Autogenous regulation is a general strategy of balancing ribosomal protein synthesis in bacteria. Control mechanisms have been studied in detail for most of ribosomal protein operons, except for rpsB-tsf encoding essential r-protein S2 and elongation factor Ts, where even the promoter has remained unknown. By using single-copy translational fusions with the chromosomal lacZ gene and Western-blot analysis, we demonstrate here that S2 serves as a negative regulator of both rpsB and tsf expression in vivo, acting at a single target within the rpsB 5'-untranslated region (5'-UTR). As determined by primer extension, transcription of the Escherichia coli rpsB-tsf operon starts 162 nucleotides upstream of the rpsB initiation codon at a single promoter TGTGGTATAAA belonging to the extended -10 promoter class. Both the promoter signature and the 5'-UTR structure of the rpsB gene appear to be highly conserved in gamma-proteobacteria. Deletion analysis of the rpsB 5'-UTR within rpsB'-'lacZ fusions has revealed that an operator region involved in the S2 autoregulation comprises conserved structural elements located upstream of the rpsB ribosome binding site. The S2-mediated autogenous control is impaired in rpsB mutants and, more surprisingly, in the rpsA mutant producing decreased amounts of truncated r-protein S1 (rpsAIS10), indicating that S2 might act as a repressor in cooperation with S1.
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http://dx.doi.org/10.1261/rna.1099108 | DOI Listing |
Clin Transl Oncol
January 2025
Inflammation and Cancer Biology Laboratory, Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, 784028, India.
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View Article and Find Full Text PDFNucleic Acids Res
January 2025
Central European Institute of Technology, Masaryk University, Kamenice 5, Brno 625 00, Czech Republic.
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View Article and Find Full Text PDFCancer Biol Ther
December 2025
State Key Laboratory of Cancer Biology, Department of Pathology, Xijing Hospital, Air Force Military Medical University, Xi'an, China.
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View Article and Find Full Text PDFInt J Mol Sci
January 2025
Institute of Pathogenic Microorganism, Jiangxi Agricultural University, Nanchang 330000, China.
Monkeypox (MPOX) is a zoonotic viral disease caused by the Monkeypox virus (MPXV), which has become the most significant public health threat within the genus since the eradication of the Variola virus (VARV). Despite the extensive attention MPXV has garnered, little is known about its clinical manifestations in humans. In this study, a high-throughput RNA sequencing (RNA-seq) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach was employed to investigate the transcriptional and metabolic responses of HEK293T cells to the MPXV A5L protein.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Division of Cancer, Department of Surgery & Cancer, Faculty of Medicine, Imperial College London, London W12 0NN, UK.
S6 Kinase 2 (S6K2) is a key regulator of cellular signaling and is crucial for cell growth, proliferation, and survival. This review is divided into two parts: the first focuses on the complex network of upstream effectors, downstream modulators, and post-translational modifications (PTMs) that regulate S6K2 activity. We emphasize the dynamic nature of S6K2 regulation, highlighting its critical role in cellular homeostasis and its potential as a therapeutic target in diseases like cancer.
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