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Published on: August 17, 2019
Myosin is reversibly inhibited by S-nitrosylation
Leonardo Nogueira1, Cicero Figueiredo-Freitas, Gustavo Casimiro-Lopes
1Instituto de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, RJ 21941-590, Brazil.
The Biochemical Journal
|September 15, 2009
Summary
Exercise increases protein S-nitrosylation in skeletal muscle, with myosin being the primary target. This modification affects myosin
Area of Science:
- Muscle physiology
- Biochemistry
- Exercise science
Background:
- Nitric oxide (NO) is produced in skeletal muscle and its levels rise with physical activity.
- The role of NO and its derivatives in modifying muscle proteins, particularly myosin, remains unclear.
Purpose of the Study:
- To investigate whether myosin is a target of NO or its derivatives during muscle contraction.
- To explore the impact of S-nitrosylation on myosin function and structure.
Main Methods:
- Incubation of skinned skeletal muscle fibers and myotubes with S-nitrosothiols (SNOs).
- Reaction of isolated myosin with S-nitrosoglutathione and diethylamine NONOate.
- Assessment of myosin ATPase activity and S-nitrosylation levels.
- Chemical modification of myosin thiols using N-ethylmaleimide.
Main Results:
- Exercise elevates protein S-nitrosylation in skeletal muscle.
- Myosin is the main target for exogenous SNOs in muscle fibers and myotubes.
- S-nitrosylation of myosin by S-nitrosoglutathione inhibits ATPase activity.
- Myosin requires transnitrosylation for S-nitrosylation, not direct reaction with NO.
- Stable S-nitrosylation sites on myosin are not essential for ATPase activity.
Conclusions:
- Exercise induces S-nitrosylation of skeletal muscle myosin.
- S-nitrosylation of myosin by SNOs can modulate its activity.
- This pathway represents a novel link between exercise and muscle protein modification with potential physiological relevance.
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