Return to search

Determining the role of protein regulators of hisactophilin on actin filament formation

Protein structure and functions are tightly regulated. Studying the integration of multiple
modifications in single systems is a novel approach. Hisactophilin protein from Dictyostelium
discoideum, is an actin binding protein that serves to induce formation of actin filaments and is
regulated by protonation and myristoylation. Utilizing hisactophilin as a model, I determined the
effect of pH and myristoyl-switching on actin binding and filament induction using fluorescence
spectroscopy, light scattering, and time-course electron microscopy. Results revealed the
accessible myristoyl group slows binding and the rate of actin polymerization compared to when
the group is sequestered. Hisactophilin induces pH-dependent actin aggregates before
reorganizing them into filaments and bundles. Hisactophilin mutants impact initial actin binding
and the kinetics of the aggregated state. I determined the cooperativity of myristoylation and
protonation as interdependent protein regulatory mechanisms, their impact on actin binding and
proposed a novel mechanism for actin polymerization as a result of these integrated regulators. / NSERC

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OGU.10214/5264
Date09 January 2013
CreatorsMcRorie, Paul Alexander
ContributorsDawson, John
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeThesis
Rightshttp://creativecommons.org/licenses/by/2.5/ca/

Page generated in 0.0019 seconds