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Articles 1 - 9 of 9

Full-Text Articles in Molecular Biology

Identification Of Deubiquitinating Enzymes That Control The Cell Cycle In Saccharomyces Cerevisiae, Claudine E. Mapa Nov 2018

Identification Of Deubiquitinating Enzymes That Control The Cell Cycle In Saccharomyces Cerevisiae, Claudine E. Mapa

GSBS Dissertations and Theses

A large fraction of the proteome displays cell cycle-dependent expression, which is important for cells to accurately grow and divide. Cyclical protein expression requires protein degradation via the ubiquitin proteasome system (UPS), and several ubiquitin ligases (E3) have established roles in this regulation. Less is understood about the roles of deubiquitinating enzymes (DUB), which antagonize E3 activity. A few DUBs have been shown to interact with and deubiquitinate cell cycle-regulatory E3s and their protein substrates, suggesting DUBs play key roles in cell cycle control. However, in vitro studies and characterization of individual DUB deletion strains in yeast suggest that these ...


Identification Of Factors Involved In 18s Nonfunctional Ribosomal Rna Decay And A Method For Detecting 8-Oxoguanosine By Rna-Seq, Kelly A. Limoncelli Dec 2017

Identification Of Factors Involved In 18s Nonfunctional Ribosomal Rna Decay And A Method For Detecting 8-Oxoguanosine By Rna-Seq, Kelly A. Limoncelli

GSBS Dissertations and Theses

The translation of mRNA into functional proteins is essential for all life. In eukaryotes, aberrant RNAs containing sequence features that stall or severely slow down ribosomes are subject to translation-dependent quality control. Targets include mRNAs encoding a strong secondary structure (No-Go Decay; NGD) or stretches of positively-charged amino acids (Peptide-dependent Translation Arrest/Ribosome Quality Control; PDTA/RQC), mRNAs lacking an in-frame stop codon (Non-Stop Decay; NSD), or defective 18S rRNAs (18S Nonfunctional rRNA Decay; 18S NRD). Previous work from our lab showed that the S. cerevisiae NGD factors DOM34 and HBS1, and PDTA/RQC factor ASC1, all participate in the ...


Single-Molecule Studies Of Replication Kinetics In Response To Dna Damage, Divya Ramalingam Iyer May 2017

Single-Molecule Studies Of Replication Kinetics In Response To Dna Damage, Divya Ramalingam Iyer

GSBS Dissertations and Theses

In response to DNA damage during S phase, cells slow DNA replication. This slowing is orchestrated by the intra-S checkpoint and involves inhibition of origin firing and reduction of replication fork speed. Slowing of replication allows for tolerance of DNA damage and suppresses genomic instability. Although the mechanisms of origin inhibition by the intra-S checkpoint are understood, major questions remain about how the checkpoint regulates replication forks: Does the checkpoint regulate the rate of fork progression? Does the checkpoint affect all forks, or only those encountering damage? Does the checkpoint facilitate the replication of polymerase-blocking lesions? To address these questions ...


Three-Dimensional Folding Of Eukaryotic Genomes, Tsung-Han S. Hsieh May 2017

Three-Dimensional Folding Of Eukaryotic Genomes, Tsung-Han S. Hsieh

GSBS Dissertations and Theses

Chromatin packages eukaryotic genomes via a hierarchical series of folding steps, encrypting multiple layers of epigenetic information, which are capable of regulating nuclear transactions in response to complex signals in environment. Besides the 1-dimensinal chromatin landscape such as nucleosome positioning and histone modifications, little is known about the secondary chromatin structures and their functional consequences related to transcriptional regulation and DNA replication. The family of chromosomal conformation capture (3C) assays has revolutionized our understanding of large-scale chromosome folding with the ability to measure relative interaction probability between genomic loci in vivo. However, the suboptimal resolution of the typical 3C techniques ...


