Quantitative proteomics reveals neuronal ubiquitination of Rngo/Ddi1 and several proteasomal subunits by Ube3a, accounting for the complexity of Angelman syndrome
Language English Country England, Great Britain Media print
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
29788202
DOI
10.1093/hmg/ddy103
PII: 4948678
Knihovny.cz E-resources
- MeSH
- Angelman Syndrome genetics physiopathology MeSH
- Aspartic Acid Proteases genetics MeSH
- Drosophila MeSH
- Photoreceptor Cells metabolism pathology MeSH
- Humans MeSH
- Mice MeSH
- Neurons metabolism pathology MeSH
- Drosophila Proteins genetics MeSH
- Proteomics MeSH
- Gene Expression Regulation genetics MeSH
- Saccharomyces cerevisiae Proteins genetics MeSH
- Ubiquitination genetics MeSH
- Ubiquitin-Protein Ligases genetics MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Aspartic Acid Proteases MeSH
- DDI1 protein, S cerevisiae MeSH Browser
- DDI2 protein, human MeSH Browser
- Drosophila Proteins MeSH
- Saccharomyces cerevisiae Proteins MeSH
- Ube3a protein, Drosophila MeSH Browser
- UBE3A protein, human MeSH Browser
- Ubiquitin-Protein Ligases MeSH
Angelman syndrome is a complex neurodevelopmental disorder caused by the lack of function in the brain of a single gene, UBE3A. The E3 ligase coded by this gene is known to build K48-linked ubiquitin chains, a modification historically considered to target substrates for degradation by the proteasome. However, a change in protein abundance is not proof that a candidate UBE3A substrate is indeed ubiquitinated by UBE3A. We have here used an unbiased ubiquitin proteomics approach, the bioUb strategy, to identify 79 proteins that appear more ubiquitinated in the Drosophila photoreceptor cells when Ube3a is over-expressed. We found a significantly high number of those proteins to be proteasomal subunits or proteasome-interacting proteins, suggesting a wide proteasomal perturbation in the brain of Angelman patients. We focused on validating the ubiquitination by Ube3a of Rngo, a proteasomal component conserved from yeast (Ddi1) to humans (DDI1 and DDI2), but yet scarcely characterized. Ube3a-mediated Rngo ubiquitination in fly neurons was confirmed by immunoblotting. Using human neuroblastoma SH-SY5Y cells in culture, we also observed that human DDI1 is ubiquitinated by UBE3A, without being targeted for degradation. The novel observation that DDI1 is expressed in the developing mice brain, with a significant peak at E16.5, strongly suggests that DDI1 has biological functions not yet described that could be of relevance for Angelman syndrome clinical research.
1st Faculty of Medicine Charles University 12108 Prague Czech Republic
Department of Biochemistry and Molecular Biology Faculty of Pharmacy 01006 Vitoria Gasteiz Spain
Department of Genetics and Microbiology Charles University 12843 Prague Czech Republic
Functional Genomics Unit CIC bioGUNE 48160 Derio Spain
Ikerbasque Basque Foundation for Science 48013 Bilbao Spain
Proteomics Core Facility SGIKER University of the Basque Country 48940 Leioa Spain
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