Dataset Information

Site-specific differences in proteasome-dependent degradation of monoubiquitinated ?-synuclein.

ABSTRACT: The formation of toxic aggregates composed largely of the protein ?-synuclein are a hallmark of Parkinson's disease. Evidence from both early-onset forms of the disease in humans and animal models has shown that the progression of the disease is correlated with the expression levels of ?-synuclein, suggesting that cellular mechanisms that degrade excess ?-synuclein are key. We and others have shown that monoubiquitinated ?-synuclein can be degraded by the 26S proteasome; however, the contributions of each of the nine known individual monoubiquitination sites were unknown. Herein, we determined the consequences of each of the modification sites using homogenous, semisynthetic proteins in combination with an in vitro proteasome turnover assay. The data suggest that the site-specific effects of monoubiquitination support different levels of ?-synuclein degradation.

SUBMITTER: Abeywardana T

PROVIDER: S-EPMC3855323 | biostudies-literature | 2013 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Site-specific differences in proteasome-dependent degradation of monoubiquitinated α-synuclein.

Abeywardana Tharindumala T Lin Yu Hsuan YH Rott Ruth R Engelender Simone S Pratt Matthew R MR

Chemistry & biology 20131001 10

The formation of toxic aggregates composed largely of the protein α-synuclein are a hallmark of Parkinson's disease. Evidence from both early-onset forms of the disease in humans and animal models has shown that the progression of the disease is correlated with the expression levels of α-synuclein, suggesting that cellular mechanisms that degrade excess α-synuclein are key. We and others have shown that monoubiquitinated α-synuclein can be degraded by the 26S proteasome; however, the contributio ...[more]

PMID: 24210006

Similar Datasets

Project description:Although the neurobiological basis of autism spectrum disorder (ASD) is not fully understood, recent studies have indicated the potential role of GABAA receptors in the pathophysiology of ASD. GABAA receptors play a crucial role in various neurodevelopmental processes and adult neuroplasticity. However, the mechanism(s) of regulation of GABAA receptors in ASD remains poorly understood.Postmortem middle frontal gyrus tissues (13 ASD and 13 control subjects) were used. In vitro studies were performed in primary cortical neurons at days in vitro (DIV) 14. The protein levels were examined by western blotting. Immunofluorescence studies were employed for cellular localization. The gene expression was determined by RT-PCR array and qRT-PCR.A significant decrease in GABAA?1 protein, but not mRNA levels was found in the middle frontal gyrus of ASD subjects indicating a post-translational regulation of GABAA receptors in ASD. At the cellular level, treatment with proteasomal inhibitor, MG132, or lactacystin significantly increased GABAA?1 protein levels and Lys48-linked polyubiquitination of GABAA?1, but reduced proteasome activity in mouse primary cortical neurons (DIV 14 from E16 embryos). Moreover, treatment with betulinic acid, a proteasome activator significantly decreased GABAA?1 protein levels in cortical neurons indicating the role of polyubiquitination of GABAA?1 proteins with their subsequent proteasomal degradation in cortical neurons. Ubiquitination specific RT-PCR array followed by western blot analysis revealed a significant increase in SYVN1, an endoplasmic reticulum (ER)-associated degradation (ERAD) E3 ubiquitin ligase in the middle frontal gyrus of ASD subjects. In addition, the inhibition of proteasomal activity by MG132 increased the expression of GABAA?1 in the ER. The siRNA knockdown of SYVN1 significantly increased GABAA?1 protein levels in cortical neurons. Moreover, reduced association between SYVN1 and GABAA?1 was found in the middle frontal gyrus of ASD subjects.SYVN1 plays a critical role as an E3 ligase in the ubiquitin proteasome system (UPS)-mediated GABAA?1 degradation. Thus, inhibition of the ubiquitin-proteasome-mediated GABAA?1 degradation may be an important mechanism for preventing GABAA?1 turnover to maintain GABAA?1 levels and GABA signaling in ASD.

Dataset Information

Site-specific differences in proteasome-dependent degradation of monoubiquitinated ?-synuclein.

Publications

Site-specific differences in proteasome-dependent degradation of monoubiquitinated α-synuclein.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets