Complex, Varied and Evolving Manifestations of Food Agency in Daily Life Among Diabetes Prevention Program Participants in Baltimore, Maryland.

OBJECTIVE: To characterize food agency (one's capacity to procure and prepare food in particular contexts) among Diabetes Prevention Program (DPP) participants and gather perspectives about experiences with DPP. DESIGN: Photograph-elicitation in-depth interviews and survey measures. SETTING: Baltimore, Maryland (June-August 2021). PARTICIPANTS: Black women (n = 13) who participated in DPP. PHENOMENON OF INTEREST: Food agency and strategies used to procure and prepare food and the influence of DPP on daily food behaviors. Surveys measured food agency using the Cooking and Food Provisioning Action Scale and cooking behaviors. ANALYSIS: Thematic analysis of qualitative in-depth interviews and descriptive statistics for quantitative measures. RESULTS: As quantitative and qualitative data revealed, participants were frequent and confident cooks with high food agency. Participants viewed cooking as a key strategy for healthy eating and desired more hands-on cooking instruction within DPP to develop new healthy cooking skills. The primary barriers identified were related to lack of time or energy. Food procurement and preparation practices shifted over time, and DPP was a key influence on current behaviors. CONCLUSIONS AND IMPLICATIONS: Food agency is complex and manifests heterogeneously in daily life. A life course, contextual, and food agency-based approach could be considered for future diabetes prevention interventions.

The respiratory syncytial virus matrix protein possesses a Crm1-mediated nuclear export mechanism.

The respiratory syncytial virus (RSV) matrix (M) protein is localized in the nucleus of infected cells early in infection but is mostly cytoplasmic late in infection. We have previously shown that M localizes in the nucleus through the action of the importin beta1 nuclear import receptor. Here, we establish for the first time that M's ability to shuttle to the cytoplasm is due to the action of the nuclear export receptor Crm1, as shown in infected cells, and in cells transfected to express green fluorescent protein (GFP)-M fusion proteins. Specific inhibition of Crm1-mediated nuclear export by leptomycin B increased M nuclear accumulation. Analysis of truncated and point-mutated M derivatives indicated that Crm1-dependent nuclear export of M is attributable to a nuclear export signal (NES) within residues 194 to 206. Importantly, inhibition of M nuclear export resulted in reduced virus production, and a recombinant RSV carrying a mutated NES could not be rescued by reverse genetics. That this is likely to be due to the inability of a nuclear export deficient M to localize to regions of virus assembly is indicated by the fact that a nuclear-export-deficient GFP-M fails to localize to regions of virus assembly when expressed in cells infected with wild-type RSV. Together, our data suggest that Crm1-dependent nuclear export of M is central to RSV infection, representing the first report of such a mechanism for a paramyxovirus M protein and with important implications for related paramyxoviruses.

Central role of the respiratory syncytial virus matrix protein in infection.

Respiratory syncytial virus is the major respiratory pathogen of infants and children worldwide, with no effective treatment or vaccine available. Steady progress has been made in understanding the respiratory syncytial virus life cycle and the consequences of infection, but many areas of respiratory syncytial virus biology remain poorly understood, including the role of subcellular localisation of respiratory syncytial virus gene products such as the matrix protein in the infected host cell. The matrix protein plays a central role in viral assembly and, intriguingly, has been observed to traffic into and out of the nucleus at specific times during the respiratory syncytial virus infectious cycle. Further, the matrix protein has been shown to be able to inhibit transcription, which may be a key to respiratory syncytial virus pathogenesis. This review will focus on the role of the matrix protein in respiratory syncytial virus infection and what is known of its nucleocytoplasmic trafficking, the understanding of which may lead to new therapeutic approaches to combat respiratory syncytial virus, and/or vaccine development.

Nuclear import of the respiratory syncytial virus matrix protein is mediated by importin beta1 independent of importin alpha.

The matrix (M) protein of respiratory syncytial virus (RSV) plays an important role in virus assembly through specific interactions with RSV nucleocapsids and envelope glycoproteins in the cytoplasm as well as with the host cell membrane. We have previously shown that M localizes to the nucleus of infected cells at an early stage in the RSV infection cycle, where it may be instrumental in inhibiting host cell processes. The present study uses transient expression of M as well as a truncated green fluorescent protein (GFP) fusion derivative to show for the first time that M is able to localize in the nucleus in the absence of other RSV gene products, through the action of amino acids 110-183, encompassing the nucleic acid binding regions of the protein, that are sufficient to target GFP to the nucleus. Using native PAGE, ELISA-based binding assays, a novel Alphascreen assay, and an in vitro nuclear transport assay, we show that M is recognized directly by the importin beta1 nuclear import receptor, which mediates its nuclear import in concert with the guanine nucleotide-binding protein Ran. Retention of M in the nucleus through binding to nuclear components, probably mediated by the putative zinc finger domain of M, also contributes to M nuclear accumulation. This is the first report of the importin binding and nuclear import properties of a gene product from a negative sense RNA virus, with implications for the function of RSV M and possibly other viral M proteins in the nucleus of infected cells.