Biochemistry, Biophysics, and Structural Biology Commons^™

P53 Drives A Transcriptional Program That Elicits A Non-Cell-Autonomous Response And Alters Cell State In Vivo, Sydney Moyer

Dissertations & Theses (Open Access)

Cell stress and DNA damage activate the tumor suppressor p53, triggering transcriptional activation of a myriad of target genes. The molecular, morphological, and physiological consequences of this activation remain poorly understood in vivo. We activated a p53 transcriptional program in mice by deletion of Mdm2, a gene which encodes the major p53 inhibitor. By overlaying tissue-specific RNA-sequencing data from pancreas, small intestine, ovary, kidney, and heart with existing p53 ChIP-sequencing, we identified a large repertoire of tissue-specific p53 genes and a common p53 transcriptional signature of seven genes which included Mdm2 but not p21. Global p53 activation …

New Mechanisms That Regulate Dna Double-Strand Break-Induced Gene Silencing And Genome Integrity, Dante Francis Deascanis

USF Tampa Graduate Theses and Dissertations

Proliferating cells are constantly threatened by genotoxic stressors that can potentially lead to genomic instability. Breaks in the DNA, namely double-strand breaks, are detrimental sources of damage that must be repaired to maintain genomic integrity and prevent potential tumorigenesis. Here we discuss a gene silencing mechanism flanking damaged chromatin. Gene silencing and transcriptional repression at damaged DNA are necessary to prevent potential genomic aberrations from occurring through conflicts with the DNA repair machinery. BMI1, a core polycomb protein in the polycomb repressive complex 1 (PRC1) has been known to play a role in gene silencing at damaged chromatin. However, the …

Calcineurin, Trevor P. Creamer

Molecular and Cellular Biochemistry Faculty Publications

The serine/threonine phosphatase calcineurin acts as a crucial connection between calcium signaling the phosphorylation states of numerous important substrates. These substrates include, but are not limited to, transcription factors, receptors and channels, proteins associated with mitochondria, and proteins associated with microtubules. Calcineurin is activated by increases in intracellular calcium concentrations, a process that requires the calcium sensing protein calmodulin binding to an intrinsically disordered regulatory domain in the phosphatase. Despite having been studied for around four decades, the activation of calcineurin is not fully understood. This review largely focuses on what is known about the activation process and highlights aspects …

Changes In Gene Expression Profiles In Müller Glia Following Exposure To An Α7 Nicotinic Acetylcholine Receptor Agonist, Megan L. Stanchfield

Masters Theses

Previous studies from this lab have determined that dedifferentiation of Müller glia (MG) occurs after application of an α7 nicotinic acetylcholine receptor agonist, PNU-282987 (PNU), to retinal pigment epithelial (RPE) cells in adult rodents. This study was designed to explore the role of the HB-EGF/Ascl1/Lin28a signaling pathway in MG dedifferentiation to retinal progenitor cells. RNAseq was performed on MG following contact with RPE-J cells treated with PNU-282987. Up- or down-regulated genes were compared with published literature of MG dedifferentiation that occurs in lower vertebrate regeneration or with transcript profiles during early mammalian development. Between 8-12 hours, up-regulation was observed in …

Genome Maintenance Roles Of Polycomb Transcriptional Repressors Bmi1 And Rnf2, Anthony Richard Sanchez Iv

USF Tampa Graduate Theses and Dissertations

The coordination of transcription, replication, and DNA damage response (DDR) is vital for maintaining normal cellular homeostasis. All of these processes take place on the chromatin and thus, the temporal and spatial separation of the factors responsible are necessary for each to be correctly completed. Here we detail several novel processes contributing to this network.

BMI1 is a component of the Polycomb Repressive Complex 1 (PRC1) which plays a key role in maintaining epigenetic silencing programs during development. Recently, BMI1 and other members of PRC1 like RNF2 have been implicated gene silencing during the DDR; however, the mechanism through which …

Probing The Limits Of Singular Gene Expression Through The Activity Of High Representation Odorant Receptor Transgenes, Eugene Lempert

Dissertations, Theses, and Capstone Projects

Singular gene expression is a common phenomenon in biology, making its appearance in immunoglobulin selection, protocadherin expression, X chromosome-inactivation, random monoallelic expression, and olfactory receptor choice. Singularity involves an activation and a feedback step. The mechanisms of singular gene choice have some capacity to integrate additional member genes while still maintaining singularity, but will activate an additional member if an earlier choice was incapable of triggering the feedback step. Odorant Receptor (OR) genes are substantially divergent from each other in terms of coding sequence, promoter structure, and genomic locus, all of which plays a role in how many Olfactory Sensory …

Investigating The Redox Sensitivity Of Mitf Splice Variants, Rachel Berryman

Senior Theses

Within pigment-producing cells known as melanocytes, the transcription factor MITF is intimately involved in regulating genes associated with cell cycle maintenance and melanocyte differentiation. Research, however, has provided conflicting results on the relationship between the expression levels of MITF and melanocyte cell fate. To complicate matters, two splice variants of MITF exist, differing by only 18 base pairs. These variants have been observed at variable levels of expression in melanocyte and melanoma cells, raising the question as to their functional purpose. Building upon previous research by the Leachman/Cassidy lab that identified the redox sensitivity of MITF while additionally establishing a …

Characterization Of Drosophila Boundary Element Associated Factor Beaf-32b Interactions With Transcription Factors And Chromatin Remodeling Complexes., Yuankai Dong

LSU Doctoral Dissertations

BEAF (Boundary Element-Associated Factor) was originally identified as a chromatin domain insulator binding protein, suggesting that it might play a role in linking gene regulation to chromatin organization and dynamics. Genome-wide mapping found that BEAF is usually found near transcription start sites, often of housekeeping genes, suggesting that it might play a role in promoter function. This would be a nontraditional role for an insulator binding protein. To gain insight into molecular mechanisms of BEAF function, we identified proteins that interact with BEAF using yeast 2-hybrid assays. Here we focus on three identified transcription factors: Bcd, Scr and Sry-δ. Interactions …

Termination-Independent Role Of Rat1 In Cotranscriptional Splicing In Budding Yeast, Zuzer Hakimuddin Dhoondia

Wayne State University Dissertations

Rat1 is a 5′→3′ exoribonuclease in budding yeast belonging to the XRN-family of nucleases. It is a highly conserved protein with homologs being present in fission yeast, flies, worms, mice and humans. Rat1 and its homolog in metazoan have been shown to function in multiple facets of RNA metabolism. In this study, we report a novel role of Rat1 in splicing of pre-mRNA in budding yeast. In the absence of the functional Rat1 in the nucleus, an increase in the level of unspliced transcripts was observed in yeast cells. Strand-specific TRO analysis revealed that the accumulation of unspliced transcripts upon …

Launching The Next Generation : Transcriptional Regulation During Oogenesis, Alicia K. Mccarthy

Legacy Theses & Dissertations (2009 - 2024)

Germ cells give rise to gametes and link generations by passing genetic information from parent to offspring. Gametes arise from, in many sexually reproducing organisms, germline stem cells (GSCs) which are set aside early during development. GSCs have an amazing capacity to undergo self-renewal to give rise to a pool of undifferentiated cells, while also differentiating to generate specialized germ cells such as haploid gametes. Upon female GSC differentiation, mitotically dividing germ cells can initiate meiosis, and mature within a follicle. During maturation, the specified oocyte is provided with a trust fund of RNAs and proteins for the next generation …

Characterization Of The Dyrk1a Protein-Protein Interaction Network, Varsha Ananthapadmanabhan

Theses and Dissertations

Human Dual specificity tyrosine (Y)-Regulated Kinase 1A (DYRK1A) is a protein kinase encoded by a dosage-dependent gene. An extra copy of DYRK1A contributes to Down syndrome (DS) pathogenesis while loss of one allele causes severe mental retardation and autism. DYRK1A is involved in phosphorylation of several proteins that regulate cell cycle control and tumor suppression. However, the function and regulation of this kinase is not well understood and current knowledge does not fully explain dosage-dependent function of this important kinase. Our previous proteomic studies identified several novel DYRK1A interacting proteins including RNF169, FAM117B, TROAP, LZTS1, LZTS2 and DCAF7. In this …