Biology subjects

Rowley, M. J.

Publications and source records attributed to Rowley, M. J..

2 recordsLinked to original sources

bioRxiv2019

Functional characterization of RNase H1 proteins in Arabidopsis thaliana

ABSTRACTRNase H1 is an endonuclease specific towards RNA:DNA hybrids. Members of this protein family are present in most living organisms and are essential for removing RNA that base pairs with DNA. It prevents detrimental effects of RNA:DNA hybrids and is involved in several biological processes. We show that Arabidopsis thaliana contains four RNase H1-like proteins originating from two gene duplication events and alternative splicing. These proteins have the canonical RNase H1 activity, which requires at least four ribonucleotides for activity. Two of those proteins are nuclear, one is localized to mitochondria and one to plastids. While the nuclear RNases H1 are dispensable, the presence of at least one organellar RNase H1 is required for embryonic development. The plastid protein RNH1C affects plastid DNA copy number and sensitivity to hydroxyurea. This indicates that three genomes present in each plant cell are served by at least one specialized RNase H1 protein.Competing Interest StatementThe authors have declared no competing interest.View Full Text

plant biology↗

bioRxiv2019

Immediate and deferred epigenomic signature of neuronal activation

Activity-driven transcription plays an important role in many brain processes, including those underlying memory and epilepsy. Here, we combine the genetic tagging of neuronal nuclei and ribosomes with various sequencing-based techniques to investigate the transcriptional and chromatin changes occurring at hippocampal excitatory neurons upon synchronous activation during status epilepticus and sparse activation during novel context exploration. The transcriptional burst, which affects both nucleus-resident non-coding RNAs and numerous protein-coding genes involved in neuroplasticity, is associated with a dramatic increase in chromatin accessibility of activity-regulated genes and enhancers, de novo binding of activity-regulated transcription factors, augmented promoter-enhancer interactions, and the formation of gene loops that bring together the TSS and TTS of strongly induced genes to sustain the fast re-loading of RNAPII complexes. Remarkably, some chromatin occupancy changes and interactions remain long after neuronal activation and may underlie the changes in neuronal responsiveness and circuit connectivity observed in these neuroplasticity paradigms.

neuroscience↗