The role of Schizosaccharomyces pombe SUMO ligases in genome stability

SUMOylation is a post-translational modification that affects a large number of proteins, many of which are nuclear. While the role of SUMOylation is beginning to be elucidated, it is clear that understanding the mechanisms that regulate the process is likely to be important. Control of the levels of SUMOylation is brought about through a balance of conjugating and deconjugating activities, i.e. of SUMO (small ubiquitin-related modifier) conjugators and ligases versus SUMO proteases. Although conjugation of SUMO to proteins can occur in the absence of a SUMO ligase, it is apparent that SUMO ligases facilitate the SUMOylation of specific subsets of proteins. Two SUMO ligases in Schizosaccharomyces pombe, Pli1 and Nse2, have been identified, both of which have roles in genome stability. We report here on a comparison between the properties of the two proteins and discuss potential roles for the proteins

Prediction of pH Change in Processed Acidified Turnips

The acetic acid uptake by turnips was studied during an acidification process in containers. The process was successfully described by a Fickian diffusion, using a correlation for the buffer effect. Diffusion coefficients (0.629 to 3.99 × 10-9 m2/sec) and partition coefficients (0.8 to 1.1) were obtained by optimization of the fit between experimental and theoretical values, using the simplex method. The partition coefficient did not show an evident dependence on temperature, while diffusivity followed an Arrhenius type behavior. The relationship between acid concentration and pH was described using a cubic model with parameters independent of temperature. Results showed that the combination of these models describing the acid diffusion into the food and the buffering effects of the food allowed accurate prediction of pH evolution in the acidification process

Low plasma volume coincides with sympathetic hyperactivity and reduced baroreflex sensitivity in formerly preeclamptic patients.

Contains fulltext : 50660.pdf (publisher's version ) (Open Access)BACKGROUND: Preeclampsia is associated with enhanced sympathetic activity as well as subnormal plasma volume. Meanwhile, in over 50% of these complicated pregnancies, the subnormal plasma volume has been found to persist for a prolonged period after pregnancy. The objective of this study is to test the hypothesis that in normotensive formerly-preeclamptic women, persistence of a subnormal plasma volume coincides with enhanced sympathetic activity and with it, an altered autonomic control of blood pressure. METHODS: Forty-eight formerly-preeclamptic women participated in this study. After measurement of their plasma volume by iodine 125-albumin indicator dilution, they were subdivided into a group with a normal plasma volume (plasma volume > 48 ml/kg lean body mass) and a group with a subnormal plasma volume (< or = 48 ml/kg lean body mass). We performed spectral analysis on their beat-to-beat blood pressure and heart rate recordings and compared both groups using non-parametric tests. RESULTS: Formerly-preeclamptic women with a subnormal plasma volume had a higher sympathetic activity (P = .001) and a lower baroreflex sensitivity (P = .04) than their counterparts with a normal plasma volume. CONCLUSION: In normotensive formerly-preeclamptic women, a subnormal plasma volume coincides with a higher sympathetic activity in the blood pressure regulation and lower baroreflex sensitivity. Whether these alterations in the autonomic control mechanisms are a cause or effect of the subnormal plasma volume remains to be elucidated