Catálogo de publicaciones - revistas

<jats:title>Dynamic activation of a GPCR</jats:title> <jats:p> G protein–coupled receptors (GPCRs) coordinate a complex information flow between the outside and inside of a cell. An increasing number of GPCR structures provide insight into function. However, the dynamics that link extracellular sensing to intracellular signaling are not completely understood, because GPCRs used in structure determination are generally modified to constrain their dynamics. Josephs <jats:italic>et al.</jats:italic> succeeded in determining the structures of an unmodified calcitonin gene–related peptide receptor, which is implicated in migraines, both alone and bound to its neuropeptide ligand. Based on the structures and data from complementary biophysical techniques, they show that initial binding of the peptide causes only minor conformational changes of the GPCR, but dynamically causes changes at the intracellular side that facilitate G protein binding and activation. </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.abf7258">eabf7258</jats:related-article> </jats:p>

<jats:title>Light makes light work of fatty acids</jats:title> <jats:p> Photosynthetic organisms are notable for their ability to capture light energy and use it to power biosynthesis. Some algae have gone a step beyond photosynthesis and can use light to initiate enzymatic photodecarboxylation of fatty acids, producing long-chain hydrocarbons. To understand this transformation, Sorigué <jats:italic>et al.</jats:italic> brought to bear an array of structural, computational, and spectroscopic techniques and fully characterized the catalytic cycle of the enzyme. These experiments are consistent with a mechanism starting with electron transfer from the fatty acid to a photoexcited oxidized flavin cofactor. Decarboxylation yields an alkyl radical, which is then reduced by back electron transfer and protonation rather than hydrogen atom transfer. The wealth of experimental data explains how algae harness light energy to produce alka(e)nes and provides an appealing model system for understanding enzyme-catalyzed photochemistry more generally. </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.abd5687">eabd5687</jats:related-article> </jats:p>

<jats:p> Taniguchi <jats:italic>et al</jats:italic> . (Research Articles, 17 July 2020, p. 269) claim that the cytokine interleukin-33 induces accumulation of tumor-associated macrophages expressing the immunoglobulin E receptor FcεRI. Although these findings hold great therapeutic promise, we provide evidence that the anti-FcεRI antibody used in this study is not specific for FcεRI on macrophages, which raises concerns about the validity of some of the conclusions. </jats:p>

<jats:p>Amid the staggering amount of suffering and death during this historic pandemic of COVID-19, a remarkable success story stands out. The development of several highly efficacious vaccines against a previously unknown viral pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in less than 1 year from the identification of the virus is unprecedented in the history of vaccinology. A frequently asked question is how such an extraordinary accomplishment could have been realized in such a short time frame, when timelines for other vaccines are measured in years if not decades. In fact, concern about this truncated timeline has contributed in part to the hesitancy in accepting these vaccines. What is not fully appreciated is that the starting point of the timeline for SARS-CoV-2 vaccines was not 10 January 2020, when the Chinese published the genetic sequence of the virus. Rather, it began decades earlier, out of the spotlight.</jats:p>

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

<jats:p>President and lawmakers push proposals to add technology directorate and boost budget.</jats:p>

<jats:p>Reprise of storied experiment confirms muon's extra magnetism.</jats:p>

<jats:p>Ancient genomes from first moderns in Europe tell stories of diverse origins, ancient trysts.</jats:p>

<jats:p>Vaccine trial participants call for review after unusual private study found they have no virus-blocking antibodies.</jats:p>

<jats:p>University investigation finds anxiety expert pressured whistleblowers.</jats:p>