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Riboregulators such as riboswitches and RNA thermometers provide simple, protein-independent tools to control gene expression at the post-transcriptional level. In bacteria, RNA thermometers regulate protein synthesis in response to temperature shifts. Thermometers outside of the bacterial world are rare, and in organellar genomes, no RNA thermometers have been identified to date. Here we report the discovery of an RNA thermometer in a chloroplast gene of the unicellular green alga Chlamydomonas reinhardtii. The thermometer, residing in the 5' untranslated region of the psaA messenger RNA forms a hairpin-type secondary structure that masks the Shine-Dalgarno sequence at 25°C. At 40°C, melting of the secondary structure increases accessibility of the Shine-Dalgarno sequence to initiating ribosomes, thus enhancing protein synthesis. By targeted nucleotide substitutions and transfer of the thermometer into Escherichia coli, we show that the secondary structure is necessary and sufficient to confer the thermometer properties. We also demonstrate that the thermometer provides a valuable tool for inducible transgene expression from the Chlamydomonas plastid genome, in that a simple temperature shift of the algal culture can greatly increase recombinant protein yields., (© The Author(s) 2023. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Numerous studies have indicated that ambient particulate matter is closely associated with increased risk of cardiovascular disease, yet the evidence for its association with renal disease remains underrecognized. We aimed to estimate the association between long-term exposure to fine particulate matter, defined as particulate matter with an aerodynamic diameter less than or equal to 2.5 μm (PM2.5), and mortality from renal failure (RF) among participants in the Elderly Health Service Cohort in Hong Kong, China, from 1998 to 2010. PM2.5 concentration at the residential address of each participant was estimated based on a satellite-based spatiotemporal model. We used Cox proportional hazards regression to estimate risks of overall RF and cause-specific mortality associated with PM2.5. After excluding 5,373 subjects without information on residential address or relevant covariates, we included 61,447 participants in data analyses. We identified 443 RF deaths during the 10 years of follow-up. For an interquartile-range increase in PM2.5 concentration (3.22 μg/m3), hazard ratios for RF mortality were 1.23 (95% confidence interval: 1.06, 1.43) among all cohort participants and 1.42 (95% confidence interval: 1.16, 1.74) among patients with chronic kidney disease. Long-term exposure to atmospheric PM2.5 might be an important risk factor for RF mortality in the elderly, especially among persons with existing renal diseases., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Protein secretion is an essential process in all eukaryotic cells and its mechanisms have been extensively studied. Proteins with an N-terminal leading sequence or transmembrane domain are delivered through the conventional protein secretion (CPS) pathway from the endoplasmic reticulum (ER) to the Golgi apparatus. This feature is conserved in yeast, animals, and plants. In contrast, the transport of leaderless secretory proteins (LSPs) from the cytosol to the cell exterior is accomplished via the unconventional protein secretion (UPS) pathway. So far, the CPS pathway has been well characterized in plants, with several recent studies providing new information about the regulatory mechanisms involved. On the other hand, studies on UPS pathways in plants remain descriptive, although a connection between UPS and the plant defense response is becoming more and more apparent. In this review, we present an update on CPS and UPS. With the emergence of new techniques, a more comprehensive understanding of protein secretion in plants can be expected in the future., (© The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The growth of pathogens potentially relevant to respiratory tract infection may be triggered by changes in ambient temperature. Few studies have examined the association between ambient temperature and pneumonia incidence, and no studies have focused on the susceptible elderly population. We aimed to examine the short-term association between ambient temperature and geriatric pneumonia and to assess the disease burden attributable to cold and hot temperatures in Hong Kong, China. Daily time-series data on emergency hospital admissions for geriatric pneumonia, mean temperature, relative humidity, and air pollution concentrations between January 2005 and December 2012 were collected. Distributed-lag nonlinear modeling integrated in quasi-Poisson regression was used to examine the exposure-lag-response relationship between temperature and pneumonia hospitalization. Measures of the risk attributable to nonoptimal temperature were calculated to summarize the disease burden. Subgroup analyses were conducted to examine the sex difference. We observed significant nonlinear and delayed associations of both cold and hot temperatures with pneumonia in the elderly, with cold temperatures having stronger effect estimates. Among the 10.7% of temperature-related pneumonia hospitalizations, 8.7% and 2.0% were attributed to cold and hot temperatures, respectively. Most