RT Journal Article
SR Electronic
T1 NO-mediated cytoprotection: Instant adaptation to oxidative stress in bacteria
JF Proceedings of the National Academy of Sciences of the United States of America
JO Proc Natl Acad Sci U S A
FD National Academy of Sciences
SP 13855
OP 13860
DO 10.1073/pnas.0504307102
VO 102
IS 39
A1 Gusarov, Ivan
A1 Nudler, Evgeny
YR 2005
UL http://www.pnas.org/content/102/39/13855.abstract
AB Numerous sophisticated systems have been described that protect bacteria from increased levels of reactive oxygen species. Although indispensable during prolonged oxidative stress, these response systems depend on newly synthesized proteins, and are hence both time and energy consuming. Here, we describe an “express” cytoprotective system in Bacillus subtilis which depends on nitric oxide (NO). We show that NO immediately protects bacterial cells from reactive oxygen species by two independent mechanisms. NO transiently suppresses the enzymatic reduction of free cysteine that fuels the damaging Fenton reaction. In addition, NO directly reactivates catalase, a major antioxidant enzyme that has been inhibited in vivo by endogenous cysteine. Our data also reveal a critical role for bacterial NO-synthase in adaptation to oxidative stress associated with fast metabolic changes, and suggest a possible role for NO in defending pathogens against immune oxidative attack.