Biennial Report 2005-2007 - Saha Institute of Nuclear Physics

218 Biennial Report 2005-07We have raised the polyclonal antisera against the bacterially expressed less conserved C-terminalportion of MRJ. Western blot analyses with the antiserum of the protein extract from synchronizedHeLa cells at different phases of the cell cycle have shown that the protein is overexpressed inmitosis phase. Immuno-fluoroscence with the same antiserum on HeLa cells has shown that MRJprotein is localized in the nuclear periphery and moving to nucleus at late G2-phase. Also we haveseen microscopically that MRJ is associated with nuclear cytoskeleton structure in dividing cellsduring M-phase. This phenomenon is further established in our biochemical analysis of fractionatedchromatin and non-chromatin protein from Hela cells. So it will be interesting to study the functionof MRJ in cell cycle and stress responsive pathway that can modify cell cycle.Sanjib Dey, Partha SahaC&MB6.1.6 Toxicology & Related Studies6.1.6.1 SOS induction by Heat ShockIn continuation of the study of SOS induction in Salmonella typhimurium cells by heat shock, ithas been revealed further that this effect is observable only by the synergistic action of heat shockand mechanical shearing in a water bath at 50 C. The effects of the individual agents and also incombination are being studied to arrive at some significant and meaningful conclusion.Mita Ghosh, A Pal, AK PalBP6.1.6.2 Role of Turmeric extracts in bacterial system:We have been working with turmeric extracts in bacterial assay system for quite a period of time,in order to explore its altogether unknown role/s, if any. We have come across another bioactivecomponent of turmeric over and above the already reported one viz. Curcumin. We are investigatingthe effects of the different bioactive components of turmeric (having altogether different properties)vis-A-vis the extract in totality, in bacterial assay systems.A Pal, Mita Ghosh, AK PalBP6.1.6.3 Environmental impacts on nitrogen fixing bacteriaThe soil bacteria Rhizobia are the most promising and agriculturally important group for biologicalnitrogen fixation.Crop producers often supplement chemical fertilizers for better growth and vigourof crop of choice.Indiscriminate use of fertilizers lead to accumulation of phosphates, nitrates andpotassium in the soil. These over application of fertilizers may be harmful to various soil inhabitants.Wehave already established that different nitrogenous fertilizers e.g., urea, ammonium sulfateand sodium nitrate in low to high doses have detrimental effect on Rhizobium sp. cells in liquidculture medium as revealed by microbiological and ultrastructural studies. Potassium based fertilizerse.g., potassium chloride and potassium sulphate also showed interesting results as revealed