Dysfunction of the tumor suppressor p53 occurs in most human cancers, Hdm2 and HdmX play critical roles in p53 inactivation and degradation. Under unstressed conditions, HdmX binds to p53 like Hdm2, but HdmX cannot directly induce p53 degradation. Moreover, HdmX has been reported to stimulate Hdm2-mediated ubiquitination and degradation of p53. Here we reported that HdmX promoted the nuclear export of p53 independent of Hdm2 in living cells using FRET technology. Whereas, Hdm2 impeded HdmX-mediated nuclear export of p53 by sequestering it in nucleus. Interestingly, the C-terminal RING domain mutant Hdm2 formed heterooligomers with p53 in nucleus, which was inhibited by HdmX. The heterooligomers were located near PML-NBs. This study indicate that the nuclear Hdm2-HdmX interaction aborts the HdmX-mediated nuclear export of p53.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.yexcr.2024.114185 | DOI Listing |
PLoS One
January 2025
Facultad de Biológicas, Instituto de Biotecnología y Biomedicina (BIOTECMED), Universitat de València, Burjassot, Spain.
The budding yeast Xrn1 protein shuttles between the nucleus, where it stimulates transcription, and the cytoplasm, where it executes the major cytoplasmic mRNA decay. In the cytoplasm, apart from catalyzing 5'→3' decay onto non translated mRNAs, Xrn1 can follow the last translating ribosome to degrade the decapped mRNA template, a process known as "cotranslational mRNA decay". We have previously observed that the import of Xrn1 to the nucleus is required for efficient cytoplasmic mRNA decay.
View Article and Find Full Text PDFCase Rep Genet
January 2025
Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California, 2825 50th Street, Davis, Sacramento 95817, California, USA.
Fragile X syndrome (FXS) presents with autism spectrum disorder (ASD), intellectual disability, developmental delay, seizures, hypotonia during infancy, joint laxity, behavioral issues, and characteristic facial features. The predominant mechanism is due to CGG trinucleotide repeat expansion of more than 200 repeats in the 5'UTR (untranslated region) of (Fragile X Messenger Ribonucleoprotein 1) causing promoter methylation and transcriptional silencing. However, not all patients presenting with the characteristic phenotype and point/frameshift mutations with deletions in have been described in the literature.
View Article and Find Full Text PDFCell Mol Life Sci
January 2025
Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, Unitat de Farmacologia, Universitat de Barcelona, Av. Joan XXIII 27-31, 08028, Barcelona, Spain.
Nuclear growth differentiation factor 15 (GDF15) reduces the binding of the mothers' against decapentaplegic homolog (SMAD) complex to its DNA-binding elements. However, the stimuli that control this process are unknown. Here, we examined whether saturated fatty acids (FA), particularly palmitate, regulate nuclear GDF15 levels and the activation of the SMAD3 pathway in human skeletal myotubes and mouse skeletal muscle, where most insulin-stimulated glucose use occurs in the whole organism.
View Article and Find Full Text PDFCell Rep
January 2025
Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA; Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA; Carle Illinois College of Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA. Electronic address:
The influenza A virus nuclear export protein (NEP) is a multifunctional protein that is essential for the viral life cycle and has very high sequence conservation. However, since the open reading frame of NEP largely overlaps with that of another influenza viral protein, non-structural protein 1, it is difficult to infer the functional constraints of NEP based on sequence conservation analysis. In addition, the N-terminal of NEP is structurally disordered, which further complicates the understanding of its function.
View Article and Find Full Text PDFJ Biol Chem
January 2025
Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205 USA. Electronic address:
Kinase translocation reporters (KTRs) are powerful tools for single-cell measurement of time-integrated kinase activity but suffer from restricted dynamic range and limited sensitivity, particularly in neurons. To address these limitations, we developed enhanced KTRs (eKTRs) for protein kinase A (PKA) and extracellular signal-regulated kinase (ERK) by (i) increasing KTR size, which reduces the confounding effect of KTR diffusion through the nuclear pore, and (ii) modulating the strength of the bipartite nuclear localization signal (bNLS) in their kinase sensor domains, to ensures that the relative distribution of the KTR between the nucleus and cytoplasmic is determined by active nuclear import, active nuclear export, and relative activity of their cognate kinase. The resultant sets of ePKA-KTRs and eERK-KTRs display high sensitivity, broad dynamic range, and cell type-specific tuning.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!