2008 — 2016 |
Gasch, Audrey P |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Functional Genomics of Stress Defense in Yeast @ University of Wisconsin-Madison
DESCRIPTION (provided by applicant): All organisms must protect their internal system from cellular stress. Whether stress arises from external toxins or mutation and disease, cells must sensitively monitor stress signals and mount the appropriate responses to maintain internal homeostasis. Despite the importance of stress defense, much remains unknown about the mechanisms eukaryotes use to survive stressful situations. Functional genomics has uncovered functions for many genes in various genomes, largely by characterizing gene function under standard conditions. However, a substantial fraction of genes remains uncharacterized, and many of these are likely to be involved in stress defense and thus have not been uncovered through traditional studies. This proposal will use high-throughput functional genomics, genomic expression analysis, computational biology, and techniques in genetics and biochemistry to identify and characterize genes involved in stress defense in yeast. Aim 1 will exploit two new phenotypes related to stress defense to uncover novel genes involved in eukaryotic stress survival. The first is a phenomenon known as `acquired stress resistance', in which cells exposed to a small dose of one stress become resistant to an otherwise lethal dose of a different stress. The second is a phenomenon in which cells retain a `memory'of stress resistance that persists for many generations after mild-stress treatment, even after the mild stress has been removed. We will use these phenotypes in high-throughput selections to identify yeast deletion mutants that cannot acquire or retain resistance to severe stress after mild-stress treatment. Identified genes, as well as known regulators of acquired stress resistance, will be characterized to define their precise roles in these phenomena. Cells respond to stress with a multi-facetted response. This response, including reorganization of genomic expression, is coordinated by a complex signaling network that responds to stress. Aim 2 will elucidate the intricate stress-activated signaling network in yeast that orchestrates genomic expression responses to stress. Regulators of stress-dependent genes will be identified by screening the yeast-deletion library for mutants unable to induce expression upon stress treatments. Identified regulators and various known network components will be organized into a putative signaling network, using numerous computational approaches. This network will be subsequently dissected and refined based on genomic, genetic, and biochemical studies. These experiments will help to elucidate the complex stress-activated signaling network in yeast, which serves as an excellent model for such networks in humans and other organisms, while developing computational approaches that are likely to advance this area of biology. As many of these responses are conserved in humans, these results will foster stress minimization and disease prevention in human medicine. Project Relevance: Many stress-defense mechanisms used by yeast are conserved in humans, and therefore the results of this proposal will provide a strong foundation for understanding, and eventually modulating, stress resistance for human health. These results will have broad application, from minimizing debilitating side effects of chemotherapy, to reducing trauma inflicted by invasive surgery, heart attacks and strokes, to preventing cancer. Furthermore, understanding how yeast sense and respond to stress is an excellent model for how human cells respond to analogous cellular stresses.
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0.954 |
2015 — 2020 |
Gasch, Audrey P |
T32Activity Code Description: To enable institutions to make National Research Service Awards to individuals selected by them for predoctoral and postdoctoral research training in specified shortage areas. |
Predoctoral Training Program in Genetics @ University of Wisconsin-Madison
DESCRIPTION (provided by applicant): The proposed Research Training Program will train predoctoral students broadly in the discipline of genetics at the University of Wisconsin - Madison. Students admitted to the Genetics graduate program at Wisconsin will be supported for two years of graduate studies: the first year and a subsequent year after completing all required coursework and qualifying examinations. The Genetics graduate program presently consists of 79 faculty representing 20 different departments in the biological sciences and 53 students studying with 28 different faculty trainers. The collective research interests of program faculty and students encompass virtually the entire breadth and depth of contemporary genetics. Trainees are selected based on prior academic achievements, research experience, and personal interviews conducted before acceptance into the program. Accepted students identify Genetics as their primary academic pursuit and choose thesis advisors based on their individual research interests The Genetics doctoral program is a campus-wide training program administered by the Laboratory of Genetics, which is housed in a modern state-of-the-art research facility. Supported students complete a rigorous academic program consisting of both formal coursework and individualized mentoring in genetics. Formal coursework includes a core curriculum of required genetics courses, specialized electives identified by students together with their Thesis Advisory Committee, a course in the responsible conduct of research (RCR), and continuing exposure to RCR-related issues throughout the graduate career. Students gain teaching and communication experience by serving for one semester as a Teaching Assistant for an undergraduate Genetics course and by presenting their research in formal settings before faculty and students of the program. Student performance is evaluated by a two-part qualifying examination that tests understanding of broad genetic principles and an ability to propose, execute, and defend a thesis research project. Each student's progress is monitored annually by a Thesis Advisory Committee. The Genetics Training Grant develops young investigators as independent scientists by providing a rigorous and broad education in the science of genetics. Our graduates bring the methods and logic of genetic analysis to bear on contemporary research problems. Our long range goal is to educate new generations of professional geneticists who will advance the biological research sciences using genetic approaches and methodologies.
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0.954 |
2018 — 2021 |
Gasch, Audrey P |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Molecular Approaches to Sensitizing Eukaryotic Cells to Aneuploidy @ University of Wisconsin-Madison
Abstract Aneuploidy, the state in which cells carry an incorrect number of chromosomes, is a hallmark of human cancers. Over 85% of cancers are aneuploid, and higher rates of aneuploidy are often associated with poor patient prognosis. Aneuploid tumors can display heterogeneous karyotypes, which underlie heterogeneity in cellular phenotypes. This presents a specific challenge in treating aneuploid tumors, because they can rapidly evolve mechanisms to evade treatment. Given the high incidence of aneuploidy in diverse cancer types, an attractive strategy would be to selectively sensitize cells to the aneuploid state itself, especially in combination with chemotherapy drugs. This has been challenging, in large part because it remains unclear how aneuploid cancer cells can tolerate extra DNA content in the first place. We have taken a novel perspective to this challenge, by studying wild strains of budding yeast Saccharomyces cerevisiae that are naturally tolerant to extra chromosomes. Yeast is a powerful model for dissecting cellular biology, because many of the mechanisms and defense strategies are conserved in humans. By comparing aneuploidy-tolerant wild strains to a well-studied laboratory strain that is unusually sensitive to aneuploidy, we discovered a single gene that, when deleted, produces little to no phenotype in euploid strains, but renders cells very sensitive to extra chromosomes. Thus, we can sensitize cells to aneuploidy without producing major phenotypes in the normal euploid cells. The gene ? Ssd1 ? has been implicated in mRNA localization, translational control, and chromosome maintenance among other things, but the mechanisms remain unclear. We believe that the process of aneuploidy tolerance is conserved between yeast and humans. The human ortholog of Ssd1, hDis3L2, shares several features with Ssd1, including links to translational regulation, P-body localization, and proper chromosome segregation. The goal of this proposal is two fold: 1) to identify the mechanism through which SSD1 deletion sensitizes yeast to aneuploidy and 2) to use this information to test if knockdown of orthologous functions sensitizes cancer cell lines to aneuploidy, with and without chemotherapy treatment. Aim 1 will use genomics, proteomics, single-molecule RNA fluorescence in situ hybridization (FISH), and singe, live-cell imaging to test the role of Ssd1 in aneuploidy tolerance. Aim 2 will leverage these insights to test if orthologous mechanisms, including knockdown of the human ortholog hDis3L2, can sensitize breast and colon cancer cell lines to aneuploidy, with and without paclitaxel treatment. This aim will use a powerful system to produce isogenic sets of euploid and aneuploid human cells, enabling sensitive dissection of phenotypes that are specific to the aneuploid state. Results of this work will expand our understanding of the function of Ssd1/hDis3L2 and could pave the way to new therapeutic approaches to target aneuploid cells.
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0.954 |