Related Experiment Videos
Protection from nitrosative stress by yeast flavohemoglobin
1Howard Hughes Medical Institute, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
Summary
Yeast flavohemoglobin protects Saccharomyces cerevisiae from nitrosative stress by consuming nitric oxide (NO). This discovery reveals a conserved function and potential antimicrobial target.
Area of Science:
- Microbiology
- Biochemistry
- Molecular Biology
Background:
- Yeast flavohemoglobin, discovered 50 years ago, has an unknown function.
- Nitrosative stress poses a threat to cellular function and viability.
Purpose of the Study:
- To elucidate the function of yeast flavohemoglobin.
- To investigate its role in protecting Saccharomyces cerevisiae from nitrosative stress.
Main Methods:
- Gene deletion of YHB1 in Saccharomyces cerevisiae.
- Incubation with nitric oxide (NO) donors and S-nitrosothiols.
- Measurement of protein nitrosylation levels.
- Assessment of cell growth under nitrosative and oxidative stress conditions.
- Phylogenetic analysis of microorganismal flavohemoglobins.
Main Results:
- Deletion of YHB1 abolished nitric oxide (NO)-consuming activity in yeast.
- yhb1 mutant yeast exhibited over 10-fold higher protein nitrosylation after NO exposure.
- Mutant cell growth was significantly inhibited by nitrosative stress, unlike wild-type cells.
- Yeast flavohemoglobin protected against NO and S-nitrosothiols under both aerobic and anaerobic conditions.
- Resistance to oxidative stress remained unimpaired in yhb1 mutants.
Conclusions:
- Yeast flavohemoglobin functions to protect Saccharomyces cerevisiae from nitrosative stress.
- Its primary role is nitric oxide (NO) detoxification.
- Protection from nitrosative stress is a conserved function among microorganismal flavohemoglobins.
- Flavohemoglobin represents a potential antimicrobial therapy target.