Ubiquitin Carboxy-terminal Hydrolase L1 Gene Research Articles

Case-control study of the UCH-L1 S18Y variant in sporadic Parkinson’s disease in the Chinese population

The ubiquitin carboxy-terminal hydrolase L1 gene ( UCH-L1) has been implicated in the etiology of Parkinson’s disease (PD). In several previous studies, an S18Y (C54A) polymorphism in exon 3 of the UCH-L1 gene has been found to be protective against PD. We performed polymerase chain reaction–restriction fragment length polymorphism analysis for DNA samples from 408 Chinese patients with PD and 398 Chinese healthy controls. For the S18Y variant, there was no significant difference either in the individual allele or genotype frequencies between cases and control subjects. Possession of the S18Y variant did not alter the risk of developing PD (odds ratio: 0.827; 95% confidence interval = 0.596–1.147). There was no statistically significant difference in terms of age or sex distribution between the patients and controls ( p > 0.05). Overall, considering our present results together with those of our previous studies, we now have access to data from more than 1000 patients from different regions of China, supporting the conclusion that the S18Y polymorphism may not have a protective effect against PD in the Chinese population.

Backbone and side-chain 1H, 15N and 13C resonance assignments of S18Y mutant of ubiquitin carboxy-terminal hydrolase L1

Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), also known as PGP9.5, is a protein of 223 amino acids. Although it was originally characterized as a deubiquitinating enzyme, recent studies indicate that it also functions as a ubiquitin (Ub) ligase and a mono-Ub stabilizer. It is highly abundant in brain, constituting up to 2% of total brain proteins. Down-regulation and extensive oxidative modification of UCH-L1 have been observed in the brains of Alzheimer’s disease (AD) and Parkinson’s disease (PD) patients. Mutations in the UCH-L1 gene have been reported to be linked to Parkinson’s disease, in particular, the I93 M variant is associated with a higher susceptibility of PD in contrast to a higher protection against PD for the S18Y variant. Hence, the structure of UCH-L1 and the underlying effects of disease associated mutations on the structure and function of UCH-L1 are of considerable interest. Here, we report the NMR spectral assignments of the S18Y human UCH-L1 mutant with the aim to obtain better understanding about the risk of Parkinson’s disease against structural and dynamical changes induced by this mutation on UCH-L1.

Ubiquitin carboxy-terminal hydrolase L1 (UCHL1) S18Y polymorphism in Alzheimer's disease

Alzheimer's disease (AD) is characterized by protein aggregates, i.e. senile plaques and neurofibrillary tangles. The ubiquitin-proteasome system has been proposed a role in proteolytic removal of these protein aggregates. Ubiquitin carboxy-terminal hydrolase L1 (UCHL1) is a de-ubiquitinating enzyme with important functions in recycling of ubiquitin. The S18Y polymorphism of the UCHL1 gene confers protection against Parkinson's disease. In this study, the genotype and allele frequencies of the UCHL1 S18Y polymorphism were investigated in 452 AD patients and 234 control subjects, recruited from four memory clinics in Sweden. Using a binary logistic regression model including UCHL1 allele A and APOE ε4 allele positivity, age and sex as covariates with AD diagnosis as dependent variable, an adjusted OR of 0.82 ([95% CI 0.55-1.24], P = 0.35) was obtained for a positive UCHL1 allele A carrier status. The present study thus do not support a protective effect of the UCHL1 S18Y polymorphism against AD.

