The conserved protein kinase Rio1 localizes to the cytoplasm and nucleus of eukaryotic cells. While the roles of Rio1 in the cytoplasm are well characterized, its nuclear function remains unknown. Here we show that nuclear Rio1 promotes rDNA array stability and segregation in Saccharomyces cerevisiae. During rDNA replication in S phase, Rio1 downregulates RNA polymerase I (PolI) and recruits the histone deacetylase Sir2. Both interventions ensure rDNA copy-number homeostasis and prevent the formation of extrachromosomal rDNA circles, which are linked to accelerated ageing in yeast. During anaphase, Rio1 downregulates PolI by targeting its subunit Rpa43, causing PolI to dissociate from the rDNA. By stimulating the processing of PolI-generated transcripts at the rDNA, Rio1 allows for rDNA condensation and segregation in late anaphase. These events finalize the genome transmission process. We identify Rio1 as an essential nucleolar housekeeper that integrates rDNA replication and segregation with ribosome biogenesis.
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http://dx.doi.org/10.1038/ncomms7643 | DOI Listing |
BMC Microbiol
January 2025
The Marine Science Institute, College of Science, University of the Philippines Diliman, Quezon City, Philippines.
Background: The observed growth variability of different aquaculture species in captivity hinders its large-scale production. For the sandfish Holothuria scabra, a tropical sea cucumber species, there is a scarcity of information on its intestinal microbiota in relation to host growth, which could provide insights into the processes that affect growth and identify microorganisms with probiotic or biochemical potential that could improve current production strategies. To address this gap, this study used 16 S rRNA amplicon sequencing to characterize differences in gut and fecal microbiota among large and small juveniles reared in floating ocean nurseries.
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January 2025
National Key Laboratory of Lead Druggability Research, Shanghai Institute of Pharmaceutical Industry, State Institute of Pharmaceutical Industry, 201203, Shanghai, People's Republic of China.
In Traditional Chinese Medicine (TCM), the medicinal leech is vital for treatments to promote blood circulation and eliminate blood stasis. However, the prevalence of counterfeit leech products in the market undermines the quality and efficacy of these remedies. Traditional DNA barcoding techniques, such as the COI barcode, have been limited in their application due to amplification challenges.
View Article and Find Full Text PDFTransl Psychiatry
January 2025
Laboratory of Exercise and Neurobiology, School of Physical Education and Sports Science, South China Normal University, Guangzhou, 510006, Guangdong, China.
Repeated closed-head injuries (rCHI) from activities like contact sports, falls, military combat, and traffic accidents pose a serious risk due to their cumulative impact on the brain. Often, rCHI is not diagnosed until symptoms of irreversible brain damage appear, highlighting the need for preventive measures. This study assessed the prophylactic efficacy of remote photobiomodulation (PBM) targeted at the lungs against rCHI-induced brain injury and associated behavioral deficits.
View Article and Find Full Text PDFGenes Dev
December 2024
Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5T 3H7, Canada;
The nucleolus is a major subnuclear compartment where ribosomal DNA (rDNA) is transcribed and ribosomes are assembled. In addition, recent studies have shown that the nucleolus is a dynamic organizer of chromatin architecture that modulates developmental gene expression. rDNA gene units are assembled into arrays located in the p-arms of five human acrocentric chromosomes.
View Article and Find Full Text PDFCancers (Basel)
December 2024
Wolfson Institute of Population Health, Faculty of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK.
Background/objectives: Several independent studies have associated prostate cancer (PCa) with specific groups of bacteria, most of them reporting the presence of anaerobic or microaerophilic species such as (). Such findings suggest a prostate cancer-related bacterial dysbiosis, in a manner similar to the association between infection and gastric cancer. In an earlier exploratory study looking for such dysbiosis events, using a culturomics approach, we discovered that the presence of obligate anaerobes (OAs) along with was associated with increased prostate-specific antigen (PSA) levels in 39 participants.
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