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!
Molecular Force Sensors
20.09.2017 | Max-Planck-Institut für Biochemie
Foster tadpoles trigger parental instinct in poison frogs
20.09.2017 | Veterinärmedizinische Universität Wien
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...
Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
20.09.2017 | Life Sciences
20.09.2017 | Power and Electrical Engineering
20.09.2017 | Physics and Astronomy