Use C-terminally tagged MAPK11 (e.g., mCerulean3) with RUNX2-mVenus to measure real-time binding kinetics .
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Phos-Tag™ Gels: Resolve phosphorylated MAPK11-RUNX2 complexes using 50 μM Phos-Tag™ in SDS-PAGE .
How to troubleshoot nonspecific bands in MAPK11 Western blots?
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Preabsorption Control: Incubate antibody (1:500) with 10x molar excess of immunogen peptide (AA 133-161) for 1h; eliminates >90% of off-target bands .
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Cross-Species Validation: Test mouse-reactive clones (e.g., F-3) on rat myocardial infarction models to exclude interspecies cross-reactivity .
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Buffer Optimization: Add 0.1% SDS to lysis buffer to dissociate MAPK11 from p38α/β complexes .
What in vivo models validate MAPK11 antibody specificity?
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Xenograft Tumors: Inject MAPK11-knockdown 786-O cells into NSG mice; correlate IHC signal intensity (1:50 dilution) with tumor volume (R² >0.85 expected) .
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Cardiac Injury Models: Induce myocardial ischemia in MAPK11-/- mice; confirm antibody failure to detect MAPK11 in knockouts vs. 40% signal retention in WT .
