Project description:Yeast Hmo1 ChIP-chip in triplicate with single untagged control Yeast Hmo1 ChIP-chip was performed in yDH419 (Hmo1-3myc) in triplicate using anti-myc (9E10 monoclonal antibody). A control experiment was performed using the untagged isogenic strain, BY4742
Project description:The purpose of this study was to investigate the role of the yeast protein, high mobility group protein (Hmo1), in rRNA synthesis. For over twenty years, Hmo1 has been proposed to be an activator of transcription by Pol I, but its regulatory mechanism remains largely undefined. Therefore, we used native elongating transcript sequencing (NET-seq) to explore the role of this factor in transcription by Pol I. Our NET-seq results demonstrated that in cells lacking Hmo1 (hmo1D), Pol I occupancy was significantly increased across the rDNA template, indicating an increased pause propensity in these cells. These data suggest that Hmo1 is an important transcription elongation factor for Pol I.
Project description:DNA topoisomerase-2 and high mobility group protein Hmo1 are known to regulate chromatin architecture by regulating gene boundaries. Here we report how these proteins affect global RNA level after inactivation of Top2 and Hmo1. Our data indicate that inactivating Hmo1 has a drastic effect on transcription levels of 20% yeast genes, however, this phenomenon can slightly be rescued by inactivating Top2 functions. Also, we study the Top2 and Top1 role in nucleosome architecture with and without expressing E.coli TopA. In top2-1;top1∆ condition with TopA expressed, it affects the nucleosome occupancy at the global level compared with top2-1;top1∆-Control plasmid. The ChIA-PET (Chromatin interaction analysis by paired-end tag sequencing) method is used to address whether a specific protein is engaged in the chromosomal interactions. Epitope tagged Top2 protein is used as probe in ChIA-PET experiments to map Top2 mediated chromatin-chromatin interactions.
Project description:Yeast Hog1-3HA ChIP-Chip in triplicate Keywords: ChIP-Chip Yeast Hog1 ChIP-Chip was performed in MAP51 (3HA-Hog1) in triplicate using anti-HA (12CA5 monoclonal antibody)
Project description:Specialized topoisomerases solve the topological constraints arising when replication forks encounter transcription. We have investigated Top2 contribution in S phase transcription. Specifically in S phase, Top2 binds intergenic regions close to transcribed genes without influencing their transcription. The Top2-bound loci exhibit low nucleosome density and accumulate yH2A when Top2 is defective. These intergenic loci associate with the HMG-protein Hmo1 throughout the cell cycle and are refractory to the histone variant Htz1. In top2 mutants, Hmo1 is deleterious and accumulates at pericentromeric regions in G2/M. Our data indicate that Top2 is dispensable for transcription and that Hmo1 and Top2 bind in the proximity of genes transcribed in S phase suppressing chromosome fragility at the M-G1 transition. We propose that an Hmo1-dependent epigenetic signature together with Top2 mediate a S-phasen architectural pathway controlling replicon dynamics when forks encounter transcriptionto preserve genome integrity. Signal tracks in BED format suitable for visualization on the UCSC genome browser can be found at http://bio.ifom-ieo-campus.it/supplementary/Bermejo_et_al_CELL_2009