The BAG2 and BAG5 proteins inhibit the ubiquitination of pathogenic ataxin3-80Q

Abstract

The expansion of a polyglutamine domain in the protein ataxin3 causes spinocerebellar ataxia type-3 (SCA3). However, there is little information to date about the upstream proteins in the ubiquitin-proteasome system of pathogenic ataxin3-80Q. Here, we report that BAG2 (Bcl-2 associated athanogene family protein 2) and BAG5 (Bcl-2-associated athanogene family protein 5) stabilise pathogenic ataxin3-80Q by inhibiting its ubiquitination as determined based on western blotting and co-immunofluorescence experiments. The association of the BAG2 and BAG5 proteins with pathogenic ataxin3-80Q strengthens the important roles of the BAG family in neurodegenerative diseases.

KEYWORDS:

• BAG2
• BAG5
• spinocerebellar ataxia type-3
• pathogenic ataxin3-80Q
• ubiquitin-proteasome system

Acknowledgements

The authors would like to thank Dr. Ying Zheng, Dr. Fei Erkang, Dr. Li Bin, Dr. Chen Dong, Dr. Hu Qingsong, Dr. Xu Ranjie, Dr. Fu Kai, Dr. Wang Ying, Dr. Fan Huadong, Dr. Zhou Tian, Dr. Zhou Liang and Dr. Gao Feng of the University of Science and Technology of China for providing helpful advice.

Declaration of Interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this paper.

Funding: This work was supported by grants from the Major State Basic Research Development Program of China (973 Program) (2011CB 510000), the National Natural Science Foundation of China (30900469, 81130021, 81171198, 81200870, 81000542, 81371405) and Central South University Graduate Innovation Fund of Independent Exploration (2014zzts076).