S-glutathionylation enhances human cystathionine β-synthase activity under oxidative stress conditions.

ABSTRACT:

Aims

Cystathionine β-synthase (CBS) catalyzes the first and rate-limiting step in the two-step trans-sulfuration pathway that converts homocysteine to cysteine. It is also one of three major enzymes responsible for the biogenesis of H2S, a signaling molecule. We have previously demonstrated that CBS is activated in cells challenged by oxidative stress, but the underlying molecular mechanism of this regulation has remained unclear.

Results

Here, we demonstrate that S-glutathionylation of CBS enhances its activity ∼2-fold in vitro. Loss of this post-translational modification in the presence of dithiothreitol results in reversal to basal activity. Cys346 was identified as the site for S-glutathionylation by a combination of mass spectrometric, mutagenesis, and activity analyse

SUBMITTER: Niu WN 

PROVIDER: S-EPMC4307034 | biostudies-literature | 2015 Feb

REPOSITORIES: biostudies-literature