Functional implications of hexameric assembly of RraA proteins from Vibrio vulnificus

Association between personality traits and concerns about falling among older patients: the mediating role of subjective age

Background

Older patients are at high risk of falling, and regular assessments of their concerns about falling (CaF) are often recommended. The present study aimed to investigate the association between CaF and personality traits among older patients as well as to elucidate the mediating role of subjective age.

Method

A cross-sectional study was conducted among 407 patients aged over 60 years in a tertiary hospital located in Chengdu, Sichuan Province, from March 2023 to May 2023. Predesigned electronic questionnaires were distributed to collect relevant data. Four different models (both crude and adjusted weighted linear regression models) were constructed based on the confounders. Confounders were gradually put into the models to control for bias and to examine the stability of the correlations. Bootstrap sampling was employed to examine the mediating role of subjective age.

Result

According to the fully adjusted model, neuroticism (β = 0.17, 95% CI: 0.02 to 0.31, p for trend = 0.02), extraversion (β = -0.07, 95% CI: -0.15 to 0.001, p for trend = 0.05), and subjective age (β = 2.02, 95% CI: 1.28 to 2.78, p for trend <0.001) were consistently correlated with CaF. Mediating analysis revealed that extraversion was negatively related with CaF both directly and indirectly, via subjective age [23.2% partial effect, bootstrap 95%CI: -0.024(-0.080, -0.000)]. Higher neuroticism was consistently related to older subjective age (β = 0.002, 95% CI: 0.001 to 0.004, p for trend = 0.006), while higher levels of conscientiousness, openness, and extraversion were consistently correlated with younger subjective age(β = -0.002, p for trend = 0.04; β = -0.003, p for trend = 0.003; β = -0.002, p for trend = 0.0, respectively).

Conclusion

Extraversion and neuroticism were significantly correlated with CaF. Moreover, subjective age partially mediated the relationship between extraversion and CaF. Furthermore, subjective age was found to be associated with both CaF and personality traits. These findings highlighted the important roles of personality traits and subjective age in assessments of CaF and in the development of strategies for preventing falls among older patients.

Identification of the global regulatory roles of RraA via the integrative transcriptome and proteome in Vibrio alginolyticus

Bacterial ribonuclease E (RNase E) is vital for posttranscriptional regulation by degrading and processing RNA. The RraA protein inhibits RNase E activity through protein-protein interactions, exerting a global regulatory effect on gene expression. However, the specific role of RraA remains unclear. In this study, we investigated rraA expression in Vibrio alginolyticus ZJ-T and identified three promoters responsible for its expression, resulting in transcripts with varying 5'-UTR lengths. During the stationary phase, rraA was significantly posttranscriptionally inhibited. Deletion of rraA had no impact on bacterial growth in rich medium Luria-Bertani broth with salt (LBS) but resulted in decreased biofilm formation and increased resistance to polymyxin B. Transcriptome analysis revealed 350 differentially expressed genes (DEGs) between the wild type and the rraA mutant, while proteome analysis identified 267 differentially expressed proteins (DEPs). Integrative analysis identified 55 genes common to both DEGs and DEPs, suggesting that RraA primarily affects gene expression at the posttranscriptional level. KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis demonstrated that RraA facilitates the conversion of fatty acids, propionic acid, and branched-chain amino acids to acetyl-CoA while enhancing amino acid and peptide uptake. Notably, RraA positively regulates the expression of virulence-associated genes, including those involved in biofilm formation and the type VI secretion system. This study expands the understanding of the regulatory network of RraA through transcriptome analysis, emphasizing the importance of proteomic analysis in investigating posttranscriptional regulation.IMPORTANCERraA is an inhibitor protein of ribonuclease E that interacts with and suppresses its endonucleolytic activity, thereby playing a widespread regulatory role in the degradation and maturation of diverse mRNAs and noncoding small RNAs. However, the physiological functions and associated regulon of RraA in Vibrio alginolyticus have not been fully elucidated. Here, we report that RraA impacts virulence-associated physiological processes, namely, antibiotic resistance and biofilm formation, in V. alginolyticus. By conducting an integrative analysis of both the transcriptome and proteome, we revealed the involvement of RraA in carbon metabolism, amino acid catabolism, and transport, as well as in the type VI secretion system. Collectively, these findings elucidate the regulatory influence of RraA on multiple pathways associated with metabolism and pathogenesis in V. alginolyticus.

Regulator of ribonuclease activity modulates the pathogenicity of Vibrio vulnificus

RraA, a protein regulator of RNase E activity, plays a unique role in modulating the mRNA abundance in Escherichia coli. The marine pathogenic bacterium Vibrio vulnificus also possesses homologs of RNase E (VvRNase E) and RraA (VvRraA1 and VvRraA2). However, their physiological roles have not yet been investigated. In this study, we demonstrated that VvRraA1 expression levels affect the pathogenicity of V. vulnificus. Compared to the wild-type strain, the VvrraA1-deleted strain (ΔVvrraA1) showed decreased motility, invasiveness, biofilm formation ability as well as virulence in mice; these phenotypic changes of ΔVvrraA1 were restored by the exogenous expression of VvrraA1. Transcriptomic analysis indicated that VvRraA1 expression levels affect the abundance of a large number of mRNA species. Among them, the half-lives of mRNA species encoding virulence factors (e.g., smcR and htpG) that have been previously shown to affect VvrraA1 expression-dependent phenotypes were positively correlated with VvrraA1 expression levels. These findings suggest that VvRraA1 modulates the pathogenicity of V. vulnificus by regulating the abundance of a subset of mRNA species.

Heat Stress in Legume Seed Setting: Effects, Causes, and Future Prospects

Grain legumes provide a rich resource of plant nutrition to human diets and are vital for food security and sustainable cropping. Heat stress during flowering has a detrimental effect on legume seed yield, mainly due to irreversible loss of seed number. To start with, we provide an overview of the developmental and physiological basis of controlling seed setting in response to heat stress. It is shown that every single process of seed setting including male and female gametophyte development, fertilization, and early seed/fruit development is sensitive to heat stress, in particular male reproductive development in legume crops is especially susceptible. A series of physiochemical processes including heat shock proteins, antioxidants, metabolites, and hormones centered with sugar starvation are proposed to play a key role in regulating legume seed setting in response to heat stress. The exploration of the molecular mechanisms underlying reproductive heat tolerance is in its infancy. Medicago truncatula, with a small diploid genome, and well-established transformation system and molecular platforms, has become a valuable model for testing gene function that can be applied to advance the physiological and molecular understanding of legume reproductive heat tolerance.

Correction: Functional implications of hexameric assembly of RraA proteins from Vibrio vulnificus

[This corrects the article DOI: 10.1371/journal.pone.0190064.].