Hannah Elisabeth Mischo

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Sen1 of S. cerevisiae is a known component of the NRD complex implicated in transcription termination of nonpolyadenylated as well as some polyadenylated RNA polymerase II transcripts. We now show that Sen1 helicase possesses a wider function by restricting the occurrence of RNA:DNA hybrids that may naturally form during transcription, when nascent RNA(More)
Eukaryotic genomes are extensively transcribed, forming both messenger RNAs (mRNAs) and noncoding RNAs (ncRNAs). ncRNAs made by RNA polymerase II often initiate from bidirectional promoters (nucleosome-depleted chromatin) that synthesize mRNA and ncRNA in opposite directions. We demonstrate that, by adopting a gene-loop conformation, actively transcribed(More)
Both RNA polymerase I and II (Pol I and Pol II) in budding yeast employ a functionally homologous "torpedo-like" mechanism to promote transcriptional termination. For two well-defined Pol II-transcribed genes, CYC1 and PMA1, we demonstrate that both Rat1p exonuclease and Sen1p helicase are required for efficient termination by promoting degradation of the(More)
Transcription termination of RNA polymerase II (Pol II) on protein-coding genes in S. cerevisiae relies on pA site recognition by 3' end processing factors. Here we demonstrate the existence of two alternative termination mechanisms that rescue polymerases failing to disengage from the template at pA sites. One of these fail-safe mechanisms is mediated by(More)
Formation of gamma-H2AX foci is a P. O.cellular response to genotoxic stress, such as DNA double strand breaks or stalled replication forks. Here we show that gamma-H2AX foci were also formed when cells were incubated with 0.5 microg/ml DNA intercalating agent actinomycin D. In untreated cells, gamma-H2AX co-immunoprecipitated with Ku70, a subunit of(More)
Termination of transcription by RNA polymerase II requires two distinct processes: The formation of a defined 3' end of the transcribed RNA, as well as the disengagement of RNA polymerase from its DNA template. Both processes are intimately connected and equally pivotal in the process of functional messenger RNA production. However, research in recent years(More)
Herpesvirus saimiri (HVS) encodes seven Sm-class small nuclear RNAs, called HSURs (for Herpesvirus saimiri U RNAs), that are abundantly expressed in HVS-transformed, latently infected marmoset T cells but are of unknown function. HSURs 1, 2, and 5 have highly conserved 5'-end sequences containing the AUUUA pentamer characteristic of AU-rich elements (AREs)(More)
Seven small nuclear RNAs of the Sm class are encoded by Herpesvirus saimiri (HVS), a gamma Herpesvirus that causes aggressive T cell leukemias and lymphomas in New World primates and efficiently transforms T cells in vitro. The Herpesvirus saimiri U RNAs (HSURs) are the most abundant viral transcripts in HVS-transformed, latently infected T cells but are(More)
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