Just like a comic book super hero, you could say that the enzyme superoxide dismutase (SOD1) has a secret identity. Since its discovery in 1969, scientists believed SOD1's only role was to protect living cells against damage from free radicals. Now, researchers at the Johns Hopkins Bloomberg School of Public Health have discovered that SOD1 protects cells by regulating cell energy and metabolism. The results of their research were published January 17, 2013, in the journal Cell.
Transforming oxygen to energy for growth is key to life for all living cells, which happens either through respiration or fermentation. When oxygen is plentiful, respiration normally takes over; however certain cells fail to respire in spite of abundant oxygen and instead ferment, leading to uncontrolled cell growth—a hallmark of cancer.
Using the baker's yeast S. cerevisiae as well as a human cell line, researchers Valeria C. Culotta, PhD, and colleague Amit Reddi from the Department of Biochemistry and Molecular Biology determined that SOD1 transmits signals from oxygen and glucose to repress respiration. This signaling is accomplished through SOD1 protection of another enzyme known as casein kinase 1-gamma (CK1γ), which is an important key to the switch between respiration and fermentation.
"SOD enzymes are present in virtually all living cells, from the most ancient bacteria to every cell in the human body," explained Culotta. "I've been telling my students to think of SOD1 as a superhero. It not only defends cells from damaging free radicals, but also has a secret life as a guardian of cell energy and metabolism."
"Our findings provide new clues as to how rapidly dividing cells—from yeast to human cancers—may escape the urge to respire and instead choose fermentation to promote rapid growth," said Culotta.
"SOD1 has long been recognized as an important enzyme in protection from oxidative stress, but this work establishes an important new function for the enzyme in cellular metabolism," said Vernon Anderson, PhD, of the National Institutes of Health's National Institute of General Medical Sciences, which partly funded the study. "The results provide important insight into how SOD1 and oxygen radicals push cellular energy metabolism towards fermentation, a feature of some disease states, including cancer."
Johns Hopkins University Bloomberg School of Public Health: http://www.jhsph.edu
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Researchers were surprised by what they found when they sandwiched a drop of water between two layers of an unusual two-dimensional material called graphene.
Scientists at Cern are suggesting they could soon detect miniature black holes, proving the existence of parallel universes and disproving the big bang theory of the creation of the universe.
The Curiosity rover makes a detection of nitrogen compounds which provide further evidence that ancient Mars would have been a habitable world.
Wild animals can predict earthquakes several weeks before they strike, and motion-activated cameras that track their movements could be adopted in quake-prone countries as an affordable early warning system, scientists said on Tuesday.
GENEVA (Reuters) - Scientists at Europe's CERN research center have had to postpone the imminent relaunch of their refitted 'Big Bang' machine, the Large Hadron Collider, because of a short-circuit in the wiring of one of the vital magnets.
Images taken by NASA's Dawn spacecraft show that a mysterious bright spot on dwarf planet Ceres could be a plume of water spurting from a deep, icy crater
Using seismic vibrations from earthquakes around the world, they are figuring out what Earth looks like below the surface
In honor of a very special Pi Day, enjoy this map that explores the human-made and natural structures that come closest to a perfect circle
The moon has a more complex history than previously thought with at least nine subsurface layers, results from ground-penetrating radar aboard China’s Yutu lunar rover shows, scientists said on Thursday.
Scientists at the CERN physics research center said on Thursday the mystery dark matter that makes up 96 percent of the stuff of the universe will be a prime target for their souped-up Large Hadron Collider (LHC) in the coming years.