Methionine sulfoxide reductase regulates brain catechol-O-methyl transferase activity

Area of Science:

• Neuroscience
• Biochemistry
• Genetics

Background:

• Catechol-O-methyl transferase (COMT) degrades dopamine (DA) in the brain.
• Reduced COMT activity increases prefrontal cortex DA, potentially mitigating cognitive deficits.
• A common COMT polymorphism (Val/Met108) affects its activity through post-translational modifications.

Purpose of the Study:

• To investigate the impact of methionine oxidation on COMT activity.
• To determine the role of methionine sulfoxide reductase (Msr) in modulating COMT activity.
• To explore the interaction between COMT and Msr enzymes.

Main Methods:

• Utilized recombinant COMT proteins (Val/Met108) and wild-type (WT) and MsrA knockout mice.
• Employed enzymatic activity assays and Western blot analysis.
• Assessed COMT activity under varying oxidative conditions.

Main Results:

• MsrA positively regulated recombinant COMT activity, particularly under oxidative stress.
• MsrA knockout mice displayed reduced COMT activity compared to WT controls.
• Methionine oxidation appears to decrease COMT activity.

Conclusions:

• Msr enzymes are key regulators of COMT activity in the brain.
• Methionine oxidation influences COMT activity, potentially impacting dopamine levels.
• Further research is needed to determine Msr's role in cognitive functions and schizophrenia.