Regulation of gene expression during infection of the thermophilic bacterium Thermus thermophilus HB8 with the bacteriophage P23-45 was investigated. Macroarray analysis revealed host transcription shut-off and identified three temporal classes of phage genes; early, middle and late. Primer extension experiments revealed that the 5' ends of P23-45 early transcripts are preceded by a common sequence motif that likely defines early viral promoters. T. thermophilus HB8 RNA polymerase (RNAP) recognizes middle and late phage promoters in vitro but does not recognize early promoters. In vivo experiments revealed the presence of rifampicin-resistant RNA polymerizing activity in infected cells responsible for early transcription. The product of the P23-45 early gene 64 shows a distant sequence similarity with the largest, catalytic subunits of multisubunit RNAPs and contains the conserved metal-binding motif that is diagnostic of these proteins. We hypothesize that ORF64 encodes rifampicin-resistant phage RNAP that recognizes early phage promoters. Affinity isolation of T. thermophilus HB8 RNAP from P23-45-infected cells identified two phage-encoded proteins, gp39 and gp76, that bind the host RNAP and inhibit in vitro transcription from host promoters, but not from middle or late phage promoters, and may thus control the shift from host to viral gene expression during infection. To our knowledge, gp39 and gp76 are the first characterized bacterial RNAP-binding proteins encoded by a thermophilic phage.
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http://dx.doi.org/10.1016/j.jmb.2010.10.049 | DOI Listing |
Front Biosci (Landmark Ed)
January 2025
Department of Otolaryngology, Head and Neck Surgery, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, 330006 Nanchang, Jiangxi, China.
Background: It has been reported the therapeutic effects of mesenchymal stem cells (MSCs) on hearing loss. This study explored the therapeutic effects of growth differentiation factor 6 (GDF6) overexpression-induced MSCs (MSCs-GDF6) on age-related hearing loss (ARHL) and its underlying mechanisms.
Methods: Reverse transcription-quantitative PCR and western blotting were used to evaluate gene expression.
Front Biosci (Landmark Ed)
January 2025
Department of Cardiothoracic Surgery, The Affiliated Jiangyin Hospital of Nantong University, 214400 Jiangyin, Jiangsu, China.
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Methods: Differentially expressed genes between ESCC mouse oesophageal cancer tissues and normal tissues were analysed via RNA-seq; among them, SENP5 expression was upregulated, and this gene was selected for further analysis. Immunohistochemistry and western blotting were then used to validate the increased protein level of SENP5 in both mouse and human ESCC samples.
Front Biosci (Landmark Ed)
January 2025
Division of Molecular Psychiatry, Center of Mental Health, University of Hospital Würzburg, 97080 Würzburg, Germany.
Background: The inheritance of the short allele, encoding the serotonin transporter (SERT) in humans, increases susceptibility to neuropsychiatric and metabolic disorders, with aging and female sex further exacerbating these conditions. Both central and peripheral mechanisms of the compromised serotonin (5-HT) system play crucial roles in this context. Previous studies on SERT-deficient (Sert) mice, which model human SERT deficiency, have demonstrated emotional and metabolic disturbances, exacerbated by exposure to a high-fat Western diet (WD).
View Article and Find Full Text PDFFront Biosci (Landmark Ed)
January 2025
Department of Chemoradiotherapy, Ningbo No 2 Hospital, 315000 Ningbo, Zhejiang, China.
Background: Breast cancer stem cells (BCSCs) are instrumental in treatment resistance, recurrence, and metastasis. The development of breast cancer and radiation sensitivity is intimately pertinent to long non-coding RNA (lncRNA). This work is formulated to investigate how the lncRNA affects the stemness and radioresistance of BCSCs.
View Article and Find Full Text PDFPharm Biol
December 2025
The Affiliated Hospital, Changchun University of Chinese Medicine, Changchun, China.
Context: The decline in ovarian reserve is a major concern in female reproductive health, often associated with oxidative stress and mitochondrial dysfunction. Although ginsenoside Rg1 is known to modulate mitophagy, its effectiveness in mitigating ovarian reserve decline remains unclear.
Objective: To investigate the role of ginsenoside Rg1 in promoting mitophagy to preserve ovarian reserve.
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