Polycomb group (PcG) proteins control development and cell proliferation through chromatin-mediated transcriptional repression. We describe a transcription-independent function for PcG protein Posterior sex combs (PSC) in regulating the destruction of cyclin B (CYC-B). A substantial portion of PSC was found outside canonical PcG complexes, instead associated with CYC-B and the anaphase-promoting complex (APC). Cell-based experiments and reconstituted reactions established that PSC and Lemming (LMG, also called APC11) associate and ubiquitylate CYC-B cooperatively, marking it for proteosomal degradation. Thus, PSC appears to mediate both developmental gene silencing and posttranslational control of mitosis. Direct regulation of cell cycle progression might be a crucial part of the PcG system's function in development and cancer.
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http://dx.doi.org/10.1126/science.1215927 | DOI Listing |
Redox Biol
February 2025
Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, 7491, Trondheim, Norway; Department of Neurology and Clinical Neurophysiology, University Hospital of Trondheim, 7006, Trondheim, Norway. Electronic address:
8-oxo-7,8-dihydroguanine (OG) is one of the most abundant oxidative lesions in the genome and is associated with genome instability. Its mutagenic potential is counteracted by a concerted action of 8-oxoguanine DNA glycosylase (OGG1) and mutY homolog DNA glycosylase (MUTYH). It has been suggested that OG and its repair has epigenetic-like properties and mediates transcription, but genome-wide evidence of this interdependence is lacking.
View Article and Find Full Text PDFPlant Cell
October 2024
Plant Immunity Research Group, RIKEN Center for Sustainable Resource Science (CSRS), Yokohama, Kanagawa 230-0045, Japan.
Mol Biol Cell
November 2024
Department of Molecular Biology, Virtua Health College of Medicine and Life Sciences, Rowan University, Stratford, NJ 08084.
The Cdk8 kinase module (CKM), a conserved, detachable unit of the Mediator complex, plays a vital role in regulating transcription and communicating stress signals from the nucleus to other organelles. Here, we describe a new transcription-independent role for Med13, a CKM scaffold protein, following nitrogen starvation. In , nitrogen starvation triggers Med13 to translocate to the cytoplasm.
View Article and Find Full Text PDFNucleic Acids Res
October 2024
Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Microprocessor is an essential nuclear complex responsible for the initial RNase-mediated cleavage of primary miRNA, which is a tightly controlled maturation process that requires the proper assembly of Drosha and DGCR8. Unlike previously identified mechanisms directly targeting the enzymatic subunit Drosha, current knowledge about the biological ways of controlling miRNA nuclear maturation through DGCR8 is less addressed. In this study, we unveiled that the microprocessor assembly is governed by a master gene regulator HIF-1α irrespective of its canonical transcriptional activity.
View Article and Find Full Text PDFJ Transl Med
September 2024
Centre for Pharmacology and Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
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