File Download
Supplementary

Conference Paper: Structure-function study of ubiquitin c-terminal hydrolase L1 (UCH-L1) by NMR spectroscopy - insights into UCH-L1 mutation's association with the risk of Parkinson's disease

TitleStructure-function study of ubiquitin c-terminal hydrolase L1 (UCH-L1) by NMR spectroscopy - insights into UCH-L1 mutation's association with the risk of Parkinson's disease
Authors
Issue Date2012
PublisherHKSN & BPHK.
Citation
The Joint Annual Scientific Meeting of Hong Kong Society of Neurosciences and the Biophysical Society of Hong Kong, Hong Kong, 14-15 June 2012. In Program Book, 2012, p. 79-80 How to Cite?
AbstractProtein ubiquitination and deubiquitination, play important roles in many aspects of cellular mechanisms. Its defective regulation results in diseases that range from developmental abnormalities to neurodegenerative diseases and cancer. Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) is a protein of 223 amino acids, which is highly abundant in brain, constituting up to 2% of total brain proteins. Although it was originally characterized as a deubiquitinating enzyme, recent studies indicate that it also functions as a ubiquitin ligase and a mono-Ub stabilizer. Down-regulation and extensive oxidative modifications of UCH-L1 have been observed in the brains of Alzheimer’s disease and Parkinson’s disease (PD) patients. Of importance, I93M and S18Y point mutations in the UCH-L1 gene have been reported to be linked to susceptibility to and protection from PD respectively. Hence, the structure of UCH-L1 and the effects of disease associated mutations on the structure and function are of considerable interest. Our circular dichroism studies suggest that the S18Y point mutation only slightly perturbs the structure while a significant decrease in the α-helical content is observed in the I93M mutant. We have determined the solution structure of S18Y and mapping its interaction with ubiquitin by chemical shift perturbation approach. The electrostatic surface potential analysis reveals that the interaction between ubiquitin and UCH-L1-S18Y is primarily electrostatic in nature, with negatively charged residues on the surface of UCH-L1-S18Y interacting with the positively charged residues on the basic face of ubiquitin. Although the active site and the L8 loop in UCH-L1-S18Y adopts conformations similar to that observed in the crystal structure of UCH-L1-WT, both the altered hydrogen bond network and surface charge distributions have demonstrated that the S18Y substitution could lead to profound structural changes. In particular, the difference in the dimeric interfaces of the wild-type and the S18Y mutant has shown that mutation can significantly affect the distribution of the surface-exposed residues involved in the dimeric interface. Such observed difference might weaken the stability of the UCH-L1 dimer and hence may explain the reduced dimerization-dependent ligase activity of UCH-L1-S18Y in comparison to UCH-L1-WT.
DescriptionPoster Presentation: P72
Persistent Identifierhttp://hdl.handle.net/10722/169358

 

DC FieldValueLanguage
dc.contributor.authorSze, KHen_US
dc.contributor.authorTse, HSen_US
dc.contributor.authorHu, HYen_US
dc.date.accessioned2012-10-18T08:51:03Z-
dc.date.available2012-10-18T08:51:03Z-
dc.date.issued2012en_US
dc.identifier.citationThe Joint Annual Scientific Meeting of Hong Kong Society of Neurosciences and the Biophysical Society of Hong Kong, Hong Kong, 14-15 June 2012. In Program Book, 2012, p. 79-80en_US
dc.identifier.urihttp://hdl.handle.net/10722/169358-
dc.descriptionPoster Presentation: P72-
dc.description.abstractProtein ubiquitination and deubiquitination, play important roles in many aspects of cellular mechanisms. Its defective regulation results in diseases that range from developmental abnormalities to neurodegenerative diseases and cancer. Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) is a protein of 223 amino acids, which is highly abundant in brain, constituting up to 2% of total brain proteins. Although it was originally characterized as a deubiquitinating enzyme, recent studies indicate that it also functions as a ubiquitin ligase and a mono-Ub stabilizer. Down-regulation and extensive oxidative modifications of UCH-L1 have been observed in the brains of Alzheimer’s disease and Parkinson’s disease (PD) patients. Of importance, I93M and S18Y point mutations in the UCH-L1 gene have been reported to be linked to susceptibility to and protection from PD respectively. Hence, the structure of UCH-L1 and the effects of disease associated mutations on the structure and function are of considerable interest. Our circular dichroism studies suggest that the S18Y point mutation only slightly perturbs the structure while a significant decrease in the α-helical content is observed in the I93M mutant. We have determined the solution structure of S18Y and mapping its interaction with ubiquitin by chemical shift perturbation approach. The electrostatic surface potential analysis reveals that the interaction between ubiquitin and UCH-L1-S18Y is primarily electrostatic in nature, with negatively charged residues on the surface of UCH-L1-S18Y interacting with the positively charged residues on the basic face of ubiquitin. Although the active site and the L8 loop in UCH-L1-S18Y adopts conformations similar to that observed in the crystal structure of UCH-L1-WT, both the altered hydrogen bond network and surface charge distributions have demonstrated that the S18Y substitution could lead to profound structural changes. In particular, the difference in the dimeric interfaces of the wild-type and the S18Y mutant has shown that mutation can significantly affect the distribution of the surface-exposed residues involved in the dimeric interface. Such observed difference might weaken the stability of the UCH-L1 dimer and hence may explain the reduced dimerization-dependent ligase activity of UCH-L1-S18Y in comparison to UCH-L1-WT.-
dc.languageengen_US
dc.publisherHKSN & BPHK.-
dc.relation.ispartofJoint Annual Scientific Meeting of Hong Kong Society of Neurosciences and the Biophysical Society of Hong Kong 2012 Program booken_US
dc.rightsCreative Commons: Attribution 3.0 Hong Kong License-
dc.titleStructure-function study of ubiquitin c-terminal hydrolase L1 (UCH-L1) by NMR spectroscopy - insights into UCH-L1 mutation's association with the risk of Parkinson's diseaseen_US
dc.typeConference_Paperen_US
dc.identifier.emailSze, KH: khsze@hku.hken_US
dc.identifier.authoritySze, KH=rp00785en_US
dc.description.naturepostprint-
dc.identifier.hkuros211865en_US
dc.identifier.spage79en_US
dc.identifier.epage80en_US
dc.publisher.placeHong Kong-

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats