Catálogo de publicaciones - revistas

<jats:title>A complex channel comes into focus</jats:title> <jats:p> Voltage-gated calcium (Cav) channels are activated in response to membrane potential to initiate calcium-mediated signaling pathways and are associated with diseases such as cardiac arrhythmia and epilepsy. Cav1.1 couples changes in membrane potential to cardiac muscle contraction. It comprises a core subunit and three auxiliary subunits. Wu <jats:italic>et al.</jats:italic> isolated the Cav1.1 complex from rabbit skeletal muscle and determined its structure by single-particle electron cryomicroscopy using direct electron detection and advanced image processing. The detailed architecture of the pseudotetrameric eukaryotic Cav channel in complex with its auxiliary subunits provides an important framework for understanding the function and disease mechanisms of related channels. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" related-article-type="in-this-issue" xlink:href="10.1126/science.aad2395">10.1126/science.aad2395</jats:related-article> </jats:p>

<jats:title>A channel involved in pain perception</jats:title> <jats:p> Voltage-gated sodium (Nav) channels propagate electrical signals in muscle cells and neurons. In humans, Nav1.7 plays a key role in pain perception. It is challenging to target a particular Nav isoform; however, arylsulfonamide antagonists selective for Nav1.7 have been reported recently. Ahuja <jats:italic>et al.</jats:italic> characterized the binding of these small molecules to human Nav channels. To further investigate the mechanism, they engineered a bacterial Nav channel to contain features of the Nav1.7 voltage-sensing domain that is targeted by the antagonist and determined the crystal structure of the chimera bound to an inhibitor. The structure gives insight into the mechanism of voltage sensing and will enable the design of more-selective Nav channel antagonists. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" related-article-type="in-this-issue" xlink:href="10.1126/science.aac5464">10.1126/science.aac5464</jats:related-article> </jats:p>

<jats:title>Advances in seeing small things</jats:title> <jats:p>Electron microscopes, particularly those with aberration correction, can view materials at the subnanometer scale. Additional improvements make it possible to obtain images at lower electron doses, thus minimizing the damage to the sample. However, for a number of materials, particularly those of biological origin, samples need to be imaged in solution. Ross reviews recent advances that have made it possible to do liquid cell electron microscopy, which opens up the possibility of studying problems such as the changes inside a battery during operation, the growth of crystals from solution, or biological molecules in their native state.</jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" related-article-type="in-this-issue" xlink:href="10.1126/science.aaa9886">10.1126/science.aaa9886</jats:related-article> </jats:p>

<jats:p> A, T, G, C: the alphabet code for the nucleotides that are the building blocks of life. Minor, but consequential, changes in this DNA coding can change gene function. Researchers have long sought better ways to edit the genetic code in cultured cells and laboratory organisms to silence, activate, or change targeted genes to gain a better understanding of their roles. This, in turn, could open the door to beneficial applications, from ecological to agricultural to biomedical. Over the years, several editing methods have been developed, but they have suffered from a lack of specificity, difficulty in assembling the molecular constituents, or concerns about off-target effects. Recently, accomplishments in genome editing across biological disciplines have been so remarkable that the method known as clustered regularly interspaced short palindromic repeats—or CRISPR—is <jats:italic>Science</jats:italic> 's 2015 Breakthrough of the Year (see p. 1456). </jats:p>

<jats:p>A roundup of weekly science policy and related news.</jats:p>