Project description:Chlorpyrifos is an organophosphorus insecticide that despite imposed restricitions on its use by the EPA, is one of the most commonly used insecticides. Although CPF is so widely used little is known about its effect on overall gene expression in vivo. DNA microarray technology was used to determine differential gene expression resulting from chlorpyrifos (CPF) exposure. Experiment Overall Design: Male Fisher 344 rats aged 11-12 weeks were treated with varying doses of chlorpyrifos (CPF) and terminally sacced at 96 hours post-exposure in three separate experiments. An approximate 30mg section of the frontal lobe of the brain was processed for total RNA extraction.
Project description:The 3′-ends of eukaryotic pre-mRNAs are processed in the nucleus by a large multiprotein complex, the cleavage and polyadenylation factor (CPF). CPF cleaves RNA, adds a poly(A) tail and signals transcription termination. CPF harbors four enzymatic activities essential for these processes but how these are coordinated remains poorly understood. Several subunits of the CPF including two protein phosphatases are also found in a related complex, the ‘associated with Pta1’ (APT) complex, but the relationship between CPF and APT is unclear. Here, we show that the APT complex is physically distinct from CPF. The 21 kDa Syc1 protein is associated only with APT, and not with CPF, and is therefore the defining subunit of APT. Using ChIP-seq, PAR-CLIP and RNA-seq, we show that Syc1 has functions separable from those of CPF. Syc1 plays a role in sn/snoRNA production whereas CPF processes the 3ʹ-ends of protein-coding pre-mRNAs. These results define distinct protein machineries for synthesis of mature eukaryotic protein-coding and non-coding RNAs.
Project description:The 3′-ends of eukaryotic pre-mRNAs are processed in the nucleus by a large multiprotein complex, the cleavage and polyadenylation factor (CPF). CPF cleaves RNA, adds a poly(A) tail and signals transcription termination. CPF harbors four enzymatic activities essential for these processes but how these are coordinated remains poorly understood. Several subunits of the CPF including two protein phosphatases are also found in a related complex, the ‘associated with Pta1’ (APT) complex, but the relationship between CPF and APT is unclear. Here, we show that the APT complex is physically distinct from CPF. The 21 kDa Syc1 protein is associated only with APT, and not with CPF, and is therefore the defining subunit of APT. Using ChIP-seq, PAR-CLIP and RNA-seq, we show that Syc1 has functions separable from those of CPF. Syc1 plays a role in sn/snoRNA production whereas CPF processes the 3ʹ-ends of protein-coding pre-mRNAs. These results define distinct protein machineries for synthesis of mature eukaryotic protein-coding and non-coding RNAs.