Skip to main content
Duke University Libraries
DukeSpace Scholarship by Duke Authors
  • Login
  • Ask
  • Menu
  • Login
  • Ask a Librarian
  • Search & Find
  • Using the Library
  • Research Support
  • Course Support
  • Libraries
  • About
View Item 
  •   DukeSpace
  • Theses and Dissertations
  • Duke Dissertations
  • View Item
  •   DukeSpace
  • Theses and Dissertations
  • Duke Dissertations
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Regulation of CaMKKβ Dependent Signaling Pathways

Thumbnail
View / Download
3.3 Mb
Date
2011
Author
Green, Michelle Frances
Advisor
Means, Anthony R
Repository Usage Stats
368
views
1,103
downloads
Abstract

Ca<super>2+</super>/Calmodulin-dependent protein kinase kinase &beta;(CaMKK&beta;) is a serine/threonine directed kinase which is activated following increases in intracellular Ca<super>2+</super>. CaMKK&beta; activates Ca<super>2+</super>/Calmodulin-dependent protein kinase I (CaMKI), Ca<super>2+</super>/Calmodulin-dependent protein kinase IV (CaMKIV), and the AMP-dependent protein kinase (AMPK) in a number of physiological pathways including learning and memory formation, neuronal differentiation, and regulation of energy balance. The purpose of the work presented in this dissertation is to better understand the regulation of CaMKK&beta; activity and specificity in CaMKK&beta;-dependent signaling cascades. First, the CaMKK&beta;-AMPK signaling complex is examined using biochemical assays. In both brain and cell lysates CaMKK&beta; and AMPK form a stable complex which can be examined by co-immunoprecipitation. This complex lacks the AMPK&gamma; subunit and is not allosterically activated by adenosine 5'-monophohphate (AMP) binding. Using a series of CaMKK&beta; and AMPK mutants it was determined that the kinase domains of CaMKK&beta; and AMPK are necessary for their interaction and CaMKK&beta; must be active and bound to adenosine 5'-triphosphate (ATP) to form a complex with AMPK. However, CaMKK&beta; need not be active or bound to ATP to bind CaMKIV. This illustrates that the CaMKK&beta;-AMPK signaling complex differs from the CaMKK&beta;-CaMKIV signaling complex. These observations indicate that the CaMKK&beta;-AMPK signaling complex could be specifically targeted without effecting CaMKK&beta;-CaMKIV signaling.

Second, the regulation of CaMKK&beta; by multi-site phosphorylation is examined. Three phosphorylation sites in the N-terminus of CaMKK&beta; were identified by mass spectrometry which regulates its Ca<super>2+</super>/CaM-independent autonomous activity. The kinases responsible for these phosphorylations are identified as CDK5 and GSK3. These phosphorylation events are sequential with CDK5 priming for subsequent GSK3 phosphorylation. In addition to regulation of autonomous activity, phosphorylation of CaMKK&beta; regulates its half-life as determined in a radioactive pulse-chase assay. Examination of CaMKK&beta; in a cerebellar granule neuron model system demonstrates that CaMKK&beta; levels correlate with CDK5 activity and are regulated developmentally. In addition, appropriate phosphorylation of CaMKK&beta; is critical for its role in neurite development. These results reveal a novel regulatory mechanism for CaMKK&beta;-dependent signaling cascades.

Overall the work presented in this dissertation illustrates additional levels of regulation of CaMKK&beta;-dependent signaling pathways. In the future, these novel methods of CaMKK&beta; regulation will need to be considered when studying CaMKK&beta;-dependent signaling pathways.

Type
Dissertation
Department
Pharmacology
Subject
Molecular Biology
Pharmacology
Biochemistry
Calmodulin
Cell Signaling
Kinases
Permalink
https://hdl.handle.net/10161/5701
Citation
Green, Michelle Frances (2011). Regulation of CaMKK&beta; Dependent Signaling Pathways. Dissertation, Duke University. Retrieved from https://hdl.handle.net/10161/5701.
Collections
  • Duke Dissertations
More Info
Show full item record
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.

Rights for Collection: Duke Dissertations


Works are deposited here by their authors, and represent their research and opinions, not that of Duke University. Some materials and descriptions may include offensive content. More info

Make Your Work Available Here

How to Deposit

Browse

All of DukeSpaceCommunities & CollectionsAuthorsTitlesTypesBy Issue DateDepartmentsAffiliations of Duke Author(s)SubjectsBy Submit DateThis CollectionAuthorsTitlesTypesBy Issue DateDepartmentsAffiliations of Duke Author(s)SubjectsBy Submit Date

My Account

LoginRegister

Statistics

View Usage Statistics
Duke University Libraries

Contact Us

411 Chapel Drive
Durham, NC 27708
(919) 660-5870
Perkins Library Service Desk

Digital Repositories at Duke

  • Report a problem with the repositories
  • About digital repositories at Duke
  • Accessibility Policy
  • Deaccession and DMCA Takedown Policy

TwitterFacebookYouTubeFlickrInstagramBlogs

Sign Up for Our Newsletter
  • Re-use & Attribution / Privacy
  • Harmful Language Statement
  • Support the Libraries
Duke University