Hsp104 and Potentiated Variants Can Operate as Distinct Nonprocessive Translocases. Biophys J 2019 May 21;116(10):1856-1872
Date
04/28/2019Pubmed ID
31027887Pubmed Central ID
PMC6531783DOI
10.1016/j.bpj.2019.03.035Scopus ID
2-s2.0-85064567361 (requires institutional sign-in at Scopus site) 12 CitationsAbstract
Heat shock protein (Hsp) 104 is a hexameric ATPases associated with diverse cellular activities motor protein that enables cells to survive extreme stress. Hsp104 couples the energy of ATP binding and hydrolysis to solubilize proteins trapped in aggregated structures. The mechanism by which Hsp104 disaggregates proteins is not completely understood but may require Hsp104 to partially or completely translocate polypeptides across its central channel. Here, we apply transient state, single turnover kinetics to investigate the ATP-dependent translocation of soluble polypeptides by Hsp104 and Hsp104A503S, a potentiated variant developed to resolve misfolded conformers implicated in neurodegenerative disease. We establish that Hsp104 and Hsp104A503S can operate as nonprocessive translocases for soluble substrates, indicating a "partial threading" model of translocation. Remarkably, Hsp104A503S exhibits altered coupling of ATP binding to translocation and decelerated dissociation from polypeptide substrate compared to Hsp104. This altered coupling and prolonged substrate interaction likely increases entropic pulling forces, thereby enabling more effective aggregate dissolution by Hsp104A503S.
Author List
Durie CL, Lin J, Scull NW, Mack KL, Jackrel ME, Sweeny EA, Castellano LM, Shorter J, Lucius ALAuthor
Elizabeth Sweeny PhD Assistant Professor in the Biochemistry department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Adenosine TriphosphateAmino Acid Sequence
Heat-Shock Proteins
Hydrolysis
Kinetics
Mutant Proteins
Peptides
Protein Aggregates
Protein Binding
Protein Conformation
Protein Folding
Saccharomyces cerevisiae Proteins
Structure-Activity Relationship
