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We here show a new relationship between the human p14ARF oncosuppressor and the MDM2 oncoprotein. MDM2 overexpression in various cancer cell lines causes p14ARF reduction inducing its degradation through the proteasome. The effect does not require the ubiquitin ligase activity of MDM2 and preferentially occurs in the cytoplasm. Interestingly, treatment with inhibitors of the PKC (Protein Kinase C) pathway and use of p14ARF phosphorylation mutants indicate that ARF phosphorylation could play a role in MDM2 mediated ARF degradation reinforcing our previous observations that ARF phosphorylation influences its stability and biological activity. Our study uncovers a new potentially important mechanism through which ARF and MDM2 can counterbalance each other during the tumorigenic process.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4344200 | PMC |
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0117252 | PLOS |
Int J Mol Sci
August 2025
Département de Médecine-Service de Cardiologie, Centre de Recherche du CHUS, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.
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View Article and Find Full Text PDFAdv Sci (Weinh)
September 2025
Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
Uncontrolled cell proliferation drives tumorigenesis and malignant progression, making cell cycle regulation a promising strategy for cancer therapy. Phosphorylation plays pivotal roles in cancer initiation and metastasis by regulating the cancer-related proteins. Identifying key phosphorylation sites is essential for inhibiting tumor cell proliferation and optimizing therapy strategy.
View Article and Find Full Text PDFPhytomedicine
August 2025
School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, China. Electronic address:
Background: Aging affects the function of multiple organs, including the spleen, which undergoes age-related structural changes and functional decline. Polygonatum sibiricum, a traditional anti-aging herbal medicine, contains saponins as its primary active components. However, the potential effects and underlying mechanisms of Polygonatum n-butanol extract (PNBE), which is rich in saponins, on splenic aging remain to be elucidated.
View Article and Find Full Text PDFMol Cell Biol
June 2025
Department of Medicine, Division of Molecular Oncology, Washington University School of Medicine, Saint Louis, Missouri, USA.
The tumor suppressors p53 and ARF collaborate to prevent unwarranted cell proliferation and as such are two of the most frequently mutated genes in human cancer. Concomitant loss of functional p53 and ARF leads to massive gains in cell proliferation and transformation and is often observed in some of the most aggressive human cancer subtypes. These phenotypic gains are preceded by increased type I interferon (IFN) signaling that involves canonical STAT1 activation and a subsequent IFN-stimulated gene (ISG) signature.
View Article and Find Full Text PDFJ Cell Sci
May 2025
Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan.
Activation of extracellular signal-regulated kinases 1 and 2 (Erk1/2; also known as MAPK3 and MAPK1, respectively) at the plasma membrane usually leads to their translocation to various intracellular sites, where scaffolding proteins mediate substrate targeting. However, in platelet-derived growth factor (PDGF)-induced signaling, Erk1/2 phosphorylate Pak1 to drive cell migration while remaining at the plasma membrane, raising the question of whether scaffolding proteins are required. Similarly, the small GTPase Arf-like protein 4D (Arl4D) promotes cell migration by recruiting Pak1 to the plasma membrane and facilitating its phosphorylation, although the mechanism linking recruitment to phosphorylation remains unclear.
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