| dc.contributor.author | Lewis, Stephen Murdock. | en_US |
| dc.date.accessioned | 2014-10-21T12:36:55Z | |
| dc.date.available | 2004 | |
| dc.date.issued | 2004 | en_US |
| dc.identifier.other | AAINQ94046 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/54661 | |
| dc.description | Membrane and protein cargo is moved among intracellular compartments by small, protein-coated lipid carriers known as transport vesicles. The formation and function of transport vesicles is controlled by several proteins, of which one is the small GTPase Arf. Arf function for vesicular transport is regulated by a cycle of GTP binding and GTP hydrolysis, which in turn is regulated by Arf guanine exchange factors (ArfGEFs) and Arf G&barbelow;TPase-a&barbelow;ctivating p&barbelow;roteins (ArfGAPs). In the budding yeast Saccharomyces cerevisiae, the ArfGAPs Gcs1 and Glo3 share essential overlapping function for retrograde vesicular transport from the cis-Golgi apparatus to the endoplasmic reticulum. | en_US |
| dc.description | I have addressed the role of ArfGAP function for retrograde transport by identifying proteins that, when present in increased abundance, can suppress the temperature-sensitive phenotype of gcs1-28 glo3Delta double-mutant cells. I have identified the novel ArfGAP Age1 as a suppressor of the effects of deficient Gcs1 and Glo3 ArfGAP function for retrograde transport. Moreover, a mutant allele of AGE1 lacking the amino-terminal coding sequences (age1-Delta164) is able to suppress gcs1-28 glo3Delta temperature sensitivity, even in low copy number. These data provide in vivo evidence that the Age1 ArfGAP can function for vesicular transport. I have also identified the SLY41 gene as a dosage suppressor of gcs1-28 g1o3Delta temperature sensitivity. Sly41 has been previously implicated in vesicular transport, and has homology to a small-ion transporter from spinach chloroplasts. Analysis of Sly41 suppression has led to the identification of a cell-wall defect in gcs1-28 g1o3Delta double-mutant cells. | en_US |
| dc.description | In this study, I have also characterized the contribution of the Gcs1 and Glo3 ArfGAPs to the retrograde-transport process at the molecular level. I have found that Glo3 associates with coatomer in vivo and is a component of COPI vesicles, whereas Gcs1 is not. Furthermore, a novel mutant version of Glo3 (Glo3-R59K) exerts a negative effect on cell growth and vesicular transport, even in the presence of the Gcs1 ArfGAP. These data indicate that Glo3 is the primary ArfGAP required for retrograde vesicular transport. Finally, I find that intact ArfGAP function is required for the generation of COPI vesicles. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 2004. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Biology, Molecular. | en_US |
| dc.subject | Biology, Cell. | en_US |
| dc.subject | Biology, Microbiology. | en_US |
| dc.subject | Health Sciences, Immunology. | en_US |
| dc.title | Multiple ArfGAPs regulate vesicular transport. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
