Porcine reproductive and respiratory syndrome virus (PRRSV) is a devastating pathogen in the swine industry worldwide. miRNAs are reported to be involved in virus-host interaction. Here, we used high-throughput sequencing and miRNA inhibitors to screen possible miRNAs that can inhibit PRRSV infection on its target cell, porcine alveolar macrophages. We observed that miR-218 was downregulated upon virus infection, and knockdown of miR-218 significantly enhanced PRRSV replication. Overexpression of miR-218 resulted in a decrease in PRRSV replication, and this overexpression did not alter viral genomic RNA levels, but rather increased antiviral interferon signaling. Further analysis revealed that miR-218 regulated PRRSV replication by directly targeting porcine suppressor of cytokine signaling 3 (SOCS3), a JAK2 kinase inhibitor. Knockdown of the endogenous SOCS3 expression led to augmentation of type I interferon genes and resulted in decreased PRRSV replication, and vice versa. During PRRSV infection in vivo and in vitro, cellular miR-218 expression was downregulated and SOCS3 expression was upregulated, further supporting the inverse correlation between miR-218 and SOCS3 expression. The data on SOCS3 depletion in combination with miR-218 inhibition suggested that the antiviral activity of miR-218 required the SOCS3-mediated signaling pathway. Similarly, miR-218 negatively regulated PRRSV replication in Marc-145 cells, as well as the replication of porcine epidemic diarrhea virus and transmissible gastroenteritis virus in Vero and ST cells respectively. Taken together, these results demonstrate that PRRSV-induced miR-218 downregulation serves to inhibit the type I interferon response and may provide a novel therapeutic target for treatment of PRRSV and other viral infections.MtsZ is a molybdenum-containing methionine sulfoxide reductase that supports virulence in the human respiratory pathogen Haemophilus influenzae (Hi). HiMtsZ belongs to a group of structurally and spectroscopically uncharacterized S-/N-oxide reductases, all of which are found in bacterial pathogens. Here, we have solved the crystal structure of HiMtsZ, which reveals that the HiMtsZ substrate-binding site encompasses a previously unrecognized part that accommodates the methionine sulfoxide side chain via interaction with His182 and Arg166. Charge and amino acid composition of this side chain-binding region vary and, as indicated by electrochemical, kinetic, and docking studies, could explain the diverse substrate specificity seen in closely related enzymes of this type. The HiMtsZ Mo active site has an underlying structural flexibility, where dissociation of the central Ser187 ligand affected catalysis at low pH. Unexpectedly, the two main HiMtsZ electron paramagnetic resonance (EPR) species resembled not only a related dimethyl sulfoxide reductase but also a structurally unrelated nitrate reductase that possesses an Asp-Mo ligand. This suggests that contrary to current views, the geometry of the Mo center and its primary ligands, rather than the specific amino acid environment, is the main determinant of the EPR properties of mononuclear Mo enzymes. The flexibility in the electronic structure of the Mo centers is also apparent in two of three HiMtsZ EPR-active Mo(V) species being catalytically incompetent off-pathway forms that could not be fully oxidized.Accurate translation termination in bacteria requires correct recognition of the stop codons by the class-I release factors (RFs) RF1 and RF2, which release the nascent peptide from the peptidyl tRNA after undergoing a "compact to open" conformational transition. These RFs possess a conserved Gly-Gly-Gln (GGQ) peptide release motif, of which the Q residue is posttranslationally methylated. Tanespimycin price GGQ-methylated RFs have been shown to be faster in peptide release than the unmethylated ones, but it was unknown whether this modification had additional roles. Using a fluorescence-based real-time in vitro translation termination assay in a stopped-flow instrument, we demonstrate that methylated RF1 and RF2 are two- to four-fold more accurate in the cognate stop codon recognition than their unmethylated variants. Using pH titration, we show that the lack of GGQ methylation facilitates the "compact to open" transition, which results in compromised accuracy of the unmethylated RFs. Furthermore, thermal melting studies using circular dichroism and SYPRO-orange fluorescence demonstrate that GGQ methylation increases overall stability of the RF proteins. This increased stability, we suspect, is the basis for the more controlled conformational change of the methylated RFs upon codon recognition, which enhances both their speed and accuracy. This GGQ methylation-based modulation of the accuracy of RFs can be a tool for regulating translational termination in vivo.A year ago, when I first contemplated writing this article, my intent was to provide a detailed review of the contributions of the diverse community of talented scientists in my lab to the nuclear receptor research field. In the throes of a deadly pandemic, political turmoil, and Black Lives Matter, however, I found myself compelled to tell a more personal story. While I will still cover milestones in our understanding of the intracellular trafficking of the thyroid hormone receptor, now these will be set against the backdrop of my path as a woman in STEM and on being intentionally inclusive. By sharing reflections on my journey, I hope to encourage young investigators to persist in their pursuit of a career in science.In the workplace, sit-stand workstations are being installed to reduce excessive sitting time and the consequent risk factors for cardiovascular ailments (e.g., postprandial hyperglycemia). However, a prolonged standing posture also has detrimental effects in terms of musculoskeletal symptoms and work efficiency. We thus investigated whether alternating between a sitting and standing work posture improves postprandial glucose response and computer task performance. Nine healthy young males completed 4 × 20-min computer tasks in the early afternoon (i.e., 30 min after eating lunch) under three different work conditions, had no change in posture (only sitting=the control trial, CON), and engaged in two styles of alternating between sitting and standing every 20 min (sitting → standing → sitting → standing, SIT-STAND; standing → sitting → standing → sitting, STAND-SIT). For the computer tasks, all participants had to subtract a two-digit number from a four-digit number and to input the answer in the answer column on the computer.