Abstract
dc:description.abstractThe Wingless (Wnt) signaling pathway is one of the critical developmental pathways for control of cell differentiation, proliferation, and cell growth. The DEP domain, located on the C-terminus of Dishevelled (Dvl), plays a role in cytoplasm-membrane association, which branches the canonical and non-canonical Wnt signaling pathway within the cell. It has been suggested that the DEP domain requires the recruitment of ionic lipids, such as phosphatidic acid, to regulate its localization to the plasma membrane and association to the frizzle receptor. However, the physical mechanism for DEP association to the plasma membrane is still unknown. We show that mDvl2-DEP interacts with phosphatidic acid at a distinct patch on the surface formed by a positively charged surface area by NMR spectroscopy. The binding of this interaction was also found at physiologically relevant concentration using fluorescence spectroscopy. We also determined that the interaction is pH-dependent and regulated through a 'histidine switch' mechanism at His464 and His465 where there is increased association of mDvl2-DEP to the plasma membrane at higher pH values (7.5). This association is based on tertiary structure conformational changes with rearrangement of the loop regions by a change in local pH, not its interaction with phosphatidic acid. Overall, our work will contribute to elucidate how cells regulate their developmental pathways through localized molecular interactions.
Degree
thesis:*- Name thesis:degree_name
- Master of Science
- Level thesis:degree_level
- masters
- Discipline thesis:degree_discipline
- Biology
- Department dc:contributor.department
- Biology
- Grantor dc:publisher
- Virginia Tech
- Year dc:date.issued
- 2010
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Lucas, Andrew Thomas
- Chairs dc:contributor.committeechair
-
- Finkielstein, Carla V.
- Capelluto, Daniel G. S.
- Committee member dc:contributor.committeemember
-
- Bevan, David R.
Subjects
dc:subject × 4Rights
dc:rights- Statement dc:rights
-
- In Copyright
- Licence dc:rights.uri
- Language dc:language.iso
- en_US
Identifiers
dc:identifier.*- Dc Identifier Other
- etd-04302010-134259
- OAI identifier oai:identifier
- oai:vtechworks.lib.vt.edu:10919/76974