Rapamycin-Induced Abundance Changes in the Proteome of Budding Yeast

The target of rapamycin (TOR) signaling pathway conserved from yeast to human plays critical roles in regulation of eukaryotic cell growth. It has been shown that TOR pathway is involved in several cellular processes, including ribosome biogenesis, nutrient response, autophagy and aging. However, due to the functional diversity of TOR pathway, we do not know yet some key effectors of the pathway. To find unknown effectors of TOR signaling pathway, we took advantage of a green fluorescent protein (GFP)-tagged collection of budding yeast Saccharomyces cerevisiae . We analyzed protein abundance changes by measuring the GFP fluorescence intensity of 4156 GFP-tagged yeast strains under inhibition of TOR pathway. Our proteomic analysis argues that 83 proteins are decreased whereas 32 proteins are increased by treatment of rapamycin, a specific inhibitor of TOR complex 1 (TORC1). We found that, among the 115 proteins that show significant changes in protein abundance under rapamycin treatment, 37 proteins also show expression changes in the mRNA levels by more than 2-fold under the same condition. We suggest that the 115 proteins indentified in this study may be directly or indirectly involved in TOR signaling and can serve as candidates for further investigation of the effectors of TOR pathway.

The Comparison of Job Stress Factors, Psychosocial Stress and Their Association between Research and Manufacturing Workers in an Automobile Research and Developing Company / 대한산업의학회지

OBJECTIVES: This study was conducted to investigate the job stress factors, psychosocial stress and their associations in workers engaged in the research and development of vehicles, and according to job role. METHODS: We recruited 4,066 subjects from workers at a research and development center of an automobile company. A total of 2,764 workers answered the questionnaire about socio-demographic factors, health behaviors, work-related factors, subjective labor intensity, KOSS, and SF-PWI. The final analysis included 2,282 male manufacturing and research workers. Univariate analyses and multiple logistic analyses were conducted on the complete questionnaire data to compare the job stress factors, psychosocial stress and their associations between research and manufacturing workers. RESULTS: The adjusted Odds ratios comparing the high risk group to the low risk group regarding PWI group were 2.23(95%CI=1.63-3.04) in "Lack of rewards", 1.64(95%CI=1.20-2.24) in "Interpersonal conflict", 1.59(95%CI=1.15- 2.20) in "Organizational injustice", 1.58(95%CI=1.17-2.14) in "Occupational climate" and 1.43(95%CI=1.05-1.94) in "Job insecurity" among research workers, and 2.46(95%CI=1.59 -3.80) in "Lack of rewards" and 1.94(95%CI=1.17-3.22) in "Organizational injustice" among manufacturing workers. CONCLUSIONS: There are differences in job stress factors between research and manufacturing workers. Further studies and discussions based on quantitative methodology for seeking more fundamental causes of these differences are required to establish job stress intervention plans and policies.