Corporate Banner
Satellite Banner
Proteomics
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Study Finds How Stressed-Out Cells Halt Protein Synthesis

Published: Wednesday, January 09, 2013
Last Updated: Wednesday, January 09, 2013
Bookmark and Share
Researchers also find protein-making can be resumed once stress has passed.

Cells experience stress in multiple ways. Temperature shifts, mis-folded proteins and oxidative damage can all cause cellular stress. But whatever the form of the stress, all cells quickly stop making proteins when under pressure.

A new Cornell study unravels how cells rapidly stall protein synthesis during stress and then resume their protein-making activities once the stress has passed.

If proteins continued to synthesize during stress, cells would waste energy, and damaged proteins would build up, leading to toxicity and disease.

Previously, researchers thought that during stress protein synthesis was only controlled at the point where the translation machinery starts to read mRNA, a DNA transcript carrying protein codes.

But the new study, published online Jan. 3 in the journal Molecular Cell, reports that the protein synthesis can actually be halted midway, during the subsequent phase in the protein synthesis process, called elongation, where proteins are being made in a long chain of amino acids, like ground beef coming out of a grinder.

The researchers used a technique they developed to monitor the protein synthesis process that involves ribosomes, which decode mRNA and build chains of amino acids, a protein's building blocks. They found, in the presence of stress and mis-folded proteins, the ribosomes pause during the early elongation process, when new peptides (chains of amino acids) were made but were still less than 50 amino acids long.

"We were very surprised," said Shu-Bing Qian, assistant professor of nutritional sciences at Cornell and the paper's senior author. "We thought it would pause everywhere, but we only found ribosomes pausing within the first 50 amino acids. We realized the translation machinery must have a mechanism for controlling trafficking in this region."

When peptides are made, they emerge from a tunnel at the end of the ribosome that is about 30 to 50 amino acids long. "Inside the tunnel, newly formed peptides are hidden from the outer environment," said Qian. But once they emerge, molecules called chaperones help to pull them from the ribosome.

The researchers found that under stress, chaperones were not present to pull the nascent peptides out as they emerged from the tunnel. The chaperones were instead recruited to help peptides -- damaged by conditions in the cell caused by stress -- refold into proteins.

"Our study shows that chaperones not only help folding but also control the ribosomes," said Qian. "We used chemical inhibitors to inhibit the chaperones in unstressed cells, and they paused in exactly the same place."

While Qian and colleagues looked at this process during stress caused by protein mis-folding, they believe the same process occurs no matter the source of stress.

If peptides were continuously produced during stress, they would become damaged and would accumulate, leading to toxicity and disease. Cancer cells, which grow out of control, have very high levels of chaperones for continuous protein synthesis. Researchers have developed chaperone inhibitors as a way of curbing cancer. Such inhibitors were used in this study to inhibit the chaperones in normal cells.

The study was funded by the National Institutes of Health, the Ellison Medical Foundation and the Department of Defense. Botao Liu, a graduate student, and Yan Han, a former postdoctoral associate, both in Qian's lab, were lead authors of the study.


Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,900+ scientific posters on ePosters
  • More than 4,200+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Proteins Seek, Attack, Destroy Tumor Cells in Bloodstream
Using white blood cells to ferry potent cancer-killing proteins through the bloodstream virtually eliminates metastatic prostate cancer in mice, Cornell researchers have confirmed.
Friday, January 15, 2016
Gene Prevents Buildup of Misfolded Cell Proteins
For the first time, Cornell researchers have demonstrated how a gene called SEL1L plays a critical role in clearing away misfolded proteins.
Friday, January 24, 2014
Shark, Human Proteins are Surprisingly Similar
Despite widespread fascination with sharks, the world’s oldest ocean predators have long been a genetic mystery.
Friday, December 06, 2013
Gene Thought to be Linked to Alzheimer's is Marker for Only Mild Impairment
Defying the widely held belief that a specific gene is the biggest risk factor for Alzheimer's disease, report says that people with that gene are more likely to develop mild cognitive impairment -- but not Alzheimer's.
Monday, February 18, 2013
Imaging Facility adds Two Tools for Microscopy
Cornell's Imaging Facility owns microscopes, scanners and ultrasound units for revealing details that can't be seen with the naked eye.
Monday, February 18, 2013
Protein Regulates Protein Folding in Cells During Stress
Researchers link protein known for cell mobility with protein folding during stress.
Thursday, January 03, 2013
Study: How Cells form 'Trash Bags' for Recycling Waste
A class of membrane-sculpting proteins create vesicles that carry old and damaged proteins from the surface of cellular compartments into internal recycling plants where the waste is degraded and components are reused.
Tuesday, October 23, 2012
Proteins Barge in to Turn Off Unneeded Genes and Save Energy
When they activate a gene, living cells have a system in reserve to turn it off.
Friday, September 07, 2012
Cell Membrane Proteins Feel Long-Range Forces
Proteins embedded in the lipid membranes of cells feel long-range attractive forces in specific patterns that mediate the proteins' behaviour.
Wednesday, September 05, 2012
New Method Helps Researchers Decode Genomes
Although scientists sequenced the entire human genome more than 10 years ago, much work remains to understand what proteins all those genes code for.
Wednesday, September 05, 2012
Cell Membrane Proteins Feel Long-Range Forces
A team from Cornell have identified the physical mechanisms behind protein interactions, which are set off by changes in cellular membranes.
Thursday, August 30, 2012
Insights into Protein Folding May Lead to Better Flu Vaccine
New method for looking at how proteins fold allows researchers to take snapshots of ribosomes.
Friday, August 03, 2012
Bacteria Employ 'Quality-control' Machinery, say Biomolecular Engineers
Like quality-control managers in factories, bacteria possess built-in machinery that track the shape and quality of proteins trying to pass through their cytoplasmic membranes.
Friday, August 03, 2012
Scientific News
Structure of Brain Plaques in Huntington's
Researchers at the University of Pittsburgh School of Medicine have shown that the core of the protein clumps found in the brains of people with Huntington's disease have a distinctive structure, a finding that could shed light on the molecular mechanisms underlying the neurodegenerative disorder.
Visualizing a Cancer Drug Target at Atomic Resolution
Using cryo-electron microscopy, researchers were able to view, in atomic detail, the binding of a potential small molecule drug to a key protein in cancer cells.
The Power of Three
Overlooked portion of cell “death receptor” critical in some cancers, autoimmune diseases.
Biomarker for Recurring HPV-Linked Oropharyngeal Cancers
A look-back analysis of HPV infection antibodies in patients treated for oropharyngeal (mouth and throat) cancers linked to HPV infection suggests at least one of the antibodies could be useful in identifying those at risk for a recurrence of the cancer, say scientists at the Johns Hopkins University.
Light Signals from Living Cells
Fluorescent protein markers delivered under high pressure.
Cellular 'Relief Valve'
A team led by scientists at The Scripps Research Institute (TSRI) has solved a long-standing mystery in cell biology by showing essentially how a key “relief-valve” in cells does its job.
Genomic Signature Shared by Five Types of Cancer
National Institutes of Health researchers have identified a striking signature in tumor DNA that occurs in five different types of cancer.
Protein Protects Against Flu in Mice
The engineered molecule doesn’t provoke inflammation and may hail a new class of antivirals.
Cat Stem Cell Therapy Gives Humans Hope
By the time Bob the cat came to the UC Davis veterinary hospital, he had used up most of his nine lives.
Crowdfunding the Fight Against Cancer
From budding social causes to groundbreaking businesses to the next big band, crowdfunding has helped connect countless worthy projects with like-minded people willing to support their efforts, even in small ways. But could crowdfunding help fight cancer?
Scroll Up
Scroll Down
SELECTBIO

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,900+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,200+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!