PTMs in Conversation: Activity and Function of Deubiquitinating Enzymes Regulated via Post-Translational Modifications

Deubiquitinating enzymes (DUBs) constitute a diverse protein family and their impact on numerous biological and pathological processes has now been widely appreciated. Many DUB functions have to be tightly controlled within the cell, and this can be achieved in several ways, such as substrate-induced conformational changes, binding to adaptor proteins, proteolytic cleavage, and post-translational modifications (PTMs). This review is focused on the role of PTMs including monoubiquitination, sumoylation, acetylation, and phosphorylation as characterized and putative regulative factors of DUB function. Although this aspect of DUB functionality has not been yet thoroughly studied, PTMs represent a versatile and reversible method of controlling the role of DUBs in biological processes. In several cases PTMs might constitute a feedback mechanism insuring proper functioning of the ubiquitin proteasome system and other DUB-related pathways

Psychometric evaluation of the Dundee Ready Educational Environment Measure: Swedish version.

Background: The Dundee Ready Educational Environment Measure (DREEM) has been used in various studies to evaluate the educational environment. However, psychometric evaluations of the instrument seem sparse, for all known versions of the instrument. Aim: The aim was to psychometrically evaluate the Swedish version of the DREEM instrument. Method: A total of 503 students (undergraduate medicine), aged 19-46 years, in semesters 2, 6 and 10 were included in the study. Validity was evaluated through analysis of construct validity and reliability. Results: The instrument had in general both acceptable validity and reliability. Due to a rather poor model fit in the confirmatory factor analysis, an explorative factor analysis was also employed which suggested a new five-factor solution for the instrument. Conclusions: The Swedish version of the DREEM instrument is shown to be valid and reliable, except for the factor structure. The new five-factor solution found in this study is not proven to be a superior measurement model compared with the original, but could be seen as an alternative model to the original, where the strong and weak areas are somewhat more easily identified

Design and implementation of three incoherent feed-forward motif based biological concentration sensors

Synthetic biology is a useful tool to investigate the dynamics of small biological networks and to assess our capacity to predict their behavior from computational models. In this work we report the construction of three different synthetic networks in Escherichia coli based upon the incoherent feed-forward loop architecture. The steady state behavior of the networks was investigated experimentally and computationally under different mutational regimes in a population based assay. Our data shows that the three incoherent feed-forward networks, using three different macromolecular inhibitory elements, reproduce the behavior predicted from our computational model. We also demonstrate that specific biological motifs can be designed to generate similar behavior using different components. In addition we show how it is possible to tune the behavior of the networks in a predicable manner by applying suitable mutations to the inhibitory elements