Project description:Nuclear lamins contact the genome at the nuclear periphery through large domains and are involved in chromatin organization. Among broad peak calling algorithms available to date, none are suited for mapping lamin-genome interactions genome-wide. We disclose a novel algorithm, Enriched Domain Detector (EDD), for analysis of broad enrichment domains from ChIP-seq data. EDD enables discovery of genomic domains interacting with broadly distributed chromatin-associated proteins such as lamins. The main advantage of EDD over existing broad peak callers is sensitivity to domain width rather than enrichment strength at a particular site, and robustness against local variations. EDD is downloadable from http://github.com/eivindgl/edd. RNA-seq experiments in human normal dermal fibroblasts (Lonza CC-2511; LDFs) and human normal primary dermal fibroblasts (Norwegian Stem Cell Center AD04DFs).
Project description:Nuclear lamins contact the genome at the nuclear periphery through large domains and are involved in chromatin organization. Among broad peak calling algorithms available to date, none are suited for mapping lamin-genome interactions genome-wide. We disclose a novel algorithm, Enriched Domain Detector (EDD), for analysis of broad enrichment domains from ChIP-seq data. EDD enables discovery of genomic domains interacting with broadly distributed chromatin-associated proteins such as lamins. The main advantage of EDD over existing broad peak callers is sensitivity to domain width rather than enrichment strength at a particular site, and robustness against local variations. EDD is downloadable from http://github.com/eivindgl/edd. LMNA ChIP-seq experiments in human normal dermal fibroblasts (Lonza CC-2511; LDFs) and human normal primary dermal fibroblasts (Norwegian Stem Cell Center AD04DFs).
Project description:Nuclear lamins contact the genome at the nuclear periphery through large domains and are involved in chromatin organization. Among broad peak calling algorithms available to date, none are suited for mapping lamin-genome interactions genome-wide. We disclose a novel algorithm, Enriched Domain Detector (EDD), for analysis of broad enrichment domains from ChIP-seq data. EDD enables discovery of genomic domains interacting with broadly distributed chromatin-associated proteins such as lamins. The main advantage of EDD over existing broad peak callers is sensitivity to domain width rather than enrichment strength at a particular site, and robustness against local variations. EDD is downloadable from http://github.com/eivindgl/edd.
Project description:Nuclear lamins contact the genome at the nuclear periphery through large domains and are involved in chromatin organization. Among broad peak calling algorithms available to date, none are suited for mapping lamin-genome interactions genome-wide. We disclose a novel algorithm, Enriched Domain Detector (EDD), for analysis of broad enrichment domains from ChIP-seq data. EDD enables discovery of genomic domains interacting with broadly distributed chromatin-associated proteins such as lamins. The main advantage of EDD over existing broad peak callers is sensitivity to domain width rather than enrichment strength at a particular site, and robustness against local variations. EDD is downloadable from http://github.com/eivindgl/edd.
Project description:Mucin domains are densely O-glycosylated modular protein domains found in a wide variety of cell surface and secreted proteins. Mucin-domain glycoproteins are key players in a host of human diseases, especially cancer, but the scope of the mucinome remains poorly defined. Recently, we characterized a bacterial mucinase, StcE, and demonstrated that an inactive point mutant retains binding selectivity for mucins. In this work, we leveraged inactive StcE to selectively enrich and identify mucins from complex samples like cell lysate and crude ovarian cancer patient ascites fluid. Our enrichment strategy was further aided by an algorithm to assign confidence to mucin-domain glycoprotein identifications. This mucinomics platform facilitated detection of hundreds of glycopeptides from mucin domains and highly overlapping populations of mucin-domain glycoproteins from ovarian cancer patients. Ultimately, we demonstrate our mucinomics approach can reveal key molecular signatures of cancer from in vitro and ex vivo sources.
Project description:Histone modifications associated with gene silencing typically mark large contiguous regions of the genome forming repressive chromatin domain structures. Since the repressive domains exist in close proximity to active regions, maintenance of domain structure is critically important. This study shows that nickel, a nonmutagenic carcinogen, can disrupt histone H3 lysine 9 dimethylation (H3K9me2) domain structures genome-wide, resulting in spreading of H3K9me2 marks into the active regions, which is associated with gene silencing. Our results suggest inhibition of DNA binding of the insulator protein CCCTC-binding factor (CTCF) at the H3K9me2 domain boundaries as a potential reason for H3K9me2 domain disruption. These findings have major implications in understanding chromatin dynamics and the consequences of chromatin domain disruption during pathogenesis. Investigations into the genomic landscape of histone modifications in heterochromatic regions have revealed histone H3 lysine 9 dimethylation (H3K9me2) to be important for differentiation and maintaining cell identity. H3K9me2 is associated with gene silencing and is organized into large repressive domains that exist in close proximity to active genes, indicating the importance of maintenance of proper domain structure. Here we show that nickel, a nonmutagenic environmental carcinogen, disrupted H3K9me2 domains, resulting in the spreading of H3K9me2 into active regions, which was associated with gene silencing. We found weak CCCTC-binding factor (CTCF)-binding sites and reduced CTCF binding at the Ni-disrupted H3K9me2 domain boundaries, suggesting a loss of CTCF-mediated insulation function as a potential reason for domain disruption and spreading. We furthermore show that euchromatin islands, local regions of active chromatin within large H3K9me2 domains, can protect genes from H3K9me2-spreadingM-bM-^@M-^Sassociated gene silencing. These results have major implications in understanding H3K9me2 dynamics and the consequences of chromatin domain disruption during pathogenesis.