Widespread splicing of repetitive element loci into coding regions of gene transcripts.

We performed a thorough characterization of expressed repetitive element loci (RE) in the human orbitofrontal cortex (OFC) using directional RNA sequencing data. Considering only sequencing reads that map uniquely onto the human genome, we discovered that the overwhelming majority of intronic and exonic RE are expressed in the same orientation as the gene in which they reside. Our mapping approach enabled the identification of novel differentially expressed RE transcripts between the OFC and peripheral blood lymphocytes.

Repetitive elements and epigenetic marks in behavior and psychiatric disease.

Repetitive elements, which are relics of previous transposition events, constitute a large proportion of the human genome. The ability of transposons to gives rise to new DNA combinations has clearly provided an evolutionary advantage to their hosts. Transposons have shaped our genomes by giving rise to novel coding sequences, alternative gene promoters, conserved noncoding elements, and gene networks.

The Saccharomyces cerevisiae Nrd1-Nab3 transcription termination pathway acts in opposition to Ras signaling and mediates response to nutrient depletion.

The Saccharomyces cerevisiae Nrd1-Nab3 pathway directs the termination and processing of short RNA polymerase II transcripts. Despite the potential for Nrd1-Nab3 to affect the transcription of both coding and noncoding RNAs, little is known about how the Nrd1-Nab3 pathway interacts with other pathways in the cell. Here we present the results of a high-throughput synthetic lethality screen for genes that interact with NRD1 and show roles for Nrd1 in the regulation of mitochondrial abundance and cell size.

Transcriptome-wide binding sites for components of the Saccharomyces cerevisiae non-poly(A) termination pathway: Nrd1, Nab3, and Sen1.

RNA polymerase II synthesizes a diverse set of transcripts including both protein-coding and non-coding RNAs. One major difference between these two classes of transcripts is the mechanism of termination. Messenger RNA transcripts terminate downstream of the coding region in a process that is coupled to cleavage and polyadenylation reactions.

Yeast Nrd1, Nab3, and Sen1 transcriptome-wide binding maps suggest multiple roles in post-transcriptional RNA processing.

RNA polymerase II transcribes both coding and noncoding genes, and termination of these different classes of transcripts is facilitated by different sets of termination factors. Pre-mRNAs are terminated through a process that is coupled to the cleavage/polyadenylation machinery, and noncoding RNAs in the yeast Saccharomyces cerevisiae are terminated through a pathway directed by the RNA-binding proteins Nrd1, Nab3, and the RNA helicase Sen1. We have used an in vivo cross-linking approach to map the binding sites of components of the yeast non-poly(A) termination pathway.