of the temperature-related burden for pneumonia hospitalizations in Hong Kong was attributable to cold temperatures, and elderly men had greater susceptibility., (© The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Few studies have explored age and sex differences in the disease burden of influenza, although men and women probably differ in their susceptibility to influenza infections. In this study, quasi-Poisson regression models were applied to weekly age- and sex-specific hospitalization numbers of pneumonia and influenza cases in the Hong Kong SAR, People's Republic of China, from 2004 to 2010. Age and sex differences were assessed by age- and sex-specific rates of excess hospitalization for influenza A subtypes A(H1N1), A(H3N2), and A(H1N1)pdm09 and influenza B, respectively. We found that, in children younger than 18 years, boys had a higher excess hospitalization rate than girls, with the male-to-female ratio of excess rate (MFR) ranging from 1.1 to 2.4. MFRs of hospitalization associated with different types/subtypes were less than 1.0 for adults younger than 40 years except for A(H3N2) (MFR = 1.6), while all the MFRs were equal to or higher than 1.0 in adults aged 40 years or more except for A(H1N1)pdm09 in elderly persons aged 65 years or more (MFR = 0.9). No MFR was found to be statistically significant (P < 0.05) for hospitalizations associated with influenza type/subtype. There is some limited evidence on age and sex differences in hospitalization associated with influenza in the subtropical city of Hong Kong., (© The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The evolutionarily conserved RNA Polymerase II Rpb4/7 sub-complex has been thoroughly studied in yeast and impacts gene expression at multiple levels including transcription, mRNA processing and decay. In addition Rpb4/7 exerts differential effects on gene expression in yeast and Rpb4 is not obligatory for yeast (S. cerevisiae) survival. Specialised roles for human (hs) Rpb4/7 have not been extensively described and we have probed this question by depleting hsRpb4/7 in established human cell lines using RNA interference. We find that Rpb4/7 protein levels are inter-dependent and accordingly, the functional effects of depleting either protein are co-incident. hsRpb4/7 exhibits gene-specific effects and cells initially remain viable upon hsRpb4/7 depletion. However prolonged hsRpb4/7 depletion is cytotoxic in the range of cell lines tested. Protracted cell death occurs by an unknown mechanism and in some cases is accompanied by a pronounced elongated cell morphology. In conclusion we provide evidence for a gene-specific role of hsRpb4/7 in human cell viability.

Aberrant chromosomal fusion of the Ewing's sarcoma oncogene (EWS) to several different cellular partners produces the Ewing's family of oncoproteins (EWS-fusion-proteins, EFPs) and associated tumors (EFTs). EFPs are potent transcriptional activators, dependent on the N-terminal region of EWS (the EWS-activation-domain, EAD) and this function is thought to be central to EFT oncogenesis and maintenance. Thus EFPs are promising therapeutic targets, but detailed molecular studies will be pivotal for exploring this potential. Such studies have so far largely been restricted to intact mammalian cells while recent evidence has indicated that a mammalian cell-free transcription system may not support bona fide EAD function. Therefore, the lack of manipulatable assays for the EAD presents a significant barrier to progress. Using Xenopus laevis oocytes we describe a plasmid-based micro-injection assay that supports efficient, bona fide EAD transcriptional activity and hence provides a new vehicle for molecular dissection of the EAD.

Background: The impact of influenza on mortality in countries in subtropical and tropical regions is poorly quantified. Estimation of influenza-related illness in warm-climate regions is more difficult, because the seasonality of virus circulation is less well-defined. Partly as a result of these factors, influenza vaccine is grossly underutilized in the tropics, even for individuals >or=65 years of age., Methods: Weekly numbers of deaths were modeled by Poisson regression, and excess deaths attributable to influenza in Hong Kong were estimated for 1996-1999. Comparison of weekly mortality during periods of influenza predominance and periods of low influenza activity was used to derive an alternative estimate of influenza-associated mortality., Results: Estimates derived from the Poisson model indicated that influenza resulted in 7.3 deaths per 100,000 population per year (95% confidence interval [CI], 3.1-11.4) from cardiorespiratory disease among individuals aged 40-65 years and 102.0 deaths per 100,000 per population per year (95% CI, 61.2-142.7) among individuals aged >or=65 years. Although respiratory diseases accounted for the majority of influenza-related deaths, influenza also contributed to 13.8% (95% CI, 4.8%- 22.7%) and 5.3% (95% CI, 1.2%-9.3%) of deaths related to ischemic heart disease., Conclusion: Influenza is associated with deaths due to ischemic heart disease as well from respiratory diseases. Overall influenza-associated mortality in a region with a warm climate, such as Hong Kong, is comparable with that documented in temperate regions. The need for influenza vaccination in tropical regions needs to be reassessed.