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Jeremy Reins wakes up in a cramped space with the only light coming from the digital numbers ticking away above his head. Confused and disoriented with no one answering his cries for help, he suddenly hears an engine rev and his predicament becomes clear: he's trapped in the trunk of a moving car. As his captors reveal themselves, Jeremy realizes he won't be set free until he gives up the whereabouts of a secret location where the U.S. President is taken in the event of a terrorist attack.

Many bacteria are able to survive in the presence of antibiotics in part because they possess pumps that can remove a broad range of small molecules; here, the structure of one such pump, AcrAB–TolC, is determined using X-ray crystallography and cryo-electron microscopy. AcrAB–TolC efflux pump structure Many bacteria are able to survive in the presence of antibiotics and other toxic compounds because they possess versatile energy-dependent transmembrane pumps. For example, the AcrAB–TolC efflux pump, which spans the inner and outer membranes of the bacterium, is able to transport a broad range of structurally unrelated small molecules/drugs out of some Gram-negative bacteria. The pump is comprised of an outer-membrane channel (TolC), a secondary transporter (AcrB; located in the inner membrane), and AcrA, a periplasmic protein that acts as a bridge for these two integral membrane proteins. In this paper, the authors solve an X-ray crystal structure of AcrB bound to AcrZ (a small protein that appears to alter the substrate preferences of AcrB) and a cryo-EM structure of the entire 771 kDa efflux pump. The capacity of numerous bacterial species to tolerate antibiotics and other toxic compounds arises in part from the activity of energy-dependent transporters. In Gram-negative bacteria, many of these transporters form multicomponent ‘pumps’ that span both inner and outer membranes and are driven energetically by a primary or secondary transporter component 1 , 2 , 3 , 4 , 5 , 6 , 7 . A model system for such a pump is the acridine resistance complex of Escherichia coli 1 . This pump assembly comprises the outer-membrane channel TolC, the secondary transporter AcrB located in the inner membrane, and the periplasmic AcrA, which bridges these two integral membrane proteins. The AcrAB–TolC efflux pump is able to transport vectorially a diverse array of compounds with little chemical similarity, thus conferring resistance to a broad spectrum of antibiotics. Homologous complexes are found in many Gram-negative species, including in animal and plant pathogens. Crystal structures are available for the individual components of the pump 2 , 3 , 4 , 5 , 6 , 7 and have provided insights into substrate recognition, energy coupling and the transduction of conformational changes associated with the transport process. However, how the subunits are organized in the pump, their stoichiometry and the details of their interactions are not known. Here we present the pseudo-atomic structure of a complete multidrug efflux pump in complex with a modulatory protein partner 8 from E. coli . The model defines the quaternary organization of the pump, identifies key domain interactions, and suggests a cooperative process for channel assembly and opening. These findings illuminate the basis for drug resistance in numerous pathogenic bacterial species.

Ribosomes stall when they encounter the end of messenger RNA (mRNA) without an in-frame stop codon. In bacteria, these \"nonstop\" complexes can be rescued by alternative ribosome-rescue factor A (ArfA). We used electron cryomicroscopy to determine structures of ArfA bound to the ribosome with 3'-truncated mRNA, at resolutions ranging from 3.0 to 3.4 angstroms. ArfA binds within the ribosomal mRNA channel and substitutes for the absent stop codon in the A site by specifically recruiting release factor 2 (RF2), initially in a compact preaccommodated state. A similar conformation of RF2 may occur on stop codons, suggesting a general mechanism for release-factor-mediated translational termination in which a conformational switch leads to peptide release only when the appropriate signal is present in the A site.

Facial nerve (FN) injury can lead to debilitating and permanent facial paresis/paralysis (FP), where facial muscles progressively lose tone, atrophy, and ultimately reduce to scar tissue. Despite considerable efforts in the recent decades, therapies for FP still possess high failure rates and provide inadequate recovery of muscle function. In this pilot study, we used a feline model to demonstrate the potential for chronically implanted multichannel dual-cuff electrodes (MCE) to selectively stimulate injured facial nerves at low current intensities to avoid stimulus-induced neural injury. Selective facial muscle activation was achieved over six months after FN injury and MCE implantation in two domestic shorthaired cats (Felis catus). Through utilization of bipolar stimulation, specific muscles were activated at significantly lower electrical currents than was achievable with single channel stimulation. Moreover, interval increases in subthreshold current intensities using bipolar stimulation enabled a graded EMG voltage response while maintaining muscle selectivity. Histological examination of neural tissue at implant sites showed no appreciable signs of stimulation-induced nerve injury. Thus, by selectively activating facial musculature six months following initial FN injury and MCE implantation, we demonstrated the potential for our neural stimulator system to be safely and effectively applied to the chronic setting, with implications for FP treatment.

Many bacteria are able to survive in the presence of antibiotics in part because they possess pumps that can remove a broad range of small molecules; here, the structure of one such pump, AcrAB-TolC, is determined using X-ray crystallography and cryo-electron microscopy.

Although costly to maintain, protein homeostasis is indispensable for normal cellular function and long-term health. In mammalian cells and tissues, daily variation in global protein synthesis has been observed, but its utility and consequences for proteome integrity are not fully understood. Using several different pulse-labelling strategies, here we gain direct insight into the relationship between protein synthesis and abundance proteome-wide. We show that protein degradation varies in-phase with protein synthesis, facilitating rhythms in turnover rather than abundance. This results in daily consolidation of proteome renewal whilst minimising changes in composition. Coupled rhythms in synthesis and turnover are especially salient to the assembly of macromolecular protein complexes, particularly the ribosome, the most abundant species of complex in the cell. Daily turnover and proteasomal degradation rhythms render cells and mice more sensitive to proteotoxic stress at specific times of day, potentially contributing to daily rhythms in the efficacy of proteasomal inhibitors against cancer. Our findings suggest that circadian rhythms function to minimise the bioenergetic cost of protein homeostasis through temporal consolidation of protein turnover.Competing Interest StatementThe authors have declared no competing interest.Footnotes* Significant textural changes. Figure 5 added.

Early mammals were nocturnal until the Cretaceous-Paleogene extinction enabled diurnal niche expansion. Diurnality evolved multiple times independently, but the mechanisms driving this shift remain unclear. We identify a conserved cell-intrinsic signal inversion that facilitates the transition from nocturnality to diurnality. Diurnal and nocturnal mammalian cells respond oppositely to temperature and osmotic cycles, mirroring species’ activity patterns. Cells exhibit differential global responses to temperature changes, including the phosphoproteome and protein synthesis. mTOR signaling is identified as a central mediator of this inversion, with diurnal mammals converging on modifications to mTOR and WNK pathways during evolution. Reducing mTOR activity induces nocturnal-to-diurnal shifting at cellular, tissue, and organismal levels. Therefore, the mTOR pathway is a cellular nexus that integrates energetic state and environmental signals to determine activity niche.

Without good credit and specifically being without major credit cards makes one a financial second-class citizen in America. Sad but it is true. However, there are several relatively simple things the average person can do to 1) Get credit if they do not already have it; 2) Expand their credit and 3) Repair their credit if it has become negative.