PRMT-7/PRMT7 activates HLH-30/TFEB to guard plasma membrane integrity compromised by bacterial pore-forming toxins.

Bacterial pore-forming toxins (PFTs) that disrupt host plasma membrane integrity (PMI) significantly contribute to the virulence of various pathogens. However, how host cells protect PMI in response to PFT perforation in vivo remains obscure. Previously, we demonstrated that the HLH-30/TFEB-dependent intrinsic cellular defense (INCED) is elicited by PFT to maintain PMI in Caenorhabditis elegans intestinal epithelium. Yet, the molecular mechanism for the full activation of HLH-30/TFEB by PFT remains elusive. Here, we reveal that PRMT-7 (protein arginine methyltransferase-7) is indispensable to the nuclear transactivation of HLH-30 elicited by PFTs. We demonstrate that PRMT-7 participates in the methylation of HLH-30 on its RAG complex binding domain to facilitate its nuclear localization and activation. Moreover, we showed that PRMT7 is evolutionarily conserved to regulate TFEB cellular localization and repair plasma damage caused by PFTs in human intestinal cells. Together, our observations not only unveil a novel PRMT-7/PRMT7-dependent post-translational regulation of HLH-30/TFEB but also shed insight on the evolutionarily conserved mechanism of the INCED against PFT in metazoans.

Direct geometric probe of singularities in band structure.

A quantum system's energy landscape may have points where multiple energy surfaces are degenerate and that exhibit singular geometry of the wave function manifold, with major consequences for the system's properties. Ultracold atoms in optical lattices have been used to indirectly characterize such points in the band structure. We measured the non-Abelian transformation produced by transport directly through the singularities. We accelerated atoms along a quasi-momentum trajectory that enters, turns, and then exits the singularities at linear and quadratic band-touching points of a honeycomb lattice. Measurements after transport identified the topological winding numbers of these singularities to be 1 and 2, respectively. Our work introduces a distinct method for probing singularities that enables the study of non-Dirac singularities in ultracold-atom quantum simulators.

Interaction-Enhanced Group Velocity of Bosons in the Flat Band of an Optical Kagome Lattice.

Geometric frustration of particle motion in a kagome lattice causes the single-particle band structure to have a flat s-orbital band. We probe this band structure by placing a Bose-Einstein condensate into excited Bloch states of an optical kagome lattice, and then measuring the group velocity through the atomic momentum distribution. We find that interactions renormalize the band structure, greatly increasing the dispersion of the third band, which is nearly non-dispersing the single-particle treatment. Calculations based on the lattice Gross-Pitaevskii equation indicate that band structure renormalization is caused by the distortion of the overall lattice potential away from the kagome geometry by interactions.

Approach strategy and working posture in manual hand tool operation.

The strategy for approaching a manual work position is an important reference for describing a goal-directed task. However, knowledge on this aspect of human behavior is scarce. The objectives of this study are twofold: (1) to describe and understand the strategy people tend to adopt for approaching a manual work position from different directions when their initial standing position is three meters away, and (2) to describe the working posture they tend to adopt when operating a pistol-grip hand tool at different heights. An experiment involving eight participants was conducted to measure the whole-body position and orientation when approaching a work position from five directions. The working posture adopted when operating a pistol-grip hand tool at six working heights was examined. The results indicate that the final whole-body position and orientation (while performing the operation) was affected significantly by the approach direction. A linear relationship between the approach direction and the final whole-body orientation was obtained. The participants adopted a strategy combining the work efficiency and comfort strategies. They deviated from the least-distance (straight line) walking path and re-oriented their whole body for the operation when approaching the work position. The working posture was significantly affected by the working height. The working postures at six working heights were established. The participants adopted a standing posture when the working height was between eye and hip height, and a stooping or squatting posture when operating at knee and ankle height. The results of this study can be used to enhance digital human modeling motion generated for human movement simulation.