Attenuation of loop-receptor interactions with pseudoknot formation

RNA tetraloops can recognize receptors to mediate long-range interactions in stable natural RNAs. In vitro selected GNRA tetraloop/receptor interactions are usually more ‘G/C-rich’ than their ‘A/U-rich’ natural counterparts. They are not as widespread in nature despite comparable biophysical and chemical properties. Moreover, while AA, AC and GU dinucleotide platforms occur in natural GAAA/11 nt receptors, the AA platform is somewhat preferred to the others. The apparent preference for ‘A/U-rich’ GNRA/receptor interactions in nature might stem from an evolutionary adaptation to avoid folding traps at the level of the larger molecular context. To provide evidences in favor of this hypothesis, several riboswitches based on natural and artificial GNRA receptors were investigated in vitro for their ability to prevent inter-molecular GNRA/receptor interactions by trapping the receptor sequence into an alternative intra-molecular pseudoknot. Extent of attenuation determined by native gel-shift assays and co-transcriptional assembly is correlated to the G/C content of the GNRA receptor. Our results shed light on the structural evolution of natural long-range interactions and provide design principles for RNA-based attenuator devices to be used in synthetic biology and RNA nanobiotechnology

Learning from adversity: What the COVID-19 pandemic can teach us about family resiliency

The present study aimed to characterize the immediate impacts of the COVID-19 pandemic on families with preschool age children and to identify pre-pandemic factors that explained unique family experiences. We leveraged an ongoing longitudinal study of relatively well-resourced community families who had reported on family functioning prior to the pandemic and completed surveys 6 months after pandemic onset. Both parents of dual parenting households endorsed significant hardships as a direct result of the pandemic (e.g., disrupted family routines, challenges at work); however, families also reported aspects of flourishing (i.e., experiencing positive outcomes in response to adversity) such as spending more time together as a family. Families were prone to greater hardships and fewer opportunities for growth to the extent that parents were lower in psychological resources (i.e., greater stress and internalizing symptoms, poor well-being) and were not on the same page as a couple (i.e., interparental discord, low quality coparenting) prior to pandemic onset. Finally, greater pandemic hardships predicted poorer parental mental health, greater family dysfunction, and elevated child psychopathology, controlling for pre-pandemic levels. Parents who reported more family flourishing from the pandemic had a stronger interparental relationship. Results are intended to inform theories of family stress and family interventions that can be tailored to promote resiliency (i.e., adaptation to challenging life events) and prevent dysfunction when families face rapid change and adjustment and high degrees of uncertainty and stress