Phospho-MDM4 (Ser367) Antibody
Product Specs
Target Background
- Considering the lack of association between MDM4 rs4245739 polymorphism and breast cancer, it appears that this polymorphism does not significantly contribute to the disease's pathophysiology. PMID: 28164646
- Our research indicates that Mdm4-S overexpression is a consequence of splicing defects in tumor cells rather than a primary driver of tumor development. PMID: 28460439
- These findings suggest that the rs4245739 polymorphism may contribute to a decreased cancer susceptibility, supporting the hypothesis that genetic variations within the MDM4 genes act as important modifiers of cancer risk. PMID: 27738340
- Our study is the first to identify miR-766 as a novel p53 activator that functions by targeting MDM4 and thereby enhancing the p53 signaling pathway. PMID: 28430625
- Elevated MDM4 expression levels are associated with lymph node metastasis in gastric adenocarcinoma and influence the prognosis of patients with this type of cancer. PMID: 27626496
- The MDM4 rs4245739 A > C polymorphism appears to be associated with a reduced risk of cancer. PMID: 27687591
- Analyses indicated that rs4245739 polymorphism in the MDM4 gene may play a significant role in the development of cancer. PMID: 27742919
- Results revealed an allosteric ligand-binding mechanism of the N-terminal domain of MdmX, where the ligand initially interacts with a compact core, followed by enhanced intermolecular interactions with intrinsic flexible regions. PMID: 29023092
- Complex alterations of HDM4 proteins, which are critical regulators of cell cycle progression, are frequent defects in AML and HG-MDS cases. The high detection rates of HDM4 expression in this study, 92% in AML and 52% in MDS, suggest that HDM4 is a potential therapeutic target for patients with these diseases. PMID: 27155969
- The MDM4 rs1380576 G variant is associated with gastric cancer. PMID: 28099948
- These results demonstrate that cisplatin-mediated p53(V172F) mutation regulates p53 stability at normothermic temperatures, but it is the increased recruitment of MDM4 by the homomeric or heteromeric mutant p53(V172F) complex that inhibits p53-dependent transactivation. This represents a novel cellular mechanism of p53 inhibition and, consequently, the induction of cisplatin resistance. PMID: 26876197
- MDM4 protein is frequently abundant in the context of mutant p53 in basal-like breast cancer (BC) samples. MDM4 plays a critical role in the proliferation of these BC cells. MDM4 is crucial for the establishment and progression of tumors. PMID: 28097652
- This study utilized polymer statistics to estimate a global KD value for p53 binding to MdmX in the presence of the flexible linker and the intramolecular binding motif by assuming the flexible linker behaves as a wormlike chain. Calculations and measurements revealed that the intramolecular binding motif reduces the apparent affinity of p53 for MdmX by a factor of 400. PMID: 28487147
- Data indicate that knockdown of otubain 1 protein (Otub1) reduced the levels of double minute 4 protein (MDMX). PMID: 28035068
- These data identify MDM4 as a nutrient-sensor capable of inhibiting mTORC1 and highlight its metabolism-related tumor-suppressing function. PMID: 28270148
- Data indicate that two single-nucleotide polymorphisms (SNPs) rs10900598 and rs4245739, located at the 3'-untranslated region (UTR) of double minute 4 protein (MDM4) gene, contribute to the clinical outcome of advanced non-small cell lung cancer (NSCLC) patients treated with platinum-based chemotherapy. PMID: 27462918
- Identified a novel Her4-induced posttranslational modification on MDMX. PMID: 27777309
- The MDM4 SNP34091 polymorphism may function as a protective factor against cancer risk. PMID: 27646776
