Abstract
dc:description.abstractAdaptor proteins, like Tollip and Tom1, facilitate cellular cargo sorting through their ubiquitin-binding domains. Tollip and Tom1 bind to each other through their TBD and GAT domains, respectively, whereas Tollip interacts with phosphatidylinositol-3-phosphate (PtdIns(3)P)-containing endosomal membranes. Tom1 and Tollip interaction and association with endosomes is proposed to be involved in the lysosomal degradation of polyubiquitinated cargo. Through cellular, biochemical, and biophysical techniques, we have further characterized the association of Tom1 with Tollip. Mutations in the binding interface of the Tom1 GAT and Tollip TBD complex leads to a subcellular mis-localization of both proteins, indicating that Tom1 may serve to direct Tollip to specific cellular pathways. It was determined that Tom1 inhibits the binding of Tollip to PtdIns(3)P and inhibition was reversed when mutations in the binding interface of the Tom1 GAT and Tollip TBD were present. Furthermore, it was established that, upon the binding of Tollip TBD to Tom1 GAT, ubiquitin is inhibited from binding to Tom1 GAT. It was also demonstrated that Tom1 GAT, but not Tollip TBD, can weakly bind to PtdIns(3)P. Consequently, we propose that association of Tom1 may serve to direct Tollip for involvement in specific cell signaling pathways. Gaining insight into the function of Tom1 and Tollip may lead to their use as therapeutic targets for increasing the efficiency of cargo trafficking and also for patients recovering from various cardiac injuries.
Degree
thesis:*- Name thesis:degree_name
- Master of Science
- Level thesis:degree_level
- masters
- Discipline thesis:degree_discipline
- Biological Sciences
- Department dc:contributor.department
- Biological Sciences
- Grantor dc:publisher
- Virginia Tech
- Year dc:date.issued
- 2015
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Brannon, Mary Katherine
- Chair dc:contributor.committeechair
-
- Capelluto, Daniel G. S.
- Committee members dc:contributor.committeemember
-
- Kelly, Deborah F.
- Bevan, David R.
- Sible, Jill C.
Subjects
dc:subject × 8Rights
dc:rights- Statement dc:rights
-
- In Copyright
- Licence dc:rights.uri
Identifiers
dc:identifier.*- Dc Identifier Other
- vt_gsexam:5305
- OAI identifier oai:identifier
- oai:vtechworks.lib.vt.edu:10919/73814