Catálogo de publicaciones - revistas

<jats:title>Putting vertebrate development on hold</jats:title> <jats:p> Suspended animation is an often-used device in science fiction, but it also exists in several forms in nature: hibernation, torpor, and diapause. Hu <jats:italic>et al.</jats:italic> studied diapause in the African turquoise killifish, a vertebrate model system (see the Perspective by Van Gilst). They found that diapause protects a complex living organism without trade-offs for future growth, fertility, and even life span. Diapause is actively regulated, with a dynamic switch to specific Polycomb complex members. One Polycomb member, CBX7, is critical for the regulation of organ genes and is involved in muscle preservation and diapause maintenance. This work illuminates the mechanisms that underlie suspended life. </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="6480" page="870" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aaw2601">870</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6480" page="851" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aba8064">851</jats:related-article> </jats:p>

<jats:title>Architecture of human BAF complex</jats:title> <jats:p> The SWI/SNF family chromatin remodelers regulate chromatin and transcription. The protein complexes BAF and PBAF are mammalian SWI/SNF remodelers that play essential functions in diverse developmental and physiological processes. He <jats:italic>et al.</jats:italic> determined the structure of the human BAF complex, which contains three modules that bind the nucleosome on the top, bottom, and side, making this nucleosome-recognition pattern distinct from other chromatin remodelers. Mutations in BAF that are frequently associated with human cancer cluster into a nucleosome-interacting region. This structure provides a framework for understanding the BAF-mediated chromatin remodeling mechanism and its dysregulation in cancer. </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="6480" page="875" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aaz9761">875</jats:related-article> </jats:p>

<jats:title>Choosing the drug to fit the protein</jats:title> <jats:p> Many approved drugs bind to G protein–coupled receptors (GPCRs). A challenge in targeting GPCRs is that different ligands preferentially activate different signaling pathways. Two papers show how biased signaling arises for the angiotensin II type 1 receptor that couples to two signaling partners (G proteins and arrestins). Suomivuori <jats:italic>et al.</jats:italic> used large-scale atomistic simulations to show that coupling to the two pathways is through two distinct GPCR conformations and that extracellular ligands favor one or the other conformation. Wingler <jats:italic>et al.</jats:italic> present crystal structures of the same receptor bound to ligands with different bias profiles. These structures show conformational changes in and around the binding pocket that match those observed in simulations. This work could provide a framework for the rational design of drugs that are more effective and have fewer side effects. </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="6480" page="881" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aaz0326">881</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6480" page="888" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aay9813">888</jats:related-article> </jats:p>

<jats:title>Choosing the drug to fit the protein</jats:title> <jats:p> Many approved drugs bind to G protein–coupled receptors (GPCRs). A challenge in targeting GPCRs is that different ligands preferentially activate different signaling pathways. Two papers show how biased signaling arises for the angiotensin II type 1 receptor that couples to two signaling partners (G proteins and arrestins). Suomivuori <jats:italic>et al.</jats:italic> used large-scale atomistic simulations to show that coupling to the two pathways is through two distinct GPCR conformations and that extracellular ligands favor one or the other conformation. Wingler <jats:italic>et al.</jats:italic> present crystal structures of the same receptor bound to ligands with different bias profiles. These structures show conformational changes in and around the binding pocket that match those observed in simulations. This work could provide a framework for the rational design of drugs that are more effective and have fewer side effects. </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="6480" page="881" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aaz0326">881</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6480" page="888" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aay9813">888</jats:related-article> </jats:p>

<jats:title>A nanoparticle trapped and cooled</jats:title> <jats:p> Cooling massive particles to the quantum ground state allows fundamental tests of quantum mechanics to be made; it would provide an experimental probe of the boundary between the classical and quantum worlds. Delić <jats:italic>et al.</jats:italic> laser-cooled an optically trapped solid-state object (a ∼150-nanometer-diameter silic a nanoparticle) into its quantum ground state of motion starting from room temperature. Because the object is levitated using optical forces, the experimental configuration can be switched to free fall, thereby providing a test bed for several macroscopic quantum experiments. </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="6480" page="892" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aba3993">892</jats:related-article> </jats:p>

<jats:title>Quantum anomalous Hall goes intrinsic</jats:title> <jats:p> Quantum anomalous Hall effect—the appearance of quantized Hall conductance at zero magnetic field—has been observed in thin films of the topological insulator Bi <jats:sub>2</jats:sub> Se <jats:sub>3</jats:sub> doped with magnetic atoms. The doping, however, introduces inhomogeneity, reducing the temperature at which the effect occurs. Two groups have now observed quantum anomalous Hall effect in intrinsically magnetic materials (see the Perspective by Wakefield and Checkelsky). Serlin <jats:italic>et al.</jats:italic> did so in twisted bilayer graphene aligned to hexagonal boron nitride, where the effect enabled the switching of magnetization with tiny currents. In a complementary work, Deng <jats:italic>et al.</jats:italic> observed quantum anomalous Hall effect in the antiferromagnetic layered topological insulator MnBi <jats:sub>2</jats:sub> Te <jats:sub>4</jats:sub> . </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="6480" page="900" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aay5533">900</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6480" page="895" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aax8156">895</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6480" page="848" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aba5313">848</jats:related-article> </jats:p>

<jats:title>Quantum anomalous Hall goes intrinsic</jats:title> <jats:p> Quantum anomalous Hall effect—the appearance of quantized Hall conductance at zero magnetic field—has been observed in thin films of the topological insulator Bi <jats:sub>2</jats:sub> Se <jats:sub>3</jats:sub> doped with magnetic atoms. The doping, however, introduces inhomogeneity, reducing the temperature at which the effect occurs. Two groups have now observed quantum anomalous Hall effect in intrinsically magnetic materials (see the Perspective by Wakefield and Checkelsky). Serlin <jats:italic>et al.</jats:italic> did so in twisted bilayer graphene aligned to hexagonal boron nitride, where the effect enabled the switching of magnetization with tiny currents. In a complementary work, Deng <jats:italic>et al.</jats:italic> observed quantum anomalous Hall effect in the antiferromagnetic layered topological insulator MnBi <jats:sub>2</jats:sub> Te <jats:sub>4</jats:sub> . </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="6480" page="900" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aay5533">900</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6480" page="895" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aax8156">895</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6480" page="848" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aba5313">848</jats:related-article> </jats:p>

<jats:title>Larger monolayers with gold tapes</jats:title> <jats:p> Although the exfoliation of monolayers of materials such as transition metal dichalcogenides produces high-quality electronic materials with low defect densities, the size of the monolayers is limited to the micrometer scale. Liu <jats:italic>et al.</jats:italic> modified this method by creating atomically flat gold layers on polymer supports. The strong van der Waals adhesion of the gold layer allowed monolayers to be exfoliated on the centimeter scale. Multilayers could be reassembled to artificial structures, such as a MoSe <jats:sub>2</jats:sub> /WSe <jats:sub>2</jats:sub> single-crystal bilayer with a twist angle chosen to quench intralayer exciton formation. </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="6480" page="903" related-article-type="in-this-issue" vol="367" xlink:href="10.1126/science.aba1416">903</jats:related-article> </jats:p>