In order to activate gene expression, transcription factors such as c-Jun have to reside in the nucleus. The abundance of c-Jun in the nucleus correlates with the activity of its target genes. As a consequence of excessive c-Jun activation, cells undergo apoptosis or changes in differentiation whereas decreased c-Jun function can reduce proliferation. In the present study we addressed how nuclear accumulation of the transcription factor c-Jun is regulated. First, we analyzed which functions of c-Jun are required for efficient nuclear accumulation. Mutants of c-Jun deficient in dimerization or DNA-binding show no defect in nuclear transport. Furthermore, c-Jun import into the nucleus of living cells occurred when the c-Jun phosphorylation sites were mutated as well in cells that lack the major c-Jun kinase, JNK, suggesting that c-Jun transport into the nucleus does not require JNK signaling. Conversely, however, binding of c-Jun seemed to enhance nuclear accumulation of JNK. In order to identify proteins that might be relevant for the nuclear translocation of c-Jun we searched for novel binding partners by a proteomic approach. In addition to the heat shock protein HSP70 and the DNA damage repair factors Ku70 and 80, we isolated human importin 8 as a novel interactor of c-Jun. Interaction of Imp 8 with c-Jun in human cells was confirmed by co-immunoprecipitation experiments. Nuclear accumulation of c-Jun does not require its functions as a transcription factor or the interaction with its kinase JNK. Interestingly, nuclear accumulation of JNK is regulated by interaction with c-Jun. Unraveling the mechanisms of c-Jun and JNK transport to the nucleus and its regulation will improve our understanding of their role in biological and pathophysiological processes.
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http://dx.doi.org/10.1016/j.bbrc.2011.03.092 | DOI Listing |
Drug Des Devel Ther
January 2025
Department of Anesthesiology, The Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China.
Introduction: The mechanism of remimazolam, a benzodiazepine that activates γ-aminobutyric acid a (GABAa) receptors, in cerebral ischemia/reperfusion (I/R) injury is not well understood. Therefore, we explored whether remimazolam activates protein kinase B (AKT)/glycogen synthase kinase-3β (GSK-3β)/nuclear factor erythroid 2-related factor 2 (NRF2) to attenuate brain I/R injury in transcerebral I/R-injured rats and transoxygenic glucose deprivation/reperfusion (OGD/R)-injured SY5Y cells.
Material And Methods: Remimazolam was added at the beginning of cell and rat reperfusion, and the PI3K/AKT inhibitor LY294002 was added to inhibit the AKT/GSK-3β/NRF2 pathway 24 h before cellular OGD/R treatment and 30 min before rat brain I/R treatment.
Mol Neurodegener
January 2025
College of Life Sciences and Oceanography, Brain Disease and Big Data Research Institute, Shenzhen University, Shenzhen, 518060, Guangdong, China.
Background: Astrocytes, the most abundant glial cell type in the brain, will convert into the reactive state in response to proteotoxic stress such as tau accumulation, a characteristic feature of Alzheimer's disease (AD) and other tauopathies. The formation of reactive astrocytes is partially attributed to the disruption of autophagy lysosomal signaling, and inhibiting of some histone deacetylases (HDACs) has been demonstrated to reduce the molecular and functional characteristics of reactive astrocytes. However, the precise role of autophagy lysosomal signaling in astrocytes that regulates tau pathology remains unclear.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Diagnostic Radiology, Yong Loo Lin School of Medicine, National University of Singapore, 119074, Singapore.
The emerging combination of chemotherapy and radionuclide therapy has been actively investigated to overcome the limitations of monotherapy and augment therapeutic efficacy. However, it remains a challenge to design a single delivery vehicle that can incorporate chemotherapeutics and radionuclides into a compact structure. Here, a chelator DOTA- or NOTA-modified Evans blue conjugated camptothecin molecule (EB-CPT) nanoprodrug was synthesized, which could self-assemble into nanoparticles due to its inherent amphiphilicity.
View Article and Find Full Text PDFNPJ Syst Biol Appl
January 2025
BIH Center for Regenerative Therapies (BCRT), Julius Wolff Institute (JWI), and Berlin Institute of Health (BIH); all Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), 10117, Berlin, Germany.
Coronavirus disease 2019 (COVID-19) presents a wide spectrum of symptoms, the causes of which remain poorly understood. This study explored the associations between autoantibodies (AABs), particularly those targeting G protein-coupled receptors (GPCRs) and renin‒angiotensin system (RAS) molecules, and the clinical manifestations of COVID-19. Using a cross-sectional analysis of 244 individuals, we applied multivariate analysis of variance, principal component analysis, and multinomial regression to examine the relationships between AAB levels and key symptoms.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
December 2024
School of Basic Medical Sciences, Guangzhou University of Chinese Medicine Guangzhou 511400, China.
The aim of this study was to investigate the underlying mechanism of chrysophanol(Chr) in reducing inflammation and foam cell formation induced by oxidized low-density lipoprotein(ox-LDL) and to investigate the targets and pathways related to effects of Chr on coronary atherosclerosis, providing a theoretical basis for the development of new clinical drugs. RAW264.7 macrophages were cultured in vitro, and after determining the appropriate concentrations of Chr and ox-LDL for treating RAW264.
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