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Updated: Jun 26, 2026
Purification of Ubiquitinated p53 Proteins from Mammalian Cells
Published on: March 21, 2022
Isolation and characterization of DUSP11, a novel p53 target gene
Greta Caprara1, Raffaella Zamponi1,2, Marina Melixetian1
1Department of Experimental Oncology, European Institute of Oncology, Via Adamello, Milano, Italy.
Abstract:
p53 regulates the expression of genes involved in cell cycle control, apoptosis and DNA damage repair. Here we demonstrate that DUSP11 (dual specificity phosphatase 11), a member of the protein tyrosine phosphatase family that binds to RNA-RNP complexes and RNA splicing factors, is a p53 target gene. Consistent with this, the expression of DUSP11 is induced in a p53-dependent manner after treatment with DNA damaging agents. Chromatin immunoprecipitation analysis showed that p53 binds to 2 putative p53 DNA binding sites in the promoter region of DUSP11. Colony formation and proliferation assays demonstrated that the ectopic expression of wildtype, but not catalytical inactive, DUSP11 leads to growth arrest. Furthermore inhibition of DUSP11 expression by shRNA increases the proliferation of normal and DNA damaged cells in tissue culture. Finally we show that the splicing factor SAM68 (Src-associated protein in mitotic cells) binds to DUSP11 in vitro and in vivo. Taken together these results suggest that DUSP11 contributes to p53-dependent inhibition of cell proliferation and that it might be involved in regulating RNA splicing through SAM68.
Insights
The tumor suppressor p53 targets the dual specificity phosphatase 11 (DUSP11) gene, which inhibits cell proliferation. DUSP11 also interacts with the splicing factor SAM68, suggesting a role in RNA splicing regulation.
Area of Science:
- Molecular Biology
- Cell Biology
- Genetics
Background:
- The p53 protein is a critical regulator of cellular responses to DNA damage, controlling cell cycle arrest, apoptosis, and DNA repair.
- Dual specificity phosphatases (DUSPs) are a family of enzymes involved in regulating cellular signaling pathways.
- RNA-binding proteins and splicing factors play crucial roles in post-transcriptional gene regulation.
Purpose of the Study:
- To investigate whether DUSP11 is a target gene of p53.
- To elucidate the role of DUSP11 in cell proliferation and its connection to p53.
- To explore the potential involvement of DUSP11 in RNA splicing regulation.
Main Methods:
- Chromatin immunoprecipitation (ChIP) assays to identify p53 binding sites in the DUSP11 promoter.
- Ectopic expression and shRNA-mediated knockdown of DUSP11 to assess its effect on cell proliferation.
- In vitro and in vivo binding assays to study the interaction between DUSP11 and SAM68.
Main Results:
- DUSP11 expression is induced in a p53-dependent manner following DNA damage.
- p53 directly binds to two putative binding sites in the DUSP11 promoter region.
- Ectopic expression of DUSP11 causes growth arrest, while its inhibition increases cell proliferation.
- DUSP11 interacts with the splicing factor SAM68.
Conclusions:
- DUSP11 is a novel p53 target gene that contributes to p53-mediated cell proliferation inhibition.
- DUSP11 may be involved in regulating RNA splicing, potentially through its interaction with SAM68.
- These findings reveal a new mechanism by which p53 controls cell growth and suggest a role for DUSP11 in RNA processing.
