Browsing by Author "Patterton, Hugh"
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- ItemOpen AccessThe association of the secondary DNA-binding site of linker histone H5 in a nucleosome(2001) Koorsen, Gerrit; Patterton, HughIn order to understand the role of linker histones in the formation of the 30-run chromatin fibre as well as their role in transcriptional repression, it is essential to know their location on the nucleosome. In this study, we have modelled the location of the globular domain of chicken linker histone HS (GHS) on the nuc1eosome. The primary DNA binding site of GH5 was modelled by homology to the co-crystal structure of the E. coli CAP-DNA complex.
- ItemOpen AccessCharacterisation of the role of brain factor 1 in the olfactory neuroepithelium during neuronal development(2003) Linda, Pride; Illing, Nicola; Patterton, HughBrain Factor 1 (BF-1), a winged helix transcription factor, displays a restricted pattern of expression within the developing forebrain, playing a critical function in the regulation of neuronal progenitor cell proliferation and differentiation within the developing forebrain. The molecular mechanisms by which BF-1 carries out its function remain to be elucidated. Hence, this study aimed to investigate and characterise the molecular mechanisms by which BF-1 function is regulated during neuronal development.
- ItemOpen AccessCompaction of chromatin in Saccharomyces cerevisiae(2006) Chang, Cheng-Fu; Patterton, HughThis study investigated the link between the association of the yeast linker histone homologue, Hholp, and the compaction of the yeast genome during stationary phase. The relative gene content of condensed chromatin, fractionated and isolated by sucrose gradient ultracentrifugation from stationary and exponential phase cultures was compared using genome-wide technologies. This study showed that condensed chromatin of stationary phase culture contained an enriched density of genes on all the chromosomes, indicating global compaction of the yeast genome during stationary phase.
- ItemOpen AccessAn experimental approach to determine the binding mode of yeast linker histone, Hho1p(2003) Smith, Elizabeth M; Patterton, HughIn this study, we have developed an assay to investigate of the binding mode of yeast linker histone Hholp to nucleosomes, using magnetic bead pull-down assays. To understand the structural and regulatory role of, Hholp, the linker histone in Saccharomyces cerevisiae, and that of higher eukaryotes (Thoma et al., 1979), it is essential to determine the manner in which these histones associate with chromatin. It was previously proposed that Hh01p may bind to two nucleosomes simultaneously, where globular domain one and globular domain two bind to the adjacent nucleosomes.
- ItemOpen AccessGenomic distribution of histone H1 in budding yeast (Saccharomyces cerevisiae) : yeast chromosome III(2002) Priya, Vattem Padma; Patterton, HughThe linker histone HI binds to the nucleosome and is essential for the organization of nucleosomes into the 30-nm filament of the chromatin. This compaction of DNA has a well-characterized effect on DNA function. In Saccharomyces cerevisiae, HHO 1 encodes a putative linker histone with very significant homology to histone HI. In vitro chromatin assembly experiments with recombinant Hho 1 p have shown that it is able to complex with the dinucleosomes in a similar manner to histone HI. It has also been reported that disruption of HHOl has little affect on RNA levels. A longstanding issue concerns the location of Hho 1 p in the chromatin and studies have shown using immunoprecipitation technique with anti-HA antibody, that Hho 1 p shows a preferential binding to rDNA sequences. In this project we have tried to confirm the above results in wild type cells, using immunopurifi ed anti rHho 1 p antibody.
