In this week's Science, a team led by researchers at the University of Gottingen Medical Center describe a three-dimensional model of an average synapse in the rat brain, which displays roughly 300,000 proteins in atomic detail. The scientists removed isolated synaptic terminals from the brains of adult rats and observed the details of the membrane trafficking pathway by which neurotransmitter-releasing synaptic vesicles are destroyed and rebuilt. Using a combination of Western blot and mass spectrometry, they determined the number of proteins involved and used electron microscopy to determine the positions of organelles. Super-resolution fluorescence microscopy was used to localize the proteins.
Also in Science, University of Wutzburg researcher Jörg Vogel discusses the role of argonaute proteins — the key effectors of virtually all eukaryotic small RNA-mediated gene silencing — that exist in bacteria. He highlights recent data suggesting that these proteins target DNA in bacteria as part of a defense mechanism and discusses the potential for harnessing bacteria argonautes to enhance the effects of CRISPR/Cas 9 gene editing.