Maoto, a Traditional Japanese Herbal Medicine, Inhibits Uncoating of Influenza Virus

We previously reported in randomized controlled trials that maoto, a traditional herbal medicine, showed clinical and virological efficacy for seasonal influenza. In this study, a culturing system for influenza was used to test the effect of maoto. A549 cells in the culture were infected with influenza virus A (PR8) and followed after treatment with maoto; the virus titers in the culture supernatant, intracellular viral proteins, and viral RNA were determined. When infected cells were cultured with maoto for 24 hr, the virus titer and protein were significantly reduced compared with medium only. Other subtypes, A/H3N2, H1N1pdm, and B, were also inhibited by maoto. Proliferation of viral RNA in a 6 hr culture was inhibited by maoto in the early phase, especially in the first 30 min. Focusing on the entry step of the influenza virus, we found that endosomal pH, regulated by vacuolar-type H+ ATPase (V-ATPase) located in the membrane, was increased when treated with maoto. We also found that uncoating of influenza viruses was also inhibited by maoto, resulting in the increase of the number of virus particles in endosomes. These results strongly suggest that the inhibition of endosomal acidification by maoto results in blocking influenza virus entry to cytoplasm, probably through the inhibition of V-ATPase. The present study provides evidence that supports the clinical use of maoto for the treatment of influenza

Coupling of Rotation and Catalysis in F1-ATPase Revealed by Single-Molecule Imaging and Manipulation

SummaryF1-ATPase is a rotary molecular motor that proceeds in 120° steps, each driven by ATP hydrolysis. How the chemical reactions that occur in three catalytic sites are coupled to mechanical rotation is the central question. Here, we show by high-speed imaging of rotation in single molecules of F1 that phosphate release drives the last 40° of the 120° step, and that the 40° rotation accompanies reduction of the affinity for phosphate. We also show, by single-molecule imaging of a fluorescent ATP analog Cy3-ATP while F1 is forced to rotate slowly, that release of Cy3-ADP occurs at ∼240° after it is bound as Cy3-ATP at 0°. This and other results suggest that the affinity for ADP also decreases with rotation, and thus ADP release contributes part of energy for rotation. Together with previous results, the coupling scheme is now basically complete

Stimulated raman scattering microscope with shot noise limited sensitivity using subharmonically synchronized laser pulses

Ozeki Y., Kitagawa Y., Sumimura K., et al. Stimulated raman scattering microscope with shot noise limited sensitivity using subharmonically synchronized laser pulses. Optics Express, 18, 13, 13708. https://doi.org/10.1364/OE.18.013708

Label-free observation of tissues by high-speed stimulated Raman spectral microscopy and independent component analysis

SPIE BiOS, 2013, San Francisco, California, United StatesYasuyuki Ozeki, Yoichi Otsuka, Shuya Sato, Hiroyuki Hashimoto, Wataru Umemura, Kazuhiko Sumimura, Norihiko Nishizawa, Kiichi Fukui, Kazuyoshi Itoh, "Label-free observation of tissues by high-speed stimulated Raman spectral microscopy and independent component analysis," Proc. SPIE 8588, Multiphoton Microscopy in the Biomedical Sciences XIII, 858806 (22 February 2013); https://doi.org/10.1117/12.200277

Neither Helix in the Coiled Coil Region of the Axle of F1-ATPase Plays a Significant Role in Torque Production

F1-ATPase is an ATP-driven rotary molecular motor in which the central γ-subunit rotates inside the cylinder made of α3β3 subunits. The amino and carboxy termini of the γ-subunit form the axle, an α-helical coiled coil that deeply penetrates the stator cylinder. We previously truncated the axle step by step, starting with the longer carboxy terminus and then cutting both termini at the same levels, resulting in a slower yet considerably powerful rotation. Here we examine the role of each helix by truncating only the carboxy terminus by 25–40 amino-acid residues. Longer truncation impaired the stability of the motor complex severely: 40 deletions failed to yield rotating the complex. Up to 36 deletions, however, the mutants produced an apparent torque at nearly half of the wild-type torque, independent of truncation length. Time-averaged rotary speeds were low because of load-dependent stumbling at 120° intervals, even with saturating ATP. Comparison with our previous work indicates that half the normal torque is produced at the orifice of the stator. The very tip of the carboxy terminus adds the other half, whereas neither helix in the middle of the axle contributes much to torque generation and the rapid progress of catalysis. None of the residues of the entire axle played a specific decisive role in rotation

Fertilization controls tiller numbers via transcriptional regulation of a MAX1-like gene in rice cultivation

低施肥でも穂数が減らず、収量を確保できるイネを開発 --ゲノム編集技術で、SDGs時代の新しいイネ遺伝資源を創成--. 京都大学プレスリリース. 2023-06-13.Fertilization controls various aspects of cereal growth such as tiller number, leaf size, and panicle size. However, despite such benefits, global chemical fertilizer use must be reduced to achieve sustainable agriculture. Here, based on field transcriptome data from leaf samples collected during rice cultivation, we identify fertilizer responsive genes and focus on Os1900, a gene orthologous to Arabidopsis thaliana MAX1, which is involved in strigolactone biosynthesis. Elaborate genetic and biochemical analyses using CRISPR/Cas9 mutants reveal that Os1900 together with another MAX1-like gene, Os5100, play a critical role in controlling the conversion of carlactone into carlactonoic acid during strigolactone biosynthesis and tillering in rice. Detailed analyses of a series of Os1900 promoter deletion mutations suggest that fertilization controls tiller number in rice through transcriptional regulation of Os1900, and that a few promoter mutations alone can increase tiller numbers and grain yields even under minor-fertilizer conditions, whereas a single defective os1900 mutation does not increase tillers under normal fertilizer condition. Such Os1900 promoter mutations have potential uses in breeding programs for sustainable rice production