α-Synuclein in central nervous system and from erythrocytes, mammalian cells, and Escherichia coli exists predominantly as disordered monomer

Bruno Fauvet, Martial K. Mbefo, Mohamed Bilal Fares, Carole Desobry, Sarah Michael, Mustafa T. Ardah, Elpida Tsika, Philippe Coune, Michel Prudent, Niels Lion, David Eliezer, Darren J. Moore, Bernard Schneider, Patrick Aebischer, Omar M. El-Agnaf, Eliezer Masliah, Hilal A. Lashuel

Research output: Contribution to journalArticle

313 Citations (Scopus)

Abstract

Since the discovery and isolation of α-synuclein (α-syn) from human brains, it has been widely accepted that it exists as an intrinsically disordered monomeric protein. Two recent studies suggested that α-syn produced in Escherichia coli or isolated from mammalian cells and red blood cells exists predominantly as a tetramer that is rich in α-helical structure (Bartels, T., Choi, J. G., and Selkoe, D. J. (2011) Nature 477, 107-110; Wang, W., Perovic, I., Chittuluru, J., Kaganovich, A., Nguyen, L. T. T., Liao, J., Auclair, J. R., Johnson, D., Landeru, A., Simorellis, A. K., Ju, S., Cookson, M. R., Asturias, F. J., Agar, J. N., Webb, B. N., Kang, C., Ringe, D., Petsko, G. A., Pochapsky, T. C., and Hoang, Q. Q. (2011) Proc. Natl. Acad. Sci. 108, 17797-17802). However, it remains unknown whether or not this putative tetramer is the main physiological form of α-syn in the brain. In this study, we investigated the oligomeric state of α-syn in mouse, rat, and human brains. To assess the conformational and oligomeric state of native α-syn in complex mixtures, we generated α-syn standards of known quaternary structure and conformational properties and compared the behavior of endogenously expressed α-syn to these standards using native and denaturing gel electrophoresis techniques, size-exclusion chromatography, and an oligomer-specific ELISA. Our findings demonstrate that both human and rodent α-syn expressed in the central nervous system exist predominantly as an unfolded monomer. Similar results were observed when human α-syn was expressed in mouse and rat brains as well as mammalian cell lines (HEK293, HeLa, and SH-SY5Y). Furthermore, we show that α-syn expressed in E. coli and purified under denaturing or nondenaturing conditions, whether as a free protein or as a fusion construct with GST, is monomeric and adopts a disordered conformation after GST removal. These results do not rule out the possibility that α-syn becomes structured upon interaction with other proteins and/or biological membranes.

Original languageEnglish
Pages (from-to)15345-15364
Number of pages20
JournalJournal of Biological Chemistry
Volume287
Issue number19
DOIs
Publication statusPublished - 4 May 2012

    Fingerprint

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

Fauvet, B., Mbefo, M. K., Fares, M. B., Desobry, C., Michael, S., Ardah, M. T., Tsika, E., Coune, P., Prudent, M., Lion, N., Eliezer, D., Moore, D. J., Schneider, B., Aebischer, P., El-Agnaf, O. M., Masliah, E., & Lashuel, H. A. (2012). α-Synuclein in central nervous system and from erythrocytes, mammalian cells, and Escherichia coli exists predominantly as disordered monomer. Journal of Biological Chemistry, 287(19), 15345-15364. https://doi.org/10.1074/jbc.M111.318949