The nitric oxide system in cells is “a major biological signaling pathway that has been missed with regard to the way it controls proteins,” and it is linked to cancer and other diseases when the system goes awry, said Jonathan Stamler, M.D., a professor of medicine and biochemistry at Duke University Medical Center who worked on the study.
In the body, nitric oxide plays a role in the transport of oxygen to tissues and physiological activities such as the transmission of nerve impulses, and the beating of the heart. When things go awry with the nitric oxide system, bad things can happen in bodies, according to recent studies. For instance, there may be too little nitric oxide in atherosclerosis and there may be too much in Parkinson’s disease; there may not be enough nitric oxide in sickle cell disease and there may be too much in some types of diabetes, Stamler said.
The new findings, which Stamler said change understanding of how the nitric oxide system is controlled, appear in the May 23 issue of the journal Science.
“What we see now for the first time in the Science paper is that there are enzymes that are removing NO from proteins to control protein activity,” Stamler said. “This action has a broad-based effect, frankly, and probably happens in virtually all cells and across all protein classes. Nitric oxide is implicated in many disease processes. Sepsis, asthma, cystic fibrosis, Parkinson’s disease, heart failure, malignant hyperthermia -- all of these diseases are linked to aberrant nitric-oxide-based signaling.”
An important factor that previously wasn’t appreciated, he said, is that the target of nitric oxide in disease is different in every case. The finding of how nitric oxide binding to proteins is regulated opens the field for new refinement in biochemical research, said Stamler, who has been studying nitric oxide in cells for 15 years.
“Now we will need to study whether the aberrant cell signals are a matter of too much NO being produced and added to proteins or not enough being removed from proteins,” he said. “It is not simply a matter of too much or too little NO being in cells, but rather how much is being added or taken away from specific proteins, which is quite a different thing.”
First author on the paper, Moran Benhar, Ph.D., and co-author Douglas Hess, Ph.D., are both in the Duke Department of Medicine. Co-author Michael Forrester is a graduate student in the Duke Department of Biochemistry.
The research explains that the enzymes thioredoxin 1 and thioredoxin 2 remove nitric oxide from the amino acid cysteine within mammalian cells, thereby regulating several different actions in cells. One result of this removal is the activation of molecules that begin apoptosis, which is the normal programmed death of a cell. This process has potential importance for many diseases, including inflammatory diseases, heart failure and cancer. Because thioredoxins are established targets of drug therapy for arthritis, the research suggests potential therapeutic applications of the process.
The nitric oxide system is analogous to the much more studied phosphorylation system, in which phosphates are added and removed from proteins, the paper said. Changes in phosphorylation are among the most common causes of disease, and proteins that regulate phosphorylation are major drug targets, Stamler said.
“Aberrant dephosphosphorylation causes disease. Expect the same for denitrosylation,” Stamler said.
Similar research at Duke that was published in the journal Nature on March 16 supports Stamler’s findings. Christopher Counter, an associate professor in the Duke Department of Pharmacology and Cancer Biology, and colleagues found that eNOS (endothelial nitric oxide synthase), an enzyme that enhances the creation of nitric oxide, promoted tumor development and tumor maintenance in mice.
“The Chris Counter work is especially exciting because he shows that a nitric oxide synthase is linked to cancer, and he specifically identifies the protein that is the target of the nitric oxide, the protein that gets turned on through S-nitrosylation,” Stamler said. Blocking S-nitrosylation of this protein prevented cancer.
The steady stream of new papers on nitric oxide seems to underscore Stamler’s long-held belief that nitric oxide affects cells in bigger ways than many had appreciated. “When we began our studies two decades ago, we hypothesized that nitric oxide was part of a significant, broad-based system,” Stamler said. “Our hypothesis never changed.”
Mary Jane Gore | EurekAlert!
New yeast species discovered in Braunschweig, Germany
13.12.2019 | Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH
Saliva test shows promise for earlier and easier detection of mouth and throat cancer
13.12.2019 | Elsevier
Vaccinia viruses serve as a vaccine against human smallpox and as the basis of new cancer therapies. Two studies now provide fascinating insights into their unusual propagation strategy at the atomic level.
For viruses to multiply, they usually need the support of the cells they infect. In many cases, only in their host’s nucleus can they find the machines,...
More than one hundred and fifty years have passed since the publication of James Clerk Maxwell's "A Dynamical Theory of the Electromagnetic Field" (1865). What would our lives be without this publication?
It is difficult to imagine, as this treatise revolutionized our fundamental understanding of electric fields, magnetic fields, and light. The twenty original...
In a joint experimental and theoretical work performed at the Heidelberg Max Planck Institute for Nuclear Physics, an international team of physicists detected for the first time an orbital crossing in the highly charged ion Pr⁹⁺. Optical spectra were recorded employing an electron beam ion trap and analysed with the aid of atomic structure calculations. A proposed nHz-wide transition has been identified and its energy was determined with high precision. Theory predicts a very high sensitivity to new physics and extremely low susceptibility to external perturbations for this “clock line” making it a unique candidate for proposed precision studies.
Laser spectroscopy of neutral atoms and singly charged ions has reached astonishing precision by merit of a chain of technological advances during the past...
The ability to investigate the dynamics of single particle at the nano-scale and femtosecond level remained an unfathomed dream for years. It was not until the dawn of the 21st century that nanotechnology and femtoscience gradually merged together and the first ultrafast microscopy of individual quantum dots (QDs) and molecules was accomplished.
Ultrafast microscopy studies entirely rely on detecting nanoparticles or single molecules with luminescence techniques, which require efficient emitters to...
Graphene, a two-dimensional structure made of carbon, is a material with excellent mechanical, electronic and optical properties. However, it did not seem suitable for magnetic applications. Together with international partners, Empa researchers have now succeeded in synthesizing a unique nanographene predicted in the 1970s, which conclusively demonstrates that carbon in very specific forms has magnetic properties that could permit future spintronic applications. The results have just been published in the renowned journal Nature Nanotechnology.
Depending on the shape and orientation of their edges, graphene nanostructures (also known as nanographenes) can have very different properties – for example,...
03.12.2019 | Event News
15.11.2019 | Event News
15.11.2019 | Event News
13.12.2019 | Physics and Astronomy
13.12.2019 | Physics and Astronomy
13.12.2019 | Materials Sciences