Mutations in the human protein DJ-1 cause early onset of Parkinson's disease. A reactive cysteine residue (Cys <sup>106 </sup>) of DJ-1 is crucial for its protective function, although the underlying mechanisms are unclear. Here we show that a fracti ...
Mutations in the human protein DJ-1 cause early onset of Parkinson's disease. A reactive cysteine residue (Cys 106 ) of DJ-1 is crucial for its protective function, although the underlying mechanisms are unclear. Here we show that a fraction of bacterially expressed polyhistidine-tagged human DJ-1 could not be eluted from a Ni-nitrilotriacetate (Ni-NTA) column with 150 mM imidazole. This unusually tight binding was accompanied by the appearance of blue violet color on the Ni-NTA column. We demonstrate by X-ray crystallography that Cys 106 is carboxymethylated in a fraction of DJ-1 tightly bound to Ni-NTA and that the replacement of Cys 106 by serine abrogates the tight binding and the appearance of blue violet color. However, carboxymethylation of purified DJ-1 is insufficient to confer the tight binding to Ni-NTA. Moreover, when eluted protein was re-applied to the Ni-NTA column, no tight binding was observed, indicating that the formation of high affinity complex with Ni-NTA depends on a transient modification of Cys 106 that transforms into a Cys 106 -carboxymethyl adduct upon elution from Ni-NTA. We conclude that an unknown metabolite reacts with Cys 106 of DJ-1 to result in a transient post-translational modification. This modification is distinct from simple oxidation to sulfinic or sulfenic acids and confers altered binding properties to DJ-1 suggesting that it could serve as a signal for sensing oxidant stress.
Organizational Affiliation:
Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, 22908, USA.,National Center for Biotechnology, Astana, 010000, Kazakhstan.,National Center for Biotechnology, Astana, 010000, Kazakhstan; Department of Chemistry, School of Science and Technology, Nazarbayev University, Astana, 010000, Kazakhstan.,Department of Biology, School of Science and Technology, Nazarbayev University, Astana, 010000, Kazakhstan.,Department of Chemistry, School of Science and Technology, Nazarbayev University, Astana, 010000, Kazakhstan. Electronic address: darkhan.utepbergenov@nu.edu.kz.,Department of Chemistry, School of Science and Technology, Nazarbayev University, Astana, 010000, Kazakhstan.
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