- ItemOpen AccessH3ABioNet, a sustainable pan-African bioinformatics network for human heredity and health in Africa(2016) Mulder, Nicola J; Adebiyi, Ezekiel; Alami, Raouf; Benkahla, Alia; Brandful, James; Doumbia, Seydou; Everett, Dean; Fadlelmola, Faisal M; Gaboun, Fatima; Gaseitsiwe, Simani; Ghazal, Hassan; Hazelhurst, Scott; Hide, Winston; Ibrahimi, Azeddine; Jaufeerally Fakim, Yasmina; Jongeneel, C Victor; Joubert, Fourie; Kassim, Samar; Kayondo, Jonathan; Kumuthini, Judit; Lyantagaye, Sylvester; Makani, Julie; Mansour Alzohairy, Ahmed; Masiga, Daniel; Moussa, Ahmed; Nash, Oyekanmi; Ouwe Missi Oukem-Boyer, Odile; Owusu-Dabo, Ellis; Panji, Sumir; Patterton, Hugh; Radouani, Fouzia; Sadki, KhalidThe application of genomics technologies to medicine and biomedical research is increasing in popularity, made possible by new high-throughput genotyping and sequencing technologies and improved data analysis capabilities. Some of the greatest genetic diversity among humans, animals, plants, and microbiota occurs in Africa, yet genomic research outputs from the continent are limited. The Human Heredity and Health in Africa (H3Africa) initiative was established to drive the development of genomic research for human health in Africa, and through recognition of the critical role of bioinformatics in this process, spurred the establishment of H3ABioNet, a pan-African bioinformatics network for H3Africa. The limitations in bioinformatics capacity on the continent have been a major contributory factor to the lack of notable outputs in high-throughput biology research. Although pockets of high-quality bioinformatics teams have existed previously, the majority of research institutions lack experienced faculty who can train and supervise bioinformatics students. H3ABioNet aims to address this dire need, specifically in the area of human genetics and genomics, but knock-on effects are ensuring this extends to other areas of bioinformatics. Here, we describe the emergence of genomics research and the development of bioinformatics in Africa through H3ABioNet.
- ItemOpen AccessInvestigations into the role of histone H2A ubiquitination in chromatin(1999) Jason, Laure Jeanine Monique; Lindsey, George G; Brandt, Wolf F; Patterton, HughAn in vitro system was used to determine the effect of histone H2A ubiquitination on linker histone binding to mononucleosomes. Hybrid octamers containing either H2A or ubiquitinated H2A (uH2A) were reconstituted onto random sequence 167 bp DNA. The affinity of the resultant nucleosome cores for linker histone H1 was determined from nucleoprotein gel shifts, protein analyses and thermal denaturation. Ubiquitinated H2A did not inhibit linker histone binding to nucleosome cores. The effect of uH2A on nucleosome and chromatosoine positioning on a 208 bp Lytechinus variegatus 5S rDNA fragment was investigated using a combination of micrococcal nuclease digestion and subsequent restriction enzyme digestion of the core particle or chromatosome DNA. Nucleosomes and chromatosomes containing uH2A were found to occupy the same positions on the template DNA as those containing H2A. Chromatin folding of nucleosomal arrays containing either H2A or uH2A was analysed using a quantitative agarose gel electrophoresis system developed by Hansen and co-workers. The extent of folding of nucleosomal arrays containing uH2A was comparable to that of control nucleosomal arrays. A differential centrifugation assay was used to monitor the extent of divalent cation induced oligomerisation of reconstituted nucleosomal arrays. Nucleosomal arrays containing uH2A were found to oligomerise at a lower magnesium concentration than control arrays. As a first step towards studying the effects of H2A ubiquitination in linker histone-bound nucleosomal arrays, a novel method for linker histone reconstitution onto long chromatin stripped of linker histones was developed. The fidelity of linker histone reconstitution was assayed by micrococcal nuclease digestion, thermal denaturation and determination of the orientation of neighbouring linker histone molecules in extended chromatin. In a separate study, the relationship between the observed repeat length of chromatin and the rate of micrococcal nuclease digestion was investigated. The repeat length of the same starting chromatin preparation at equivalent extents of digestion was found to vary according to the rate of digestion.
- ItemOpen AccessThe phosphorylation state of Saccharomyces cerevisiae linker histone Hho 1p during entry and exit of stationary phase(2005) Somers, Sachin J; Patterton, HughOur group has recently found that the linker histone Hh01 p of Saccharomyces cerevisiae exhibited a significant increase in binding to chromatin during stationary phase. Because of the role of H1 in gene expression and chromatin compaction, it is essential to understand the mechanism behind this change in binding behaviour for a complete mechanistic description of gene regulation. We postulated that the phosphorylation of serine or threonine residues decrease the affinity of H1 for DNA, resulting in the dissociation of H1 from chromatin in exponential phase. We investigated this possible change in the phosphorylation state of Hh01 p in yeast cells in exponential phase and in stationary phase by immunoprecipitation of Hh01 p, followed by western analysis using antiphosphoserine and anti-phosphothreonine antibodies.
- ItemOpen AccessThe role of set1 methylation of histone H3 lysine 4 on chromatin structure in Saccharomyces cerevisiae(2005) Mars, Rochan; Patterton, Hugh