201 research outputs found
The genetic switch for the regulatory pathway of Lactobacillus plantarum phage φg1e
Faculty of Engineering, Kanazawa UniversityMolecular Biology Group, Faculty of Engineering, Toyama UniversityMolecular Biology Group, Faculty of Engineering, Toyama UniversityDepartment of Applied physics and Chemistry, Fukui University of Technology, GakuenMolecular Biology Group, Faculty of Engineering, Toyama Universit
The FASTK family proteins fine-tune mitochondrial RNA processing.
Funder: The Cancer Council of Western AustraliaFunder: UWA Postgraduate ScholarshipsTranscription of the human mitochondrial genome and correct processing of the two long polycistronic transcripts are crucial for oxidative phosphorylation. According to the tRNA punctuation model, nucleolytic processing of these large precursor transcripts occurs mainly through the excision of the tRNAs that flank most rRNAs and mRNAs. However, some mRNAs are not punctuated by tRNAs, and it remains largely unknown how these non-canonical junctions are resolved. The FASTK family proteins are emerging as key players in non-canonical RNA processing. Here, we have generated human cell lines carrying single or combined knockouts of several FASTK family members to investigate their roles in non-canonical RNA processing. The most striking phenotypes were obtained with loss of FASTKD4 and FASTKD5 and with their combined double knockout. Comprehensive mitochondrial transcriptome analyses of these cell lines revealed a defect in processing at several canonical and non-canonical RNA junctions, accompanied by an increase in specific antisense transcripts. Loss of FASTKD5 led to the most severe phenotype with marked defects in mitochondrial translation of key components of the electron transport chain complexes and in oxidative phosphorylation. We reveal that the FASTK protein family members are crucial regulators of non-canonical junction and non-coding mitochondrial RNA processing
A cross-sectional association of obesity with coronary calcium among Japanese, Koreans, Japanese-Americans, and US-Whites
[Aims] Conflicting evidence exists regarding whether obesity is independently associated with coronary artery calcium (CAC), a measure of coronary atherosclerosis. We examined an independent association of obesity with prevalent CAC among samples of multi-ethnic groups whose background populations have varying levels of obesity and coronary heart disease (CHD). [Methods and results] We analysed a population-based sample of 1212 men, aged 40–49 years free of clinical cardiovascular disease recruited in 2002–06; 310 Japanese in Japan (JJ), 294 Koreans in South Korea (KN), 300 Japanese Americans (JA), and 308 Whites in the USA (UW). We defined prevalent CAC as an Agatston score of ≥10. Prevalent CAC was calculated by tertile of the body mass index (BMI) in each ethnic group and was plotted against the corresponding median of tertile BMI. Additionally, logistic regression was conducted to examine whether an association of the BMI was independent of conventional risk factors. The median BMI and crude prevalence of CAC for JJ, KN, JA, and UW were 23.4, 24.4, 27.4, and 27.1 (kg/m2); 12, 11, 32, and 26 (%), respectively. Despite the absolute difference in levels of BMI and CAC across groups, higher BMI was generally associated with higher prevalent CAC in each group. After adjusting for age, smoking, alcohol, hypertension, lipids, and diabetes mellitus, the BMI was positively and independently associated with prevalent CAC in JJ, KN, UW, but not in JA. [Conclusion] In this multi-ethnic study, obesity was independently associated with subclinical stage of coronary atherosclerosis among men aged 40–49 years regardless of the BMI level
Long-chain n-3 polyunsaturated fatty acids intake and cardiovascular disease mortality risk in Japanese: a 24-year follow-up of NIPPON DATA80
Background:Dietary intake of long-chain n-3 PUFA (LCn3FA) among Japanese is generally higher than that in Western populations. However, little is known whether an inverse association of LCn3FA with cardiovascular disease (CVD) risk exists in a population with higher LCn3FA intake.Objective:To investigate the association between LCn3FA intake and the long-term risk of CVDs in a Japanese general population.Methods:We followed-up a total of 9190 individuals (56.2% women, mean age 50.0 years) randomly selected from 300 areas across Japan and free from CVDs at baseline. Dietary LCn3FA intake was estimated using household weighed food records. Cox models were used to calculate multivariate-adjusted hazard ratios (HR) and confidence intervals (CI) according to sex specific quartiles of LCn3FA intake.Results:During 24-year follow-up (192,897 person-years), 879 cardiovascular deaths were observed. The median daily intake of LCn3FA was 0.37% kcal (0.86 g/day). Adjusted HR for CVD mortality was lower in the highest quartile of LCn3FA intake (HR 0.80; 95% CI 0.66-0.96) compared with the lowest quartile, and the trend was statistically significant (P = 0.038). The similar but statistically non-significant trends were observed for coronary heart disease death and stroke death. In analyses by age groups, the inverse associations of LCn3FA intake with the risk of total CVD death and stroke death were significant in younger individuals (30-59 years at baseline).Conclusion:LCn3FA intake was inversely and independently associated the long-term risk of total CVD mortality in a representative sample of Japanese with high LCn3FA intake
Comparing tropical forest tree size distributions with the predictions of metabolic ecology and equilibrium models
Tropical forests vary substantially in the densities of trees of different sizes and thus in above-ground biomass and carbon stores. However, these tree size distributions show fundamental similarities suggestive of underlying general principles. The theory of metabolic ecology predicts that tree abundances will scale as the -2 power of diameter. Demographic equilibrium theory explains tree abundances in terms of the scaling of growth and mortality. We use demographic equilibrium theory to derive analytic predictions for tree size distributions corresponding to different growth and mortality functions. We test both sets of predictions using data from 14 large-scale tropical forest plots encompassing censuses of 473 ha and \u3e 2 million trees. The data are uniformly inconsistent with the predictions of metabolic ecology. In most forests, size distributions are much closer to the predictions of demographic equilibrium, and thus, intersite variation in size distributions is explained partly by intersite variation in growth and mortality. © 2006 Blackwell Publishing Ltd/CNRS
Testing metabolic ecology theory for allometric scaling of tree size, growth and mortality in tropical forests
The theory of metabolic ecology predicts specific relationships among tree stem diameter, biomass, height, growth and
mortality. As demographic rates are important to estimates of carbon fluxes in forests, this theory might offer important insights into
the global carbon budget, and deserves careful assessment. We assembled data from 10 old-growth tropical forests encompassing
censuses of 367 ha and > 1.7 million trees to test the theory's predictions. We also developed a set of alternative predictions
that retained some assumptions of metabolic ecology while also considering how availability of a key limiting resource, light, changes
with tree size. Our results show that there are no universal scaling relationships of growth or mortality with size among trees in tropical
forests. Observed patterns were consistent with our alternative model in the one site where we had the data necessary to evaluate it,
and were inconsistent with the predictions of metabolic ecology in all forests
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