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!
An ion channel with a doorkeeper: The pH of calcium ions controls ion channel opening
25.06.2019 | Johannes Gutenberg-Universität Mainz
Symbiotic upcycling: Turning “low value” compounds into biomass
25.06.2019 | Max-Planck-Institut für Marine Mikrobiologie
From June 25th to 27th 2019, the Fraunhofer Institute for Digital Media Technology IDMT in Ilmenau (Germany) will be presenting a new solution for acoustic quality inspection allowing contact-free, non-destructive testing of manufactured parts and components. The method which has reached Technology Readiness Level 6 already, is currently being successfully tested in practical use together with a number of industrial partners.
Reducing machine downtime, manufacturing defects, and excessive scrap
The quality of additively manufactured components depends not only on the manufacturing process, but also on the inline process control. The process control ensures a reliable coating process because it detects deviations from the target geometry immediately. At LASER World of PHOTONICS 2019, the Fraunhofer Institute for Laser Technology ILT will be demonstrating how well bi-directional sensor technology can already be used for Laser Material Deposition (LMD) in combination with commercial optics at booth A2.431.
Fraunhofer ILT has been developing optical sensor technology specifically for production measurement technology for around 10 years. In particular, its »bd-1«...
The well-known representation of chemical elements is just one example of how objects can be arranged and classified
The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...
Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.
Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...
Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.
The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...
24.06.2019 | Event News
29.04.2019 | Event News
17.04.2019 | Event News
25.06.2019 | Architecture and Construction
25.06.2019 | Life Sciences
25.06.2019 | Power and Electrical Engineering