Optimizing Rna Library Preparation To Redefine The Translational Status Of 80s Monosomes: A Dissertation, Erin E. Heyer Oct 2015

Optimizing Rna Library Preparation To Redefine The Translational Status Of 80s Monosomes: A Dissertation, Erin E. Heyer

GSBS Dissertations and Theses

Deep sequencing of strand-specific cDNA libraries is now a ubiquitous tool for identifying and quantifying RNAs in diverse sample types. The accuracy of conclusions drawn from these analyses depends on precise and quantitative conversion of the RNA sample into a DNA library suitable for sequencing. Here, we describe an optimized method of preparing strand-specific RNA deep sequencing libraries from small RNAs and variably sized RNA fragments obtained from ribonucleoprotein particle footprinting experiments or fragmentation of long RNAs. Because all enzymatic reactions were optimized and driven to apparent completion, sequence diversity and species abundance in the input sample are well preserved ...


Small Rnas And Argonautes Provide A Paternal Epigenetic Memory Of Germline Gene Expression To Promote Thermotolerant Male Fertility: A Dissertation, Colin C. Conine Sep 2014

Small Rnas And Argonautes Provide A Paternal Epigenetic Memory Of Germline Gene Expression To Promote Thermotolerant Male Fertility: A Dissertation, Colin C. Conine

GSBS Dissertations and Theses

During each life cycle, gametes must preserve and pass on both genetic and epigenetic information, making the germline both immortal and totipotent. In the male germline the dramatic morphological transformation of a germ cell through meiosis, into a sperm competent for fertilization, while retaining this information is an incredible example of cellular differentiation. This process of spermatogenesis is inherently thermosensitive in numerous metazoa ranging from worms to man. Here, I describe the role of two redundant AGO-class paralogs, ALG-3/4, and their small RNA cofactors, in promoting thermotolerant male fertility in Caenorhabditis elegans. alg-3/4 double mutants exhibit temperature dependent ...


Evolutionary Approaches To The Study Of Small Noncoding Regulatory Rna Pathways: A Dissertation, Alfred T. Simkin Jul 2014

Evolutionary Approaches To The Study Of Small Noncoding Regulatory Rna Pathways: A Dissertation, Alfred T. Simkin

GSBS Dissertations and Theses

Short noncoding RNAs play roles in regulating nearly every biological process, in nearly every organism, yet the exact function and importance of these molecules remains a subject of some debate. In order to gain a better understanding of the contexts in which these regulators have evolved, I have undertaken a variety of approaches to study the evolutionary history of the components that make up these pathways, in the form of two main research efforts. In the first chapter, I have used a combination of population genetics and molecular evolution techniques to show that proteins involved in the piRNA pathway are ...


A Novel Role Of Uap56 In Pirna Mediated Transposon Silencing: A Dissertation, Fan Zhang Aug 2013

A Novel Role Of Uap56 In Pirna Mediated Transposon Silencing: A Dissertation, Fan Zhang

GSBS Dissertations and Theses

Transposon silencing is required to maintain genome stability. The non-coding piRNAs effectively suppress of transposon activity during germline development. In the Drosophila female germline, long precursors of piRNAs are transcribed from discrete heterochromatic clusters and then processed into primary piRNAs in the perinuclear nuage. However, the detailed mechanism of piRNA biogenesis, specifically how the nuclear and cytoplasmic processes are connected, is not well understood. The nuclear DEAD box protein UAP56 has been previously implicated in protein-coding gene transcript splicing and export. I have identified a novel function of UAP56 in piRNA biogenesis. In Drosophila egg chambers, UAP56 co-localizes with the ...


Transcript-Specific Cytoplasmic Degradation Of Yra1 Pre-Mrna Mediated By The Yeast Edc3 Protein: A Dissertation, Shuyun Dong Dec 2007

Transcript-Specific Cytoplasmic Degradation Of Yra1 Pre-Mrna Mediated By The Yeast Edc3 Protein: A Dissertation, Shuyun Dong

GSBS Dissertations and Theses

mRNA degradation is a fundamental process that controls both the level and the fidelity of gene expression. Using a combination of bioinformatic, genomic, genetic, and molecular biology approaches, we have shown that Edc3p, a yeast mRNA decay factor, controls the stability of the intron-containing YRA1 pre-mRNA. We found that Edc3p-mediated degradation of YRA1 pre-mRNA: 1) is a component of a negative feedback loop involved in the autoregulation of YRA1, 2) takes place in the cytoplasm, 3) is independent of translation, 4) occurs through a deadenylation-independent decapping and 5΄ to 3΄ exonucleotic decay mechanism, and 5) is controlled by specific cis ...