Direct Observation of Dimerization between Different CREB1 Isoforms in a Living Cell

Cyclic AMP-responsive element binding protein 1 (CREB1) plays multiple functions as a transcription factor in gene regulation. CREB1 proteins are also known to be expressed in several spliced isoforms that act as transcriptional activators or repressors. The activator isoforms, possessing the functional domains for kinase induction and for interaction with other transcriptional regulators, act as transcriptional activators. On the other hand, some isoforms, lacking those functional domains, are reported to be repressors that make heterodimers with activator isoforms. The complex and ingenious function for CREB1 arises in part from the variation in their spliced isoforms, which allows them to interact with each other. To date, however, the dimerization between the activator and repressor isoforms has not yet been proved directly in living cells. In this study, we applied fluorescence cross-correlation spectroscopy (FCCS) to demonstrate direct observation of dimerization between CREB1 activator and repressor. The FCCS is a well established spectroscopic method to determine the interaction between the different fluorescent molecules in the aqueous condition. Using differently labeled CREB1 isoforms, we successfully observed the interaction of CREB1 activator and repressor via dimerization in the nuclei of cultured cells. As a result, we confirmed the formation of heterodimer between CREB1 activator and repressor isoforms in living cells

Green Urbanism and its Application to Singapore

Green urbanism has been applied to cities but not in Asia. Seven characteristics of green urbanism are outlined and then applied to Singapore. The Renewable City is not yet a concept for Singapore. The Carbon Neutral City is being developed for an island Palau Ubin and by some firms but not to significant sectors or parts of urban Singapore. The Distributed City is being developed around Singapore’s polycentric model but needs specific infrastructure plans similar to ones developed by Singapore for Tianjin Eco-City. The Biophillic City is being developed as a world first through its Skyrise Greenery initiative and urban landscaping. The Eco-Efficient City is also being demonstrated through Singapore closing the loop on their water and solid waste systems. The Place Based City is very evident in all its 22 sub centres. And the Sustainable Transport City is an Asian leader in integrated transport planning though there are signs of this becoming harder to achieve

A microplate technique to simultaneously assay calcium accumulation in endoplasmic reticulum and SERCA release of inorganic phosphate

Traditional analyses of calcium homeostasis have separately quantified either calcium accumulation or release mechanisms. To define the system as a whole, however, requires multiple experimental techniques to examine both accumulation and release. Here we describe a technique that couples the simultaneous quantification of radio-labeled calcium accumulation in endoplasmic reticulum (ER) microsomes with the release of inorganic phosphate (Pi) by the hydrolytic activity of sarco-endoplasmic reticulum calcium ATPase (SERCA) all in the convenience of a 96-well format

Salmonella enterica Serotype Gambia with CTX-M-3 and armA Resistance Markers: Nosocomial Infections with a Fatal Outcome▿

We report two cases of bacteremia caused by the Salmonella enterica serotype Gambia in our children's hospital, with one fatal outcome. The isolates showed indistinguishable genotypes and infrequent resistance markers: CTX-M-3 extended-spectrum β-lactamase and armA methyltransferase. This is the first report of S. Gambia exhibiting CTX-M-3 and armA markers involved in serious infections