The triplet metal-to-ligand charge transfer ((3)MLCT) dynamics of two structurally characterized Re(I)(CO)(3)(phen)(HisX)-modified (phen = 1,10-phenanthroline; X = 83, 109) Pseudomonas aeruginosa azurins have been investigated by picosecond time-resolved infrared (TRIR) spectroscopy in aqueous (D(2)O) solution. The (3)MLCT relaxation dynamics exhibited by the two Re(I)-azurins are very different from those of the sensitizer [Re(I)(CO)(3)(phen)(im)](+) (im = imidazole). Whereas the Re(I)(CO)(3) intramolecular vibrational relaxation in Re(I)(CO)(3)(phen)(HisX)Az (4 ps) is similar to that of [Re(I)(CO)(3)(phen)(im)](+) (2 ps), the medium relaxation is much slower ( approximately 250 vs 9.5 ps); the 250-ps relaxation is attributable to reorientation of D(2)O molecules as well as structural reorganization of the rhenium chromophore and nearby polar amino acids in each of the modified proteins.
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In Vitro Cell Dev Biol Anim
January 2025
Department of Outpatient Service, The Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, 421002, Hunan, China.
The objective of this study is to explore how adipose-derived stem cells (ASCs) regulate mitochondrial structure and function and the impact of this regulation on slowing cellular senescence. HFF-1 cells were induced by HO to establish a cellular senescence model, and ASCs or Mdivi-1 (mitochondrial fission inhibitor) was added. MTT examined the cell proliferation; flow cytometry detected mitochondrial membrane potential as well as apoptosis and cell cycle; kit measured ATP production; ELISA analyzed the levels of interleukin-6 (IL-6), interleukin 1 beta (IL-1β), tumor necrosis factor alpha-like (TNF-α), glutathione (GSH), malondialdehyde (MDA), and superoxide dismutase (SOD); Western blotting and qRT-PCR detected the expression of protein and mRNA levels; and β-galactosidase staining observed the degree of cellular senescence.
View Article and Find Full Text PDFNat Mater
January 2025
Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.
EMBO Rep
January 2025
Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, Fuzhou, China.
Cyclic diguanosine monophosphate (c-di-GMP) is a ubiquitous bacterial secondary messenger with diverse functions. A previous Escherichia coli proteome microarray identified that c-di-GMP binds to the 23S rRNA methyltransferases RlmI and RlmE. Here we show that c-di-GMP inhibits RlmI activity in rRNA methylation assays, and that it modulates ribosome assembly in the presence of kanamycin.
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January 2025
Medical Clinic III for Oncology, Hematology, Immuno-Oncology and Rheumatology, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.
Studying the human immune system in vivo is challenging and often not possible. Therefore, most human immunology studies have been predominantly confined to peripheral blood analyses, which by themselves have inherent limitations, as many immune reactions take place within tissues. For example, potent antibody responses that contribute to fighting infections and provide protection following vaccination require cellular interactions between B cells and T cells in specialized micro-anatomical structures called germinal centers, which are found in secondary lymphoid organs such as spleen, lymph nodes, and tonsils.
View Article and Find Full Text PDFNat Rev Genet
January 2025
Department of Molecular Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA, USA.
mRNA degradation pathways have key regulatory roles in gene expression. The intrinsic stability of mRNAs in the cytoplasm of eukaryotic cells varies widely in a gene- and isoform-dependent manner and can be regulated by cellular cues, such as kinase signalling, to control mRNA levels and spatiotemporal dynamics of gene expression. Moreover, specialized quality control pathways exist to rid cells of non-functional mRNAs produced by errors in mRNA processing or mRNA damage that negatively impact translation.
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