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.
Sheets of programmable matter can be made to pop into complex 3D shapes 100 times taller than their original thickness when heated, and could find uses in medicine
A particle physics student has used his downtime to build a Lego model of the world's most powerful particle accelerator, the Large Hadron Collider (LHC), and is now lobbying the toy company to take it to market.
Get the full the story behind a $761 jar of peanut butter and other exorbitantly priced everyday objects used by scientists
Satellite imagery shows 20 new craters around holes discovered last year in Siberia
Young maths whizz from Iran uses simple equations to paint stunning images that bizarrely look like marine objects, and makes a fractal Africa
A new breed of the hyper-accurate clocks could help scientists detect the elusive ripples in space-time faster and cheaper
Replacing the spark plugs in engines with lasers could lead to more complete fuel combustion and greener cars
After a two-year hiatus, the Large Hadron Collider will restart soon, twice as strong and with some "dark" mysteries to unlock
Global antibiotic resistance is imperilling our existence. We need clever ways to find new bug-beating drugs
If dark matter turns out to interact with photons, its glow would be visible at the edges of spiral galaxies – now we just have to find it