- Individuals carrying the MDM4 SNP34091AC/CC genotypes had a significantly elevated risk for serous ovarian cancer, particularly high-grade serous ovarian cancer. No association between SNP34091 genotypes and endometrial cancer risk was observed. PMID: 26867771
- These results suggest that secondary intermolecular interaction is important in p53 regulation by MDMX, which may represent a common phenomenon in complexes containing multidomain proteins. PMID: 27114532
- Authors demonstrate that the EMT phenotype in multiple cellular models and in clinical prostate and breast cancer samples is associated with a decrease in MDM2 and an increase in MDMX expression. PMID: 26416355
- MDM4 SNP34091 status is associated with reduced risk of breast cancer, particularly in individuals carrying the MDM2 SNP309GG genotype, but not associated with lung, colon, or prostate cancer. PMID: 26471763
- The phosphate group of pTyr99 imposes extensive steric clashes with the C-terminus of p53 peptide and induces a significant lateral shift of the peptide ligand, decreasing the binding affinity of MDMX for p53. PMID: 26148237
- MDM4/HIPK2/p53 cytoplasmic assembly reveals coordinated repression of molecules with anti-apoptotic activity during the early DNA damage response. PMID: 25961923
- The MDM4 rs4245739 single nucleotide polymorphism contributes to small cell lung cancer risk and supports the notion that gene 3'-UTR genetic variants, impacting miRNA-binding, might modify small cell lung cancer susceptibility. PMID: 26274820
- These results identify Mdmx growth dependency in wt p53 expressing breast cancer across a range of subtypes. Based on these findings, we propose that Mdmx targeting is a promising strategy for treating breast cancer harboring wt p53. PMID: 26181202
- MDM4 overexpression is related to complex karyotype-acute myeloid leukemia with wild-type TP53 and might play a pathogenic role by inhibiting the p53-signal pathway. PMID: 25405759
- MDMX exerts oncogenic activity via suppression of RB. PMID: 25703327
- Using reporter gene assays and endogenous MDM4 expression analyses, we demonstrate that miR-191-5p and miR-887 have a specific affinity for the rs4245739 SNP C-allele in prostate cancer. PMID: 25670033
- An MDM4 mutation identified in a glioma patient was associated with loss of the putative MDM4 target site. Therefore, let-7 binding to MDM4 is implicated in the DNA damage response. PMID: 26028311
- A strong association between the expression of EEF1A2, phosphorylated AKT, and MDM4 was observed in human HCC samples. Strong activation of the EEF1A2/PI3K/AKT/mTOR/MDM4 signaling pathway was observed in HCC patients. PMID: 25394965
- Confirmation that the residue Tyr99 in MDMX can generate a steric clash with the inhibitors due to energy and structure. PMID: 22408446
- The HDMX polymorphism is unlikely to contribute to individual susceptibility to sarcoma. PMID: 24972690
- The results indicate a putative role for the MDM4 gene in predicting local recurrence of bladder cancer. PMID: 25026175
- Endogenously high levels of Mdm4 inhibit and sequester p53 in AML. High levels of Mdm4 do not block the function of Mdm2 inhibitors in AML. PMID: 24659749
- In the absence of p53 or in the presence of MdmX overexpression, FL118 promotes p53-independent apoptosis. PMID: 25512388
- Downregulation of Mdm4 by miR-661 augments p53 activity and inhibits cell cycle progression in p53-proficient cells. PMID: 24141721
- Loss of MDM4 expression is associated with glioblastoma. PMID: 24445145
- The novel variant MDM4-B may play a role in glioma tumorigenesis or cancer progression. PMID: 23994448
- The activation level of the EEF1A2/PI3K/AKT/mTOR/MDM4 axis significantly influences the survival probability of hepatocellular carcinoma patients. PMID: 24285179
- Functional MDM4 rs4245739 SNP, alone and in combination with the P53 Arg72Pro genetic variant, was associated with a significantly decreased risk of breast cancer in Chinese populations. PMID: 23793604
