Catálogo de publicaciones - revistas

<jats:title>Pre-MicroRNA Export Machinery</jats:title> <jats:p> Micro (mi) RNAs play a role in the regulation of many biological processes. Long transcripts are initially processed in the nucleus to yield pre-miRNAs that are translocated through the nuclear pore complex and further processed to mature miRNAs in the cytoplasm. <jats:bold> Okada <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="1275" related-article-type="in-this-issue" vol="326" xlink:href="10.1126/science.1178705">1275</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="5957" page="1195" related-article-type="in-this-issue" vol="326" xlink:href="10.1126/science.1183273">Stewart</jats:related-article> </jats:bold> ) describe the crystal structure of pre-miRNA complexed with the exportin Exp5 and the small nuclear GTPase RanGTP. The structure shows that Exp5 and RanGTP protect the miRNA from degradation by nucleases, as well as facilitate transport to the cytoplasm. RNA recognition is mainly through ionic interactions that are sequence independent, and model-building suggests that this nuclear export machinery could accommodate other small-structured RNAs. </jats:p>

<jats:title>RSV in 3D</jats:title> <jats:p> Respiratory syncytial virus (RSV) causes pneumonia and bronchiolitis in infants. RSV is an RNA virus in which the genomic RNA forms part of a nuclease-resistant helical ribonucleoprotein complex. <jats:bold> Tawar <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="1279" related-article-type="in-this-issue" vol="326" xlink:href="10.1126/science.1177634">1279</jats:related-article> ) now use x-ray and electron microscopy data to model the structure of this nucleocapsid complex and show how it can template RNA synthesis. The crystal structure shows RNA wrapped around a decameric ring of nucleocapsid protein. Combining this structure with electron microscopy data gives a model that shows how polymerase might read out the RNA bases without disassembling the nucleocapsid helix. </jats:p>

<jats:p>Microarrays are a vital tool in research on microRNAs, the tiny noncoding stretches of genetic material that regulate messenger RNA. They can't be beat for reading the microRNA "fingerprints" unique to disease states. But keeping up with this super hot field is a challenge for commercial microarray makers, and competition is fierce.</jats:p>

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

<jats:p>The show includes speciation by sexual selection, a Medieval Climate Anomaly, the fate of stimulus funding for science, and more.</jats:p>