Target Genes of Neuron-Restrictive Silencer Factor Are Abnormally Up-Regulated in Human Myotilinopathy

Myotilinopathy is a subgroup of myofibrillar myopathies caused by mutations in the myotilin gene in which there is aggregation of abnormal cytoskeletal proteins and ubiquitin. We report here on the accumulation of neuron-related proteins such as ubiquitin carboxy-terminal hydrolase L1 (UCHL1), synaptosomal-associated protein 25, synaptophysin, and alpha-internexin in aberrant protein aggregates in myotilinopathy. We have determined that the neuron-restrictive silencer factor (NRSF)/RE1 silencing transcription factor (REST), a transcription factor expressed in non-neuronal tissues repressing the expression of several neuronal genes, is reduced in myotilinopathies. Moreover, NRSF transfection reduces UCHL1, synaptosomal-associated protein 25, synaptophysin, and alpha-internexin mRNA levels in DMS53 cells, whereas short interferring NRSF transfection increases UCHL1 and synaptophysin mRNA levels in U87-MG cells. Chromatin immunoprecipitation assays have shown that NRSF interacts with the UCHL1 promoter in U87-MG and HeLa cells. In silico analysis of the UCHL1 gene promoter sequence using the MatInspector software has predicted three potential neuron-restrictive silencer elements (NRSEs): NRSE1 located in the complementary DNA chain and NRSE2 and NRSE3 in intron 1, in the coding and complementary chains, respectively. Together, these findings show, for the first time, abnormal regulation of NRSF/REST as a mechanism associated with the aberrant expression of selected neuron-related proteins, which in turn accumulate in abnormal protein aggregates, in myotilinopathy.

Genetic association between Ubiquitin Carboxy-terminal Hydrolase-L1 gene S18Y polymorphism and sporadic Alzheimer's disease in a Chinese Han population

Increasing evidence indicates that the dysfunction of ubiquitin–proteasome system (UPS) is associated with Alzheimer's disease (AD). In the ubiquitin–proteasome pathway, Ubiquitin Carboxy-terminal Hydrolase-L1 (UCH-L1) plays an important role for the cellular clearance of abnormal proteins. Since a substitution of serine by tyrosine at codon 18, exon 3 (S18Y polymorphism) of the UCH-L1 gene exhibits a protective effect against the development of degenerative disease such as sporadic Parkinson's disease (PD) in several different ethnic groups, we hypothesized that UCH-L1 gene S18Y polymorphism may have that same effect on the pathologic process of AD. We examined UCH-L1 S18Y polymorphism genotypes of 116 sporadic AD patients and 123 healthy subjects in Chinese Han population using PCR-restriction fragment length polymorphism (RFLP) analysis. The allele and genotype data as well as data after stratification by age of onset failed to demonstrate any association between AD and S18Y polymorphism. However, after stratification by gender, female AD patients showed significantly less frequencies of Y allele and YY genotype in S18Y polymorphism than female controls ( P = 0.003 and P = 0.015 respectively). We conclude that Y allele and YY genotype of S18Y in the UCH-L1 gene may have a protective effect against sporadic AD in female subjects, probably due to altering the function of UCH-L1 and the interactions among different risk factors.

Mutation analysis and association studies of the ubiquitin carboxy-terminal hydrolase L1 gene in Huntington's disease

Huntington's disease (HD) is attributed to a triplet CAG repeat mutation, and about 70% of the variance in age-at-onset can be explained by the size of the repeat expansion. Among potential candidates as modifier genes, we investigated the role of ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) gene. We examined the association of HD with the I93M mutation and S18Y polymorphism in 138 HD patients and 136 control subjects, but we did not identify the I93M mutation. The S18Y polymorphism was present in 17% of HD patients. Of the variance in the age-at-onset that was not accounted for by the CAG repeat, 13% could be attributed to S18Y polymorphism. We sequenced the entire coding region of the UCH-L1 gene in seven HD patients with unexplained older or younger onset age. The S18Y polymorphism was found in three out of the four patients presenting with a later age-at-onset. We conclude that the UCH-L1 gene may be a genetic factor that influences the variability in age-at-onset of HD.

Lack of association between ubiquitin carboxy-terminal hydrolase L1 gene polymorphism and PD.

