Catálogo de publicaciones - revistas

<jats:title>Simply Folding</jats:title> <jats:p> RNA chaperones simplify what would otherwise be complex and slow RNA folding events. <jats:bold> Grohman <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6129" page="190" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1230715">190</jats:related-article> , published online 7 March) show that the Moloney murine leukemia virus (MuLV) nucleocapsid (NC) protein, which chaperones MuLV RNA dimerization promotes MuLV RNA folding by binding to exposed guanosine bases and destabilizing strong guanosine interactions. With base-pairs being rendered roughly of the same energy, RNA assembly pathways are simplified, promoting proper folding. </jats:p>

<jats:title>Variants and Regulation</jats:title> <jats:p> Genomic DNA is packaged into nucleosomes by spooling around histone proteins. Histone variants and the composition of nucleosomes can influence gene expression, as well as other chromatin-mediated processes. For example, the H2A.Z histone variant flanks RNA polII promoters, and such nucleosomes show rapid turnover, as well as enrichment for histone H3 acetylated at lysine 56 (H3-K56Ac). <jats:bold> Watanabe <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6129" page="195" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1229758">195</jats:related-article> ) show that H3-K56Ac alters the substrate specificity of the chromatin remodeling enzyme SWR-C, which normally evicts nucleosomal H2A.Z such that it now rapidly exchanges both canonical H2A and the variant H2A.Z, modulating nucleosome turnover and therefore influencing gene regulation. Pathways are dramatically simplified, promoting proper folding. </jats:p>

<jats:title>Hide-and-Seek Virus</jats:title> <jats:p> Human cytomegalovirus (HCMV) establishes latent infection in human progenitor dendritic cells, causing significant morbidity and mortality on reactivation, which may occur in transplantation patients who are immunosuppressed. Neither detection nor selective removal of rare latent HCMV-infected cells has been possible. <jats:bold> Weekes <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6129" page="199" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1235047">199</jats:related-article> ) have found that the multidrug-resistant ABC transporter, multidrug resistance–associated protein-1 (MRP1) is down-regulated during latent HCMV infection. Consequently, cytotoxic MRP1-specific substrates are not exported from HCMV-infected cells and accumulate—leading to cell death, which could potentially provide a mechanism for eliminating infected cells prior to transplantation. </jats:p>

<jats:title>INTERFER(ON)ing Persistence</jats:title> <jats:p> During persistent viral infections, a dysregulated immune response fails to control the infection. <jats:bold> Wilson <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6129" page="202" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1235208">202</jats:related-article> ) and <jats:bold> Teijaro <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6129" page="207" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1235214">207</jats:related-article> ; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6129" page="155" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1237568">Odorizzi and Wherry</jats:related-article> </jats:bold> ) show this occurs because type I interferons (IFN I), critical for early responses to viral infection, contribute to the altered immunity seen during persistent infection. Antibody blockade of IFN I signaling during chronic lymphocytic choriomeningitis virus (LCMV) in mice resulted in reduced viral titers at later stages of infection, reduced expression of inhibitory immune molecules and prevented the disruptions to secondary lymphoid organs typically observed during persistent infection with LCMV. Whether type I IFNs are also detrimental to persistent viral infection humans, such as HIV and hepatitis C virus, remains to be determined. </jats:p>

<jats:title>INTERFER(ON)ing Persistence</jats:title> <jats:p> During persistent viral infections, a dysregulated immune response fails to control the infection. <jats:bold> Wilson <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6129" page="202" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1235208">202</jats:related-article> ) and <jats:bold> Teijaro <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6129" page="207" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1235214">207</jats:related-article> ; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6129" page="155" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1237568">Odorizzi and Wherry</jats:related-article> </jats:bold> ) show this occurs because type I interferons (IFN I), critical for early responses to viral infection, contribute to the altered immunity seen during persistent infection. Antibody blockade of IFN I signaling during chronic lymphocytic choriomeningitis virus (LCMV) in mice resulted in reduced viral titers at later stages of infection, reduced expression of inhibitory immune molecules and prevented the disruptions to secondary lymphoid organs typically observed during persistent infection with LCMV. Whether type I IFNs are also detrimental to persistent viral infection humans, such as HIV and hepatitis C virus, remains to be determined. </jats:p>

<jats:title>The Smaller, the Better</jats:title> <jats:p> New semiconductor device technology enables injection of light-emitting diodes, silicon devices, actuators, and sensors at precisely controlled locations within biological tissues, such as the brain. <jats:bold> Kim <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6129" page="211" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1232437">211</jats:related-article> ) show how wireless control of animal models using these technologies and the techniques of optogenetics provide new insights into basic behavioral neuroscience. </jats:p>

<jats:title>Music Was My First Love</jats:title> <jats:p> Why do human beings enjoy music? <jats:bold> Salimpoor <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6129" page="216" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1231059">216</jats:related-article> ) combined behavioral economics with brain scanning to explore how a piece of music is considered rewarding to an individual when it is heard for the first time. They discovered that neural activity in the mesolimbic striatum during listening to a novel piece of music was the best predictor of the money listeners were willing to spend on buying the piece. These observations implicate sensory cortical areas in reward processing, which the authors attribute to the aesthetic nature of the judgment. </jats:p>

<jats:p>Think of any multiplexed biological technique. RT-PCR. DNA sequencing. Flow cytometry. Microscopy. All work on different principles. Yet all have one common factor: fluorescence. The ever-expanding variety of fluorescent molecules, nanoparticles, and proteins has expanded the palette, so to speak, of biological experimentation. The pages of research journals may be filled mostly with reds and greens, but today's researchers have literally dozens of hues available from which to choose. Such variety has expanded the spectrum of applications and instrumentation available to the research community. The future of fluorescence multiplexing has never seemed so, ahem, bright.</jats:p>

<jats:p>Listen to stories on locomotion in Australopithecus sediba, self-medicating animals, the hunt for dark matter, and more.</jats:p>

<jats:p>A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.</jats:p>