Protein-protein interactions that mediate the role of AAA-ATPase p97/VCP/Cdc48 in protein aggregation and degradation
Chia, Wei Sheng
Date of Issue2013
School of Biological Sciences
p97/VCP is a multifunctional AAA-ATPase that is directed into many different cellular processes by adaptor proteins that bind to it. With the use of SPR biosensor technology, we demonstrated the role of ATP binding to the D1 ATPase domain in p97/VCP in regulating adaptor protein competition between Ufd1/Npl4 and p47, two major adaptor proteins of p97/VCP that direct it to this AAA-ATPase to different corecomplexes for executing different cellular functions. A novel p97/VCP adaptor protein, AIRAPL was also characterized for its binding to p97/VCP via AIRAPL's VIM domain and to substrates such as K48-tetraubiquitin chains via its tandem double-sided UIMs. We speculate possible roles of AIRAPL in regulating ubiquitin chain lengths and consequently ubiquitin-dependent processes by affecting deubiquitinase activity. In an attempt to develop a system for studying metabolic fluxes in correlation with p97/VCP functions and activities in the cell, we validated a new group of chemical ATP sensors known as cationic polythiophene polymers. Using these sensors, a real-time ATPase assay was developed and authenticated.