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RECQ5 is a member of the RECQ helicase family that maintains genomic stability. However, the molecular mechanism of RECQ5 in this biological process remains elusive. Here, we show that RECQ5 localizes in the dense fibrillar component of nucleolus and associates with several pre-rRNA processing factors. It recognizes pre-rRNA and is able to unwind double-stranded RNA in vitro. Loss of RECQ5 induces the accumulation of 47S, 30SL5', and 30S pre-rRNA, and the reduction of 21S pre-rRNA, suggesting that it regulates the processing of pre-rRNA. Cancer-associated mutations of RECQ5 abolish its nucleolar localization as well as its helicase activities. Moreover, lacking RECQ5 leads to the unprocessed pre-rRNA hybridizing with rDNA, triggering the R-loop formation and ATR activation. Since both RECQ5 and ATR protect genomic stability in nucleolus, suppression of RECQ5 sensitizes tumor cells to the ATR inhibitor treatment. Collectively, this study reveals that RECQ5 plays a crucial role in pre-rRNA processing and ribosomal DNA (rDNA) stability.
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http://dx.doi.org/10.1093/nar/gkaf766 | DOI Listing |
HIV-1 particle assembly depends critically on multiple proteolytic cleavages of viral polyproteins by the viral protease, PR. PR is translated as part of the Gag-Pro-Pol polyprotein, which undergoes autoproteolysis to liberate active, dimeric PR during virus particle maturation. Gag-Pro-Pol is produced via an infrequent -1 frameshifting event in ribosomes translating full length genomic RNA as Gag mRNA.
View Article and Find Full Text PDFJ Biol Chem
September 2025
Department of Basic Medicine, College of Medicine, Jiaxing University, 118 Jiahang Road, Jiaxing 314001, Zhejiang, P. R. China; Provincial Key Laboratory of Multimodal Perceiving and Intelligent Systems,Jiaxing University,Jiaxing,314001, China; Engineering Research Center of Intelligent Human Health
The nucleolus is an important nonmembranous organelle within the nucleus and is responsible for ribosome biogenesis. This process is frequently upregulated in tumors to support elevated protein synthesis and sustain tumor growth. The transcription of rDNA into pre-45S rRNA, a rate-limiting step in ribosomal biogenesis, has been reported to be enhanced to drive the progression of non-small cell lung cancer (NSCLC).
View Article and Find Full Text PDFNucleic Acids Res
August 2025
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland.
An evolutionarily conserved ribosomal protein Rps29/uS14 participates in the assembly of late pre-40S particles. In yeast Saccharomyces cerevisiae, duplicate genes RPS29A and RPS29B encode two paralogous proteins with 91% sequence identity. Here, we report that loss of either paralog impairs final step of cytoplasmic processing of 20S pre-rRNA, which is a direct precursor of mature 18S ribosomal RNA (rRNA)-a component of small ribosomal subunit.
View Article and Find Full Text PDFFront Cell Infect Microbiol
August 2025
Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Objective: This study aimed to establish a multiplex molecular point-of-care assay called incorporating an ultra-fast sample pre-treatment for direct identification of complex (MTBC) and 8 non-tuberculous Mycobacteria (NTM) commonly prioritized in clinical settings, and to evaluate its performance in 149 clinical confirmed mycobacterial-positive samples.
Methods: The study was divided into two stages: a pilot study to establish the methodology and a clinical validation study to evaluate its performance. In the pilot study, we established the and analyzed its performance regarding limits of detection, reproducibility, specificity and efficiency.
EMBO Rep
August 2025
URPHYM-GEMO, NARILIS, University of Namur, Namur, Belgium.
Small nucleolar RNAs (snoRNAs) are a class of eukaryotic non-coding RNA molecules whose precursor transcripts are capped and polyadenylated. However, these end modifications are detrimental to snoRNA function and must be removed, a process typically involving excision from introns and/or endonucleolytic cleavage. For RNA precursors that host multiple snoRNAs, the sequence of maturation events is potentially important, but not well understood.
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