We have examined the chemical and functional reversibility of oxidative modification in myosin. Redox regulation has emerged as a crucial modulator of protein function, with particular relevance to aging. We previously identified a single methionine residue in Dictyostelium discoideum (Dicty) myosin II (M394, near the myosin cardiomyopathy loop in the actin-binding interface) that is functionally sensitive to oxidation. We now show that oxidation of M394 is reversible by methionine sulfoxide reductase (Msr), restoring actin-activated ATPase activity. Sequence alignment reveals that M394 of Dicty myosin II is a cysteine residue in all human isoforms of skeletal and cardiac myosin. Using Dicty myosin II as a model for site-specific redox sensitivity of this Cys residue, the M394C mutant can be glutathionylated in vitro, resulting in reversible inhibition of actin-activated ATPase activity, with effects similar to those of methionine oxidation at this site. This work illustrates the potential for myosin to function as a redox sensor in both non-muscle and muscle cells, modulating motility/contractility in response to oxidative stress.
|Original language||English (US)|
|Number of pages||5|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Oct 24 2014|
Bibliographical noteFunding Information:
We thank Margaret Titus for expert consultation regarding Dicty myosin. We thank Ivan Rayment for the S1dC plasmid. This work was supported by NIH grants to DDT ( R37 AG026160 ) and RJM ( F31 AG037303 ) and from AHA to DEO ( 12UFEL12040063 ). We received excellent assistance with mass spectrometry from Bruce Witthuhn at the Center for Mass Spectrometry and Proteomics at the University of Minnesota. The Biophysical Spectroscopy Center and Biomedical Genomics Center at the University of Minnesota were essential for this work.
© 2014 Elsevier Inc.
- Methionine sulfoxide reductase (Msr)
- Myosin II
- Reactive oxygen species (ROS)