Catálogo de publicaciones - revistas

<jats:title>Photosystem I enters into the spotlight</jats:title> <jats:p> Plants rely on large complexes of proteins, chlorophyll, and other cofactors to turn light into chemical energy. Qin <jats:italic>et al.</jats:italic> present the crystal structures of photosystem I (PSI) and the light-harvesting complex I (LHCI) supercomplex from pea plants (see the Perspective by Croce). The well-resolved structure of the outer antenna complexes and their interaction with the PSI core provide a structural basis for calculating excitation energy transfer efficiency. Moreover, the organization and orientation of chlorophyll and carotenoid cofactors within and between PSI and LHCI hint at energy transfer and photoprotection mechanisms. </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="6238" page="989" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aab0214">989</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6238" page="970" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aab3387">970</jats:related-article> </jats:p>

<jats:title>LEM gets T cells the energy they need</jats:title> <jats:p> During an infection, T cells proliferate extensively to build a sufficient army to defeat the invading pathogen. Carefully regulated changes in metabolism let T cells do this, but the specific nature of these changes is not fully understood. Using forward genetics in mice to screen for genes that regulate T cell immunity, Okoye <jats:italic>et al.</jats:italic> identified a mutation in the gene that encodes a protein they named lymphocyte expansion molecule (LEM) (see the Perspective by O'Sullivan and Pearce). LEM enhanced T cell immunity, including both proliferation and memory cell generation, in response to chronic viral infection. LEM facilitated these changes through effects on mitochondrial respiration. </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="6238" page="995" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa7516">995</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6238" page="976" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aac4997">976</jats:related-article> </jats:p>

<jats:title>An aromatic phosphorus and nitrogen ring</jats:title><jats:p>In chemistry, the term “aromatic” denotes the energy stabilization associated with electrons being shared among atoms in a ring. Benzene is the best-known aromatic compound, although numerous related hydrocarbons also manifest the property. Velian and Cummins now report a rare instance of an inorganic aromatic compound: a negatively charged pentagonal ring composed of three nitrogen and two phosphorus atoms.</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="6238" page="1001" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aab0204">1001</jats:related-article></jats:p>

<jats:title>Memory alloys that avoid exhaustion</jats:title> <jats:p> Shape memory alloys can pop back into shape after being deformed. However, often these alloys cannot cope with a large number of deformation cycles. Chluba <jats:italic>et al.</jats:italic> find an alloy that avoids this pitfall, deforming 10 million times with very little fatigue (see the Perspective by James). Such low-fatigue materials could be useful in a plethora of future applications ranging from refrigerators to artificial heart valves. </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="6238" page="1004" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.1261164">1004</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6238" page="968" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aab3273">968</jats:related-article> </jats:p>

<jats:title>Experimental recovery from retrograde amnesia</jats:title> <jats:p> When memory researchers induce amnesia, they normally assume that the manipulations prevent the memory engram from effective encoding at consolidation. In accordance with this, Ryan <jats:italic>et al.</jats:italic> found that after the injection of protein synthesis inhibitors, animals could not retrieve a memory. However, to their surprise, the memory could nevertheless be reactivated by light-induced activation of the neurons tagged during conditioning. Increased synaptic strength that is the result of cellular consolidation is thus not a critical requisite for storing a memory. </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="6238" page="1007" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa5542">1007</jats:related-article> </jats:p>

<jats:title>Sleep on it: Consolidating implicit learning</jats:title> <jats:p> A good night's sleep is one of the best ways to fix recently learned information into long-lasting memory. Recent evidence suggests that recent memories are reactivated during sleep and woven into existing representations of stored information. Hu <jats:italic>et al.</jats:italic> now demonstrate that triggering memory consolidation during sleep can help set into place recently learned anti-bias training (see the Perspective by Feld and Born). Changes in people's stereotypical attitudes toward race and gender were maintained for up to 1 week after training. </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="6238" page="1013" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa3841">1013</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6238" page="971" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aab4048">971</jats:related-article> </jats:p>