dc.contributor.advisor | Bennett, Karen L. | eng |
dc.contributor.author | Orsborn, April Marie, 1978- | eng |
dc.date.issued | 2006 | eng |
dc.date.submitted | 2006 Summer | eng |
dc.description | The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. | eng |
dc.description | Thesis (Ph. D.) University of Missouri-Columbia 2006. | eng |
dc.description | Vita. | eng |
dc.description.abstract | The Caenorhabditis elegans germline RNA helicases (GLHs) are constitutive components of P granules, non-membranous aggregates of protein and RNA that segregate with the nematode germline. The GLHs are critical for fertility. The novel MAP kinase, KGB-1, interacts with the GLH proteins, and the null kgb-1(um3) strain results in sterile worms at high temperatures; the germlines of these worms contain endomitotic replicating oocytes (EMO). We find that in kgb-1(um3) adults, while GLH-4 levels are similar to wild type, levels of GLH-1 are increased up to seven fold and the morphology of P granules is grossly affected. Binding of KGB-1 to GLH-1 requires a MAP kinase docking site. KGB-1 can phosphorylate GLH-1 using in vitro kinase assays, and GLH-1 is degraded by the proteasome in a KGB-1-dependent manner. In addition, KGB-1 physically associates with CSN-5 (COP9 signalosome subunit 5), another GLH binding partner. RNA interference (RNAi) of csn-5 results in sterile worms with under-proliferated germlines, mirroring the combined glh-1 and glh-4 RNAi phenotype. In contrast, elimination of csn-5 in the kgb-1(um3) background results in significantly more fertile worms than in non-injected kgb-1 worms. Based on these biochemical and genetic interactions, we propose KGB-1 and CSN-5 may oppositely regulate GLH-1, with KGB-1 degrading and CSN-5 protecting GLH-1. This cooperative system could maintain proper GLH-1 levels during normal germline development, as well as prevent excess GLH accumulation during the stressful conditions of high temperature and aging. | eng |
dc.description.bibref | Includes bibliographical references. | eng |
dc.identifier.merlin | b66330142 | eng |
dc.identifier.oclc | 309296428 | eng |
dc.identifier.uri | https://doi.org/10.32469/10355/4499 | eng |
dc.identifier.uri | https://hdl.handle.net/10355/4499 | |
dc.language | English | eng |
dc.publisher | University of Missouri--Columbia | eng |
dc.relation.ispartofcommunity | University of Missouri--Columbia. Graduate School. Theses and Dissertations | eng |
dc.rights | OpenAccess. | eng |
dc.subject.mesh | Cytoplasmic Granules | eng |
dc.subject.mesh | JNK Mitogen-Activated Protein Kinases -- metabolism | eng |
dc.subject.mesh | Germ Cells -- enzymology | eng |
dc.subject.mesh | Caenorhabditis elegans Proteins -- metabolism | eng |
dc.subject.mesh | DEAD-box RNA Helicases -- metabolism | eng |
dc.title | Analysis of interactions between the germline RNA helicases (GLHs) and their regulators KGB-1 and CSN-5 in Caenorhabditis elegans | eng |
dc.type | Thesis | eng |
thesis.degree.discipline | Microbiology (Medicine) (MU) | eng |
thesis.degree.grantor | University of Missouri--Columbia | eng |
thesis.degree.level | Doctoral | eng |
thesis.degree.name | Ph. D. | eng |