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Articles 1 - 7 of 7

Full-Text Articles in Molecular Biology

Protein Degradation Regulates Phospholipid Biosynthetic Gene Expression In Saccharomyces Cerevisiae, Bryan Salas-Santiago Jan 2019

Protein Degradation Regulates Phospholipid Biosynthetic Gene Expression In Saccharomyces Cerevisiae, Bryan Salas-Santiago

Doctoral Dissertations

Transcriptional regulation of most phospholipid biosynthetic genes in Saccharomyces cerevisiae is coordinated by inositol and choline. Inositol affects phosphatidic acid (PA) intracellular levels. Opi1p interacts physically with PA and is the main repressor of the phospholipid biosynthetic genes. It is localized in the endoplasmic reticulum (ER) bound to the ER membrane protein Scs2p. When PA levels drop, Opi1p is translocated into the nucleus repressing most phospholipid biosynthetic genes. The OPI1 locus was identified in a screen looking for overproduction and excretion of inositol (Opi-). Opi- mutants are generally associated with a defect in repression of the ...


The Mitotic Genome: Accessibility And Transcriptional Control, Chris Hsiung Jan 2016

The Mitotic Genome: Accessibility And Transcriptional Control, Chris Hsiung

Publicly Accessible Penn Dissertations

Mitosis entails dramatic global alterations to genome structure and regulation, including

chromosome condensation, dissociation of the transcriptional machinery from chromosomes, and transcriptional silencing. Here I report studies that address the macromolecular accessibility of the mitotic genome and the control of transcriptional reactivation upon mitotic exit in a mammalian cell line. The results obtained from measuring the sensitivity of chromatin to DNase I cleavage by sequencing (DNase-seq) in pure mitotic cell populations demonstrate that macromolecular accessibility of the mitotic genome is widely preserved. Thus, steric hindrance from chromatin condensation is insufficient for explaining the eviction of transcription factors from mitotic chromatin ...


Functional Analysis Of The Ovarian Cancer Susceptibility Locus At 9p22.2 Reveals A Transcription Regulatory Network Mediated By Bnc2 In Ovarian Cells, Melissa Buckley Jan 2015

Functional Analysis Of The Ovarian Cancer Susceptibility Locus At 9p22.2 Reveals A Transcription Regulatory Network Mediated By Bnc2 In Ovarian Cells, Melissa Buckley

Graduate Theses and Dissertations

GWAS have identified several chromosomal loci associated with ovarian cancer risk. However, the mechanism underlying these associations remains elusive. We identify candidate functional Single Nucleotide Polymorphisms (SNPs) at the 9p22.2 ovarian cancer susceptibility locus, several of which map to transcriptional regulatory elements active in ovarian cells identified by FAIRE-seq (Formaldehyde assisted isolation of regulatory elements followed by sequencing) and ChIP-seq (Chromatin Immunoprecipitation followed by sequencing) in relevant cell types. Reporter and electrophoretic mobility shift assays (EMSA) determined the extent to which candidate SNPs had allele specific effects. Chromosome conformation capture (3C) reveals a physical association between Basonuclin 2 (BNC2 ...


Chromatin Insulators: Master Regulators Of The Eukaryotic Genome, Todd Andrew Schoborg Aug 2013

Chromatin Insulators: Master Regulators Of The Eukaryotic Genome, Todd Andrew Schoborg

Doctoral Dissertations

Proper organization of the chromatin fiber within the three dimensional space of the eukaryotic nucleus relies on a number of DNA elements and their interacting proteins whose structural and functional consequences exert significant influence on genome behavior. Chromatin insulators are one such example, where it is thought that these elements assist in the formation of higher order chromatin loop structures by mediating long-range contacts between distant sites scattered throughout the genome. Such looping serves a dual role, helping to satisfy both the physical constraints needed to package the linear DNA polymer within the small volume of the nucleus while simultaneously ...


Epigenomic And Transcriptional Regulation Of Hepatic Metabolism By Rev-Erb And Hdac3, Dan Feng Jan 2013

Epigenomic And Transcriptional Regulation Of Hepatic Metabolism By Rev-Erb And Hdac3, Dan Feng

Publicly Accessible Penn Dissertations

Metabolic activities are regulated by the circadian clock, and disruption of the clock exacerbates metabolic diseases including obesity and diabetes. Transcriptomic studies in metabolic organs suggested that the circadian clock drives the circadian expression of important metabolic genes. Here we show that histone deacetylase 3 (HDAC3) is recruited to the mouse liver genome in a circadian manner. Histone acetylation is inversely related to HDAC3 binding, and this rhythm is lost when HDAC3 is absent. Diurnal recruitment of HDAC3 corresponds to the expression pattern of REV-ERBĪ±, an important component of the circadian clock. REV-ERBĪ± colocalizes with HDAC3 near genes regulating lipid ...


Higher-Order Chromatin Organization In Hematopoietic Transcription, Wulan Deng Jan 2012

Higher-Order Chromatin Organization In Hematopoietic Transcription, Wulan Deng

Publicly Accessible Penn Dissertations

Coordinated transcriptional networks underlie complex developmental processes. Transcription factors play central roles in such networks by binding to core promoters and regulatory elements and thereby controlling transcription activities and chromatin states in the genome. GATA1 is a hematopoietic transcription factor that controls multiple hematopoietic lineages by activating and repressing gene expression, yet the in vivo mechanisms that specify these opposing activities are unknown. By examining the composition of GATA1 associated protein complexes in a genetic complementary erythroid cell system as well as through the use of tiling arrays, we found that a multi-protein complex containing SCL/TAL1, LMO2, Ldb1, and ...


Rna Polymerase Ii-Mediated Transcription At Active Loci Does Not Require Histone H3s10 Phosphorylation In Drosophila, Weili Cai, Xiaomin Bao, Huai Deng, Ye Jin, Jack Girton, Jorgen Johansen, Kristen M. Johansen Jan 2008

Rna Polymerase Ii-Mediated Transcription At Active Loci Does Not Require Histone H3s10 Phosphorylation In Drosophila, Weili Cai, Xiaomin Bao, Huai Deng, Ye Jin, Jack Girton, Jorgen Johansen, Kristen M. Johansen

Biochemistry, Biophysics and Molecular Biology Publications

JIL-1 is the major kinase controlling the phosphorylation state of histone H3S10 at interphase in Drosophila. In this study, we used three different commercially available histone H3S10 phosphorylation antibodies, as well as an acid-free polytene chromosome squash protocol that preserves the antigenicity of the histone H3S10 phospho-epitope, to examine the role of histone H3S10 phosphorylation in transcription under both heat shock and non-heat shock conditions. We show that there is no redistribution or upregulation of JIL-1 or histone H3S10 phosphorylation at transcriptionally active puffs in such polytene squash preparations after heat shock treatment. Furthermore, we provide evidence that heat shock-induced ...