Catálogo de publicaciones - revistas

<jats:title>Engineering a toxin</jats:title> <jats:p> Developing drugs that target a specific subtype in a G protein–coupled receptor (GPCR) family is a major challenge. Maeda <jats:italic>et al.</jats:italic> examined the basis of specificity of a snake venom toxin binding to muscarinic acetylcholine receptors (MAChRs), which mediate many functions of the central and parasympathetic nervous systems. They determined a structure that shows why the mamba venom toxin MT7 is specific for one receptor, M <jats:sub>1</jats:sub> AChR, and also explains how it inhibits downstream signaling. Based on this structure, they engineered MT7 to be selective for another receptor, M <jats:sub>2</jats:sub> AChR, instead of M <jats:sub>1</jats:sub> ChR. The toxin may present a promising scaffold for developing specific GPCR modulators. </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" issue="6500" page="161" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aax2517">161</jats:related-article> </jats:p>

<jats:title>Plasma transfers exercise benefit in mice</jats:title> <jats:p> Exercise has a broad range of beneficial healthful effects. Horowitz <jats:italic>et al.</jats:italic> tested whether the beneficial effects of exercise on neurogenesis in the brain and improved cognition in aged mice could be transferred in plasma (blood without its cellular components) from one mouse to another (see the Perspective by Ansere and Freeman). Indeed, aged mice that received plasma from young or old mice that had exercised showed beneficial effects in their brains without hitting the treadmill. The authors identified glycosylphosphatidylinositol-specific phospholipase D1 as a factor in plasma that might, in part, mediate this favorable effect. </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" issue="6500" page="167" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aaw2622">167</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6500" page="144" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abc8830">144</jats:related-article> </jats:p>

<jats:title>Strongly coupled at distance</jats:title> <jats:p> The development of hybrid quantum systems provides a flexibility that allows for various components to be coupled together, thereby expanding the opportunity to build quantum sensors and devices that can be designed for specific purposes. Key to doing so is being able to strongly couple the different components. Most developments to date have relied on the components being in close proximity, which can hamper design flexibility. Karg <jats:italic>et al.</jats:italic> used a laser to induce strong coupling between a cloud of atoms and an optomechanical membrane. With the components separated by 1 meter, this approach demonstrates a methodology of coupling quantum systems and easing up restrictions on spatial proximity. </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" issue="6500" page="174" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abb0328">174</jats:related-article> </jats:p>

<jats:title>A very high Chern number</jats:title> <jats:p> Topologically nontrivial electronic structure can often be characterized by the Chern number, the value of which is related to the magnitude of some of the exotic effects predicted to occur in such systems. Many topological phases discovered so far have a Chern number of 1 or 2, but higher values are also theoretically possible. Schröter <jats:italic>et al.</jats:italic> predicted that the chiral material palladium gallium (PdGa) would have a Chern number of 4, and they confirmed that prediction using photoemission experiments. Interestingly, the sign of the Chern number was opposite for the two enantiomers of PdGa. </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" issue="6500" page="179" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aaz3480">179</jats:related-article> </jats:p>

<jats:title>A metallic route for protons</jats:title> <jats:p> The operating temperatures of solid oxide fuel cells are usually much higher than needed to drive the uncatalyzed electrochemical reaction to transport oxygen anions or protons through ceramic electrolytes. Wu <jats:italic>et al.</jats:italic> report that the interface between two semiconductors, Na <jats:sub>x</jats:sub> CoO <jats:sub>2</jats:sub> and CeO <jats:sub>2</jats:sub> , forms a metallic state that enables proton transport at temperatures below 600°C (see the Perspective by Ni and Shao). The authors constructed a hydrogen fuel cell with this material that delivered 1 watt per centimeter. </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" issue="6500" page="184" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aaz9139">184</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6500" page="138" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abc9136">138</jats:related-article> </jats:p>

<jats:title>Knowing their way around</jats:title> <jats:p> The presence of a cognitive map is essential to our ability to navigate through areas we know because it facilitates the use of spatial knowledge to derive new routes. Whether such maps exist in nonhuman animals has been debated, largely because of the difficulty of demonstrating qualifying components of the map outside of a laboratory. In two studies on Egyptian fruit bats, Harten <jats:italic>et al.</jats:italic> and Toledo <jats:italic>et al.</jats:italic> together show that this species's navigational strategies meet the requirements for the use of a cognitive map of their environment, confirming that this skill occurs outside of humans (see the Perspective by Fenton). </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" issue="6500" page="194" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aay3354">194</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6500" page="188" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aax6904">188</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6500" page="142" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abd1213">142</jats:related-article> </jats:p>

<jats:title>Knowing their way around</jats:title> <jats:p> The presence of a cognitive map is essential to our ability to navigate through areas we know because it facilitates the use of spatial knowledge to derive new routes. Whether such maps exist in nonhuman animals has been debated, largely because of the difficulty of demonstrating qualifying components of the map outside of a laboratory. In two studies on Egyptian fruit bats, Harten <jats:italic>et al.</jats:italic> and Toledo <jats:italic>et al.</jats:italic> together show that this species's navigational strategies meet the requirements for the use of a cognitive map of their environment, confirming that this skill occurs outside of humans (see the Perspective by Fenton). </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" issue="6500" page="194" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aay3354">194</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6500" page="188" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aax6904">188</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6500" page="142" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abd1213">142</jats:related-article> </jats:p>

<jats:title>Food for thought</jats:title> <jats:p> Phytoplankton abundances in the Arctic Ocean have been increasing over recent decades as the region has warmed and sea ice has disappeared. The presumptive causes of this increase were expanding open water area and a longer growing season—at least until now. Lewis <jats:italic>et al.</jats:italic> show that although these factors may have driven the productivity trends before, over the past decade, phytoplankton primary production rose by more than half because of increased phytoplankton concentrations (see the Perspective by Babin). This finding means that there has been an influx of new nutrients into the region, suggesting that the Arctic Ocean could become more productive and export additional carbon in the future. </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" issue="6500" page="198" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aay8380">198</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6500" page="137" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abd1231">137</jats:related-article> </jats:p>

<jats:title>An inherited disorder makes WAVEs</jats:title> <jats:p> The WAVE regulatory complex (WRC) is a multiunit complex that regulates actin cytoskeleton formation. Although other actin-regulatory proteins modulate human immune responses, the precise role for the WRC has not yet been established. Cook <jats:italic>et al.</jats:italic> studied five patients from four unrelated families who harbor missense variants of the gene encoding the WRC component HEM1. These patients presented with recurrent infections and poor antibody responses, along with enhanced allergic and autoimmune disorders. HEM1 was found to be required for the regulation of cortical actin and granule release in T cells and also interacted with a key metabolic signaling complex contributing to the disease phenotype. By linking these interactions to immune function, this work suggests potential targets for future immunotherapies. </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" issue="6500" page="202" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aay5663">202</jats:related-article> </jats:p>