An RNA pseudoknot stimulates HTLV-1 pro-pol programmed -1 ribosomal frameshifting.

Programmed -1 ribosomal frameshifts (-1 PRFs) are commonly used by viruses to regulate their enzymatic and structural protein levels. Human T-cell leukemia virus type 1 (HTLV-1) is a carcinogenic retrovirus that uses two independent -1 PRFs to express viral enzymes critical to establishing new HTLV-1 infections. How the cis-acting RNA elements in this viral transcript function to induce frameshifting is unknown. The objective of this work was to conclusively define the 3' boundary of and the RNA elements within the HTLV-1 pro-pol frameshift site. We hypothesized that the frameshift site structure was a pseudoknot and that its 3' boundary would be defined by the pseudoknot's 3' end. To test these hypotheses, the in vitro frameshift efficiencies of three HTLV-1 pro-pol frameshift sites with different 3' boundaries were quantified. The results indicated that nucleotides included in the longest construct were essential to highly efficient frameshift stimulation. Interestingly, only this construct could form the putative frameshift site pseudoknot. Next, the secondary structure of this frameshift site was determined. The dominant structure was an H-type pseudoknot which, together with the slippery sequence, stimulated frameshifting to 19.4(±0.3)%. The pseudoknot's critical role in frameshift stimulation was directly revealed by examining the impact of structural changes on HTLV-1 pro-pol -1 PRF. As predicted, mutations that occluded pseudoknot formation drastically reduced the frameshift efficiency. These results are significant because they demonstrate that a pseudoknot is important to HTLV-1 pro-pol -1 PRF and define the frameshift site's 3' boundary.

E-cigarette environmental and fire/life safety risks in schools reported by secondary school teachers.

BACKGROUND: To identify if e-cigarette usage is an on-campus problem for secondary schools and evaluate initial school survey responses. More specifically, this survey can aid in identifying where students are seen using e-cigarettes, if smoke alarms have been newly inserted on school property, if smoke alarms have been tampered with to allow for vaping without detection; and, if any e-cigarette fires or explosions have occurred on school property. METHODS: This survey, disseminated to New Jersey secondary school teachers across seven sessions January-July 2019, resulted in 104 complete responses of 109 respondents. The survey was conducted after fire prevention, exit/egress, and life safety portions of "OSHA 10 Plus for General Industry" courses. Survey questions included number of times teachers observed students vaping and location where vaping in last 12 months, fire alarm installation and tampering, and fires or explosions and injuries from vaping/e-cigarette devices. RESULTS: Many (63%) respondents reported very or moderately common rates of vaping within their schools; however, three of four questions regarding school fire and smoke alarm use specifically to detect vaping had a majority of unsure/I don't know responses. CONCLUSION: Results suggested concerns regarding student vaping and e-cigarette use inside and outside secondary schools. Improved school detection and response are warranted. TRIAL REGISTRATION: Not applicable.

Isoform-specific roles for AKT in affective behavior, spatial memory, and extinction related to psychiatric disorders.

AKT is implicated in neurological disorders. AKT has three isoforms, AKT1/AKT2/AKT3, with brain cell type-specific expression that may differentially influence behavior. Therefore, we examined single Akt isoform, conditional brain-specific Akt1, and double Akt1/3 mutant mice in behaviors relevant to neuropsychiatric disorders. Because sex is a determinant of these disorders but poorly understood, sex was an experimental variable in our design. Our studies revealed AKT isoform- and sex-specific effects on anxiety, spatial and contextual memory, and fear extinction. In Akt1 mutant males, viral-mediated AKT1 restoration in the prefrontal cortex rescued extinction phenotypes. We identified a novel role for AKT2 and overlapping roles for AKT1 and AKT3 in long-term memory. Finally, we found that sex-specific behavior effects were not mediated by AKT expression or activation differences between sexes. These results highlight sex as a biological variable and isoform- or cell type-specific AKT signaling as potential targets for improving treatment of neuropsychiatric disorders.