RESUMO
Eukaryotic gene expression is extensively regulated by cellular stress and pathogen infections. We have previously shown that herpes simplex virus 1 (HSV-1) and several cellular stresses cause widespread disruption of transcription termination (DoTT) of RNA polymerase II (RNAPII) in host genes and that the viral immediate early factor ICP27 plays an important role in HSV-1-induced DoTT. Here, we show that HSV-1 infection also leads to widespread changes in alternative polyadenylation (APA) of host mRNAs. In the majority of cases, polyadenylation shifts to upstream poly(A) sites (PAS), including many intronic PAS. Mechanistically, ICP27 contributes to HSV-1-mediated APA regulation. HSV-1- and ICP27-induced activation of intronic PAS is sequence-dependent and does not involve general inhibition of U1 snRNP. HSV1-induced intronic polyadenylation is accompanied by early termination of RNAPII. HSV-1-induced mRNAs polyadenylated at intronic PAS (IPA) are exported into the cytoplasm while APA isoforms with extended 3' UTRs are sequestered in the nuclei, both preventing the expression of the full-length gene products. Finally we provide evidence that HSV-induced IPA isoforms are translated. Together with other recent studies, our results suggest that viral infection and cellular stresses induce a multi-faceted host response that includes DoTT and changes in APA profiles.
Assuntos
Regulação da Expressão Gênica , Herpes Simples/genética , Herpes Simples/virologia , Herpesvirus Humano 1/fisiologia , Interações Hospedeiro-Patógeno/genética , RNA Mensageiro/genética , Perfilação da Expressão Gênica , Humanos , Modelos Biológicos , Poliadenilação , Isoformas de RNA , Transporte de RNA , Transcrição Gênica , TranscriptomaRESUMO
Viral tracers are important tools for neuroanatomical mapping and genetic payload delivery. Genetically modified viruses allow for cell-type-specific targeting and overcome many limitations of non-viral tracers. Here, we summarize the viruses that have been developed for neural circuit mapping, and we provide a primer on currently applied anterograde and retrograde viral tracers with practical guidance on experimental uses. We also discuss and highlight key technical and conceptual considerations for developing new safer and more effective anterograde trans-synaptic viral vectors for neural circuit analysis in multiple species.
Assuntos
Conectoma/métodos , Técnicas de Rastreamento Neuroanatômico/métodos , Sinapses/fisiologia , Vírus/genética , Animais , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Humanos , Vias Neurais/citologia , Vias Neurais/fisiologia , Sinapses/metabolismo , Vírus/metabolismoAssuntos
Negro ou Afro-Americano , Microbiologia/normas , Publicações Periódicas como Assunto/normas , Racismo/prevenção & controle , Disparidades em Assistência à Saúde/estatística & dados numéricos , Disparidades em Assistência à Saúde/tendências , Humanos , Publicações Periódicas como Assunto/tendências , Racismo/estatística & dados numéricos , Racismo/tendênciasAssuntos
Negro ou Afro-Americano , Microbiologia/estatística & dados numéricos , Pesquisa Biomédica/estatística & dados numéricos , Doenças Transmissíveis/epidemiologia , Doenças Transmissíveis/etnologia , Políticas Editoriais , Disparidades nos Níveis de Saúde , Humanos , Microbiologia/organização & administração , Publicações Periódicas como AssuntoRESUMO
Infection by viruses, including herpes simplex virus-1 (HSV-1), and cellular stresses cause widespread disruption of transcription termination (DoTT) of RNA polymerase II (RNAPII) in host genes. However, the underlying mechanisms remain unclear. Here, we demonstrate that the HSV-1 immediate early protein ICP27 induces DoTT by directly binding to the essential mRNA 3' processing factor CPSF. It thereby induces the assembly of a dead-end 3' processing complex, blocking mRNA 3' cleavage. Remarkably, ICP27 also acts as a sequence-dependent activator of mRNA 3' processing for viral and a subset of host transcripts. Our results unravel a bimodal activity of ICP27 that plays a key role in HSV-1-induced host shutoff and identify CPSF as an important factor that mediates regulation of transcription termination. These findings have broad implications for understanding the regulation of transcription termination by other viruses, cellular stress and cancer.