REGgamma (also called PA28gamma or PSME3) is a proteasome activator involved in the degradation of several proteins that regulate cell cycle and transcription. Recently, we demonstrated that this protein has a role also in the maintenance of chromosomal stability and in the response to spindle damaging agents. Here we report for the first time that REGgamma interacts with the promyelocytic leukemia protein (PML), accumulates in PML nuclear bodies (PML-NBs), but it does not play any role in normal or arsenic-induced PML degradation. However, REGgamma seems to regulate PML-NBs number, since its deficiency causes an increase in PML-NBs, which can be overcome by increased levels of SUMO1, and its overexpression has the opposite effect. We additionally found that REGgamma interacts with the DNA damage checkpoint kinase Chk2, whose presence is necessary for the increase of PML-NBs induced by REGgamma deficiency, and that REGgamma depletion resulted in a partial restoration of PML-NBs in APL derived cells. Altogether, these results underline a new role for REGgamma in the control and regulation of PML subnuclear structures.
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http://dx.doi.org/10.4161/cc.8.15.9084 | DOI Listing |
Sci Adv
January 2025
Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei, China.
The proteasome degrades most superfluous and damaged proteins, and its decline is associated with many diseases. As the proteolytic unit, the 20 proteasome is assembled from 28 subunits assisted by chaperones PAC1/2/3/4 and POMP; then, it undergoes the maturation process, in which the proteolytic sites are activated and the assembly chaperones are cleared. However, mechanisms governing the maturation remain elusive.
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January 2025
Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA; Graduate Program in Cell and Molecular Biology, University of Michigan, Ann Arbor, MI, USA; Medical Scientist Training Program, University of Michigan, Ann Arbor, MI, USA; Department of Neurology, University of Michigan, Ann Arbor, MI, USA. Electronic address:
The nuclear RNA-binding protein TDP43 is integrally involved in the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Previous studies uncovered N-terminal TDP43 isoforms that are predominantly cytosolic in localization, prone to aggregation, and enriched in susceptible spinal motor neurons. In healthy cells, however, these shortened (s)TDP43 isoforms are difficult to detect in comparison to full-length (fl)TDP43, raising questions regarding their origin and selective regulation.
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December 2024
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, School of Marine Sciences, Ningbo University, Ningbo 315211, China.
Ubiquitin-conjugating enzyme E2 T (UBE2T) is a crucial E2 enzyme in the ubiquitin-proteasome system (UPS), playing a significant role in the ubiquitination of proteins and influencing a wide range of cellular processes, including proliferation, differentiation, apoptosis, invasion, and metabolism. Its overexpression has been implicated in various malignancies, such as lung adenocarcinoma, gastric cancer, pancreatic cancer, liver cancer, and ovarian cancer, where it correlates strongly with disease progression. UBE2T facilitates tumorigenesis and malignant behaviors by mediating essential functions such as DNA repair, apoptosis, cell cycle regulation, and the activation of oncogenic signaling pathways.
View Article and Find Full Text PDFElife
January 2025
Cell Biology, Hospital for Sick Children, Toronto, Canada.
Proliferating animal cells maintain a stable size distribution over generations despite fluctuations in cell growth and division size. Previously, we showed that cell size control involves both cell size checkpoints, which delay cell cycle progression in small cells, and size-dependent regulation of mass accumulation rates (Ginzberg et al., 2018).
View Article and Find Full Text PDFAnticancer Agents Med Chem
January 2025
Department of Chemistry, Illinois State University, Normal, Il, USA.
Many oncoproteins are important therapeutic targets because of their critical role in inducing rapid cell proliferation, which represents one of the salient hallmarks of cancer. Chronic Myeloid Leukemia (CML) is a cancer of hematopoietic stem cells that is caused by the oncogene BCR-ABL1. BCR-ABL1 encodes a constitutively active tyrosine kinase protein that leads to the uncontrolled proliferation of myeloid cells, which is a hallmark of CML.
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