Two papers in Science this week focus on the mechanosensitive channel of small conductance (MscS) in E. coli, important for regulating osmotic pressure through rapid ion flux. In one, Scottish researchers determined the 3.45 angstrom-resolution structure of the channel in an open conformation. In other work, scientists used electron paramagnetic resonance spectroscopy and computational analyses to determine the structural changes that occur when the channel opens and closes. Says a related Perspective, "Progress in membrane protein structural biology may appear glacial but is speeding up, and the focus is increasingly shifting to the structural definition of multiple conformational states.
Research out of the Harvard Stem Cell Institute has generated patient-specific iPS cells from an 82-year-old woman with amyotrophic lateral sclerosis and then successfully made them differentiate into motor neurons, the cell type destroyed in ALS. A Perspective relates the findings to practical application, which is the "holy grail in neurodegenerative disorders," using a patient's own cells for transplantation without rejection.
At MIT, scientists have used bioinformatic analysis coupled with gene expression studies in Pseudomonas aeruginosa and Streptomyces coelicolor to find that the excreted redox-active pigments from these bacteria play a role not just in the oxidative stress reponse but in regulating the structure of the microbial community.