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Byline: R. Sitalakshmi, P. Saikumar, P. Jeyachandran, Manoharan, Thangavel, Jayakar. Thomas Background: Construction industry is the second largest employment giving industry in India with many semi-skilled or unskilled workers taking [...]

Ribosome biogenesis is an essential cellular process regulated by the metabolic state of a cell. We examined whether inositol pyrophosphates, energy-rich derivatives of inositol that act as metabolic messengers, play a role in ribosome synthesis in the budding yeast, Saccharomyces cerevisiae. Yeast strains lacking the inositol hexakisphosphate (IP6) kinase Kcs1, which is required for the synthesis of inositol pyrophosphates, display increased sensitivity to translation inhibitors and decreased protein synthesis. These phenotypes are reversed on expression of enzymatically active Kcs1, but not on expression of the inactive form. The kcs1 Δ yeast cells exhibit reduced levels of ribosome subunits, suggesting that they are defective in ribosome biogenesis. The rate of rRNA synthesis, the first step of ribosome biogenesis, is decreased in kcs1 Δ yeast strains, suggesting that RNA polymerase I (Pol I) activity may be reduced in these cells. We determined that the Pol I subunits, A190, A43 and A34.5, can accept a β-phosphate moiety from inositol pyrophosphates to undergo serine pyrophosphorylation. Although there is impaired rRNA synthesis in kcs1 β yeast cells, we did not find any defect in recruitment of Pol I on rDNA, but observed that the rate of transcription elongation was compromised. Taken together, our findings highlight inositol pyrophosphates as novel regulators of rRNA transcription. [ABSTRACT FROM AUTHOR]

Background: Old age is associated with weakness of skeletal muscles and decrease in muscle functions. Usually in old-age, people undergo wasting of muscles, so they are more prone for fall and fracture. It has been stated that stress and cognition has an impact on muscle functions. This study was intended to demonstrate the effect of stress in muscle function in geriatrics. Methods: This was a cross sectional study done at a charitable home in Chennai sub urban. The geriatric males and females in the old age home were included in this study. Sixty-four subjects were included and the persons with previous history of musculo skeletal and neurological disorders were excluded. Anthropometric parameters were recorded Maximum Voluntary Contraction (MVC) and Endurance Time (ET) were measured by hand grip dynamometer. Perceived stress score was measured by perceived stress scale questionnaire. Muscle function parameters and stress score was compared. Results: Sixty-four subjects were included in this study and it was found out that there is a negative correlation between MVC & stress which was statistically significant. (r = -0.0675, P = 0.000). Age with MVC & ET showed a mild negative correlation but it was not significant. Conclusion: Hormones released during stress have a negative metabolic effect in skeletal muscle. Stress can induce earlier decline in muscle strength which will eventually lead to fall and fracture. Therefore, stress should be viewed as an independent risk factor for disability and other co morbid conditions. [ABSTRACT FROM AUTHOR]