The effect of Parkinson's-disease-associated mutations on the deubiquitinating enzyme UCH-L1.
The neuronal ubiquitin C-terminal hydrolase (UCH) UCH-L1 has been linked to Parkinson's disease (PD) and other neurodegenerative diseases. Here, we present a study on the structure, stability, unfolding, and dynamics of wild-type and mutant UCH-L1. Fluorescence, far-UV CD, and NMR measurements were used to establish that the unfolding of UCH-L1 is three-state under equilibrium conditions and that an intermediate is populated. S18Y and I93M mutants, which are associated with a decreased risk or an increased risk of PD, respectively, are less stable than wild type. However, while there is minimal structural perturbation in the S18Y mutant, the I93M mutation is more disruptive. In particular, the NMR data suggest that there are local rearrangements around the site of the mutation, which we propose results in the exposure of hydrophobic surface area. This may have two consequences: an increased tendency towards, firstly, aggregation in vivo, and, secondly, aberrant interactions with tubulin and the chaperone-mediated autophagy machinery as observed by other groups, both of which may be involved in neurodegenerative processes.
Department of Chemistry, University of Cambridge, Cambridge, UK.
Fredrik I
FI
Andersson
Elizabeth F
EF
Werrell
Lindsay
L
McMorran
William J K
WJ
Crone
Chittarnajan
C
Das
Shang-Te Danny
ST
Hsu
Sophie E
SE
Jackson
D041961:Deuterium Exchange Measurement / Q000379:methods; D004795:Enzyme Stability; D005838:Genotype; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009154:Mutation; D010300:Parkinson Disease / Q000201:enzymology / Q000235:genetics*; D017354:Point Mutation; D011489:Protein Denaturation / Q000187:drug effects; D013816:Thermodynamics; D043222:Ubiquitin Thiolesterase / Q000235:genetics*
C482860:UCHL1 protein, human; D043222:Ubiquitin Thiolesterase