Molecular Biology Commons^™

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 …

Exploring The Role Of Rna Polymerase Iii Complex Assembly On Ribosomal Dna Silencing In Saccharomyces Cerevisiae, Kyle Thomas Kern

LSU Doctoral Dissertations

The yeast rDNA region is host to a number of transcriptional regulatory elements, which work in conjunction to generate essential RNA subunits of ribosomes, as well as protecting the region from DNA damage. The role of RNA polymerase III complex binding at the 5S gene on rDNA silencing in the NTS2 region was investigated, both by use of a TY1:MET15 reporter insert and a MET15 gene integration at an endogenous SphI site. It was discovered that Pol III complexes do have an effect on reporter expression in the NTS2 region, though the specific effect was different based on the method …

Influence Of The Pre-Initiation Complex On Mediator Recruitment In Saccharomyces Cerevisiae, Elisabeth Rose Knoll

Legacy Theses & Dissertations (2009 - 2024)

The Mediator complex plays a central, highly conserved role in eukaryotic transcription by RNA Polymerase II (Pol II) by stimulating the cooperative assembly of a pre-initiation complex (PIC) and recruitment of Pol II for gene activation. Mediator recruitment has generally been ascribed to sequence-specific activators engaging subunits from the tail module which in turn function to recruit the middle and head for complete assembly at the UAS. Mediator subunits of the middle and head then bridge the enhancer to connect with the PIC at the core promoter. It is reported that Mediator recruitment at the UAS preferentially occurs at SAGA-dependent, …

Dna Polymerase Zeta-Dependent Mutagenesis: Molecular Specificity, Extent Of Error-Prone Synthesis, And The Role Of Dntp Pools, Olga V. Kochenova

Theses & Dissertations

Despite multiple DNA repair pathways, DNA lesions can escape repair and compromise normal chromosomal replication, leading to genome instability. Cells utilize specialized low-fidelity Translesion Synthesis (TLS) DNA polymerases to bypass lesions and rescue arrested replication forks. TLS is a highly conserved two-step process that involves insertion of a nucleotide opposite a lesion and extension of the resulting aberrant primer terminus. The first step can be performed by both replicative and TLS DNA polymerases and, because of non-instructive DNA lesions, often results in a nucleotide misincorporation. The second step is almost exclusively catalyzed by DNA polymerase ζ …

Prolonged Glucose Deprivation Sensitizes Snf1 To Negative Regulation By Pka To Delay Entry Into Quiescence, Leah Bernadette Doughty

Theses and Dissertations

AMPK, the fuel gauge of the cell, and its upstream kinase, LKB1, have been implicated in cancer prevention and stress response associated with energy exhaustion. In the yeast Saccharomyces cerevisiae, Snf1 is the ortholog of mammalian AMPK. In S. cerevisiae, Snf1 is activated by phosphorylation of its T–loop at Thr210, primarily by its upstream kinase Sak1, in absence of the preferred carbon source, glucose, or during some other stress responses. Cyclic AMP–dependent protein kinase A, PKA, is involved in nutrient signaling largely antagonistically to Snf1. Using yeast strains of the Sigma 1278b genetic background, which have a high basal level …

Investigating The Roles Of Ndj1 And Tid1 In Crossover Assurance In Saccharomyces Cerevisiae, Rianna Knowles

Master's Theses

Meiosis is the specialized process of cell division utilized during gametogenesis in all sexually reproducing eukaryotes, which consists of one round of DNA replication followed by two rounds of chromosome segregation and results in four haploid cells. Crossovers between homologous chromosomes promote proper alignment and segregation of chromosomes during meiosis.

Crossover interference is a genetic phenomenon in which crossovers are non-randomly placed along chromosomes. Crossover assurance ensures that every homologous chromosome pair obtains at least one crossover during Prophase I. Crossovers physically connect homologous pairs, allowing spindle fibers to attach and separate homologs properly. However, some organisms have shown an …