In 1998, an IL93Met mutation in the ubiquitin carboxy-terminal hydrolase L1 ( UCH-L1 ) gene was identified in a German family affected by PD.1 Recently, others2-4⇓⇓ found that the S18Y polymorphism in exon 3 of UCH-L1 is associated with a low risk of PD. To verify these interesting results, we decided to design a case-control study on the S18Y polymorphism of the UCH-L1 gene using sporadic PD cases. In the meantime, as we were analyzing our samples, a case-control study5 on 142 patients with PD and 142 age- and sex-matched control subjects did not confirm the protective effect found by Maraganore et al.2 In view of these conflicting findings, we reasoned that our contribution may have some weight in defining the role of the UCH-L1 gene in PD. Blood was collected from 169 patients with sporadic PD and 165 control subjects. Patients and control subjects were not matched for age and sex. Patients with PD were consecutively selected starting from January 1999 until September 2000 from among …

The ubiquitin carboxy-terminal hydrolase-L1 gene S18Y polymorphism does not confer protection against idiopathic Parkinson's disease

The ubiquitin carboxy-terminal hydrolase L1 gene (UCH-L1) has been implicated in the aetiology of Parkinson's disease (PD). A rare Ile93Met mutation in UCH-L1 in a German PD sib-pair has been reported. Recently, a S18Y (C54A) polymorphism in exon 3 of UCH-L1 was found to be under-represented in PD patients compared to controls. To test the reproducibility of this negative association, we conducted an allele-association study of the S18Y polymorphism in an Australian case-control sample consisting of 142 PD cases and 142 closely matched control subjects. Genotypes were determined using polymerase chain reaction and RsaI restriction enzyme assay. Analysis revealed no significant difference between PD patients and controls for genotype or allele frequencies of the S18Y polymorphism. The frequency of the S18Y allele in Australian subjects is similar to that reported elsewhere. This study suggests that the S18Y polymorphism in UCH-L1 does not influence the risk for developing PD.

Failure to find mutations in ubiquitin carboxy-terminal hydrolase L1 gene in familial Parkinson's disease.

Recently, a missense mutation (Ile93Met) of exon 4 in the ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) gene was identified in a German family with autosomal dominant Parkinson's disease (ADPD). To determine whether this mutation is responsible for familial Parkinson's disease (PD), we sequenced the entire coding region of UCH-L1 gene in nine families with ADPD. No mutations in this gene were found in any of the families studied. We conclude that the Ile93Met mutation in UCH-L1 gene is a very rare cause of familial PD.

Mutation analysis and association studies of the UCHL1 gene in German Parkinson's disease patients.

Recently, an Ile93Met substitution has been identified in the ubiquitin carboxy-terminal hydrolase L1 (UCHL1) gene in a single German PD family with autosomal dominant inheritance. To determine whether mutations in the UCHL1 gene are causative for Parkinson's disease (PD) a detailed mutation analysis was performed in a large sample of German sporadic and familial PD patients. We found no disease-causing mutation in the coding region of the UCHL1 gene. Direct sequencing revealed six intronic polymorphisms in the UCHL1 gene. Analysis of an S18Y polymorphism in exon 3 of the UCHL1 gene in sporadic PD patients and controls showed carriers of allele 2 (tyrosine) significantly less frequent in patients with a reduced risk of 0.57 (CI = 0.36-0.88; p = 0.012, p(c) = 0.047, chi2 = 6.31). Our study shows that sequence variations in the coding region of UCHL1 are a rare event. A protective effect of a certain UCHL1 variant in the pathogenesis of sporadic PD is suggested, underlining the relevance of UCHL1 in neurodegeneration.

Case-control study of the ubiquitin carboxy-terminal hydrolase L1 gene in Parkinson's disease.

We investigated the association of PD with a recently reported I93M mutation of the ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) gene, and with a new and common polymorphic variant S18Y of the same gene. We did not identify the I93M mutation in any of 139 unrelated PD cases or 113 controls. However, S18Y polymorphism carriers had significantly lower risk of PD (odds ratio = 0.53; p = 0.03), and the risk reduction was greater for younger onset cases.