- MDMX contains a regulatory element (the "WWW element") that binds to its own N-terminal domain and prevents MDMX from binding to p53. PMID: 24127580
- The MDM4 rs4245739 (miR-191 target site) AC and CC genotypes were significantly associated with a decreased risk of esophageal squamous cell carcinoma. PMID: 23724042
- Mdm4 is upregulated in a substantial proportion of stage I-IV human melanomas. It promotes the survival of metastatic melanoma by antagonizing p53. In xenografts, inhibition of the MDM4-p53 interaction restored p53 function. PMID: 22820643
- The interaction of nutlin with MDMX is very short-lived compared with MDM2 and does not exhibit such direct initial interactions with the binding site. PMID: 23324352
- The rs1563828(C > T) polymorphism in the MDM4 gene may not confer risk to breast cancer, especially for early-onset breast cancer patients. Homozygous TT of rs1563828 is associated with a younger age of onset of breast cancer. PMID: 22490292
- FULL length-MDM4 and a splicing variant of MDM4 overexpression are indicators of p53 aberrations in chronic lymphocytic leukemia patients, suggesting that these patients have a poor prognosis. PMID: 22937789
- MicroRNA-34a modulates MDM4 expression via a target site in the open reading frame. PMID: 22870278
- The results of this study showed a strong association between MDM4 gene alternation and high-grade oligodendroglial tumors. PMID: 22825724
- DNA damage activates p53 in part by disrupting CK1a-MDMX interaction and reducing MDMX-p53 binding affinity. PMID: 23028042
Q&A
Advanced Research Questions
-
How is MDM4 Ser367 phosphorylation regulated in response to DNA damage?
DNA damage induces rapid phosphorylation of MDM4 at Ser367 through several mechanisms:
-
Ser367 is phosphorylated by Chk2 kinase downstream of ATM in response to DNA damage
-
Different DNA-damaging agents induce varying degrees of S367 phosphorylation:
Experimental approach for studying this pathway:
-
-
What is the relationship between MDM4 Ser367 phosphorylation, 14-3-3 binding, and MDM2-mediated degradation?
MDM4 phosphorylation at Ser367 initiates a regulatory cascade:
-
Phosphorylation at Ser367 creates a binding site for 14-3-3 proteins
-
14-3-3 binding promotes nuclear translocation of MDM4
-
In the nucleus, MDM4 becomes accessible to MDM2-mediated ubiquitination
-
Ubiquitinated MDM4 undergoes proteasomal degradation
-
Reduction in MDM4 levels relieves inhibition of p53, allowing p53 activation
This mechanism can be experimentally verified by:
-
-
How does the S367A mutation affect MDM4's function in experimental systems?
The S367A mutation provides a valuable tool for studying MDM4 regulation:
-
S367A abolishes binding of MDM4 to 14-3-3 proteins
-
The mutant is more resistant to MDM2-dependent ubiquitination and degradation
-
S367A enhances the ability of MDM4 to repress p53 transcriptional activity when co-expressed with MDM2
-
The mutation promotes growth of normal human fibroblasts after introduction of MDM4
Experimental data shows that while wild-type MDM4 levels decrease after MDM2 co-expression, the S367A mutant maintains stable expression levels, indicating resistance to MDM2-mediated degradation .
-
-
What methodological approaches can optimize detection of phosphorylated MDM4 in experimental models?
For optimal detection of phosphorylated MDM4:
-
Cell treatment considerations:
-
Use proteasome inhibitors (MG132) to prevent degradation of phosphorylated MDM4
-
Consider the time course of phosphorylation (rapid for gamma irradiation, slower for UV)
-
-
Western blot optimization:
-
Sample preparation: Use phosphatase inhibitors in lysis buffers
-
Loading controls: Compare with total MDM4 levels using non-phospho-specific antibodies
-
Blocking: 5% BSA in TBST often yields better results than milk for phospho-epitopes
-
-
Validation approaches:
-
-
How can Phospho-MDM4 (Ser367) Antibodies be used to study DNA damage response dynamics?
These antibodies enable detailed analysis of the temporal relationship between DNA damage, MDM4 phosphorylation, and p53 activation:
-
Time-course experiments reveal that phosphorylation occurs rapidly after damage (within 1-2 hours for gamma radiation)
-
Co-staining with gamma-H2AX (DNA damage marker) and phospho-MDM4 can reveal spatial relationships
-
Multi-parameter analysis comparing MDM4 phosphorylation, binding to 14-3-3, and subsequent degradation provides insights into the kinetics of the pathway
-
Different DNA damaging agents can be compared for their efficiency in inducing MDM4 phosphorylation
Importantly, research shows that induction of S367 phosphorylation after DNA damage is associated with increased binding of MDM4 to 14-3-3 and accelerated MDM4 degradation, providing a mechanism for p53 activation .
-
-
What is the relationship between MDM4 Ser367 phosphorylation and other post-translational modifications?
MDM4 undergoes multiple phosphorylation events that function in concert:
-
S367 phosphorylation is the most prominent modification site in metabolic labeling experiments
-
S367A substitution significantly reduces ubiquitination by MDM2, whereas S342A and S403A substitutions have negligible effects
-
In addition to C-terminal phosphorylation sites, the p53-binding domain of MDM4 can be phosphorylated by c-Abl on Tyr-99 and Tyr-55
-
Phosphorylation of Tyr-99 interferes with p53 binding, potentially facilitating p53 activation
This complex pattern of modifications allows for nuanced regulation of MDM4 function in response to various cellular stresses. Experimentally, this can be studied using multiple phospho-specific antibodies and site-directed mutagenesis approaches .
-
-
How do different Phospho-MDM4 (Ser367) Antibody clones compare in research applications?
Available antibodies vary in their properties:
Antibody Type Host Clone Applications Special Features Polyclonal Rabbit N/A WB, IHC Broad epitope recognition Monoclonal Mouse #15 WB, ELISA, IHC, IP Higher specificity, consistent lot-to-lot Considerations for selection:
-
Polyclonal antibodies may offer higher sensitivity but potentially more background
-
Monoclonal antibodies provide consistent results between experiments
-
Some clones may perform better in specific applications (e.g., IHC versus WB)
-
Validation data from manufacturers should be consulted for specific research needs
-
-
How can Phospho-MDM4 (Ser367) Antibodies contribute to cancer research?
These antibodies provide valuable tools for cancer research:
-
MDM4 is overexpressed in various cancers including lung cancer, breast cancer, retinoblastoma, and leukemia
-
Phosphorylation status of MDM4 at Ser367 may reflect the functional state of the DNA damage response pathway in tumor cells
-
Altered phosphorylation patterns could indicate defects in ATM/Chk2 signaling
-
Therapeutic strategies targeting MDM4 could be monitored using phospho-specific antibodies
Research applications include:
-
Research Troubleshooting
-
What are common technical challenges when working with Phospho-MDM4 (Ser367) Antibodies?
Common issues and solutions include:
For troubleshooting specificity issues, comparing wild-type samples with the S367A mutant can provide definitive verification of antibody specificity .
-
How should researchers design experiments to study dynamic MDM4 phosphorylation?
Effective experimental design should include:
-
Treatment conditions:
-
Standardize DNA damage doses (e.g., 10 Gy gamma irradiation, 10 μM etoposide)
-
Include multiple time points (15min, 30min, 1h, 2h, 4h, 8h)
-
Use MG132 in parallel samples to capture total phosphorylation events
-
-
Controls:
-
Phosphatase treatment of samples as negative control
-
S367A mutant expression as specificity control
-
Total MDM4 antibody to normalize phospho-signal
-
-
Readouts:
-
Western blot for bulk analysis
-
Immunofluorescence for subcellular localization
-
Co-immunoprecipitation for 14-3-3 binding
-
p53 target gene expression as functional outcome
-
This comprehensive approach enables tracking of the complete regulatory pathway from MDM4 phosphorylation to p53 activation .
-
