The study examined a recently discovered enzyme called PMR1. That enzyme attaches to certain mRNA molecules and remains there like a hand grenade with its pin in place.
These mRNAs carry the information for making highly potent proteins, proteins that cells must stop making suddenly. When that ‘stop' command arrives, the pin is pulled and the enzyme destroys the mRNA, quickly halting production of that protein.
This new study found, however, that under stress conditions, the same enzyme – while attached to the mRNA – helps form temporary shelters within the cell called stress granules. There, the mRNA can be protected so that production of the protein can quickly resume whenever the stress ends, perhaps insuring that the cell survives.
Stress granules are short-lived aggregates of mRNA and proteins, and they accumulate when cells are subjected to conditions such as starvation, low oxygen (which can occur within large tumors), chemotherapy or radiation therapy.
The study, led by researchers at Ohio State University's Comprehensive Cancer Center, is published in the December issue of the journal Molecular and Cellular Biology.
“The stress response protects cells from these conditions by sequestering mRNAs for those proteins not specifically involved in the stress response itself,” says principal investigator Daniel R. Schoenberg, professor of molecular and cellular biochemistry and a researcher with Ohio State's Comprehensive Cancer Center.
“By understanding how PMR1 and similar enzymes are incorporated into stress granules and inactivated, we may be able to learn how to block this protective mechanism and make it harder for cancer cells to survive cancer therapies.”
Schoenberg first discovered the PMR1 enzyme in 1995, and his lab has been actively studying it since that time.
For this study, Schoenberg and a group of colleagues wanted to learn if the enzyme also destroys its mRNA during periods of stress.
To answer the question, they used cultured cells to which they'd added active and mutant forms of the enzyme. They then stressed the cells using the chemical arsenite, a relative of arsenic.
The investigators found that during stress, the enzyme interacts directly with another protein called TIA-1, a key protein involved in assembling stress granules. This interaction draws the enzyme-mRNA complex into stress granules.
But the researchers were unable to detect any sign that the message was destroyed.
“The fact that we don't see an acceleration of mRNA decay suggests that something in the stress response protects these mRNAs from being degraded, even though the degrading enzyme PMR1 is there in the stress granules with its target mRNA.”
Schoenberg and his colleagues will next study the other proteins within stress granules to try to learn how PMR1-mRNA complex is preserved.
Funding from the National Institute of General Medical Sciences supported this research.
Schoenberg collaborated on this study with Nancy Kedersha at Brigham and Women's Hospital and Harvard Medical School.
Darrell E. Ward | EurekAlert!
Scientists unlock ability to generate new sensory hair cells
22.02.2017 | Brigham and Women's Hospital
New insights into the information processing of motor neurons
22.02.2017 | Max Planck Florida Institute for Neuroscience
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
22.02.2017 | Power and Electrical Engineering
22.02.2017 | Life Sciences
22.02.2017 | Physics and Astronomy