ABSTRACT
Durante o período de isolamento social, realizado em virtude da pandemia de coronavírus, a audiencia das emissoras de rádio no Brasil aumentou. Mais uma vez, o meio de comunicaçao que é pautado pela simplicidade e baixo custo mostrou eficiencia como fonte de prestaçao de serviços, informaçao e também entretenimento. Este artigo discute a evoluçao do rádio ao longo de um século. De peça central nas salas de casa, passando pela mobilidade e instantaneidade, a chegada da comunicaçao em podcasts. Para preparar os profissionais que trabalham com o rádio, escolas de comunicaçao precisam estar atentas as mudanças tecnológicas e levar aos estudantes conhecimentos teóricos e práticos sobre a produçao de conteúdo em áudio. Como metodologia, foi feita a revisao bibliográfica sobre o tema, além da descriçao do estudo de caso sobre o ensino de radiojornalismo em uma Faculdade de Comunicaçao. Como principais resultados, destacamos que o rádio mantém uma grande relevancia como meio de baixo custo e grande audiencia, sendo que neste momento as novas tecnologías possibilitam a exploraçao de novos formatos. Destaca-se também que o rádio deixou de ser um veículo de comunicaçao de abrangencia regional - atualmente a produçao radiofónica tem alcance global, além disso, é marcada por elementos como a interatividade, multilateralidade, portabilidade, mobilidade e acesso e consumo individualizado.Alternate :During the period of social isolation, carried out due to the coronavirus pandemic, the audience of radio stations in Brazil increased. Once again, the means of communication-based on simplicity and low cost showed efficiency as a source of services, information, and entertainment. This article discusses the evolution of radio over a century. From the centerpiece in the homerooms, through mobility and instantaneous, to the arrival of communication in podcasts. To prepare radio professionals, communication schools need to be attentive to technological changes and provide students with theoretical and practical knowledge about the production of audio content. As a methodology, a bibliographic review on the topic was made, in addition to the description of the case study on teaching radio journalism at a Communication Faculty. As main results, we highlight that the radio maintains a vast relevance as a low-cost medium and an extensive audience, being that at this moment the new technologies allow the exploration of new formats. It is also noteworthy that radio is no longer a communication vehicle of regional scope - currently, radio production has a global reach, likewise, it is marked by elements such as interactivity, multilateralism, portability, mobility, and individualized access and consumption.
ABSTRACT
The replication transcription complex (RTC) from the virus SARS-CoV-2 is responsible for recognizing and processing RNA for two principal purposes. The RTC copies viral RNA for propagation into new virus and for ribosomal transcription of viral proteins. To accomplish these activities, the RTC mechanism must also conform to a large number of imperatives, including RNA over DNA base recognition, basepairing, distinguishing viral and host RNA, production of mRNA that conforms to host ribosome conventions, interfacing with error checking machinery, and evading host immune responses. In addition, the RTC will discontinuously transcribe specific sections of viral RNA to amplify certain proteins over others. Central to SARS-CoV-2 viability, the RTC is therefore dynamic and sophisticated. We have conducted a systematic structural investigation of three components that make up the RTC: Nsp7, Nsp8, and Nsp12 (also known as RNA-dependent RNA polymerase). We have solved high-resolution crystal structures of the Nsp7/8 complex, providing insight into the interaction between the proteins. We have used small-angle x-ray and neutron solution scattering (SAXS and SANS) on each component individually as pairs and higher-order complexes and with and without RNA. Using size exclusion chromatography and multiangle light scattering-coupled SAXS, we defined which combination of components forms transient or stable complexes. We used contrast-matching to mask specific complex-forming components to test whether components change conformation upon complexation. Altogether, we find that individual Nsp7, Nsp8, and Nsp12 structures vary based on whether other proteins in their complex are present. Combining our crystal structure, atomic coordinates reported elsewhere, SAXS, SANS, and other biophysical techniques, we provide greater insight into the RTC assembly, mechanism, and potential avenues for disruption of the complex and its functions.
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Models, Molecular , RNA, Viral/genetics , Scattering, Small Angle , Viral Nonstructural Proteins , Virus Replication , X-Ray DiffractionABSTRACT
Papain-like protease (PLpro) from SARS-CoV-2 plays essential roles in the replication cycle of the virus. In particular, it preferentially interacts with and cleaves human interferon-stimulated gene 15 (hISG15) to suppress the innate immune response of the host. We used small-angle X-ray and neutron scattering combined with computational techniques to study the mechanism of interaction of SARS-CoV-2 PLpro with hISG15. We showed that hISG15 undergoes a transition from an extended to a compact state after binding to PLpro, a conformation that has not been previously observed in complexes of SARS-CoV-2 PLpro with ISG15 from other species. Furthermore, computational analysis showed significant conformational flexibility in the ISG15 N-terminal domain, suggesting that it is weakly bound to PLpro and supports a binding mechanism that is dominated by the C-terminal ISG15 domain. This study fundamentally improves our understanding of the SARS-CoV-2 deISGylation complex that will help guide development of COVID-19 therapeutics targeting this complex.