Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Watching the production of new proteins in live cells

27.08.2013
Columbia researchers make significant step in understanding and imaging protein synthesis

Researchers at Columbia University, in collaboration with biologists in Baylor College of Medicine, have made a significant step in understanding and imaging protein synthesis, pinpointing exactly where and when cells produce new proteins.


This image shows stimulated Raman scattering imaging of newly synthesized protein in live hippocampal neurons incubated in a deuterium-labeled amino acids medium for 20 hours by targeting the unique 2,133 cm_1 vibrational peak of C-D stretching.

Credit: Lu Wei, Columbia University

Assistant Professor Wei Min's team developed a new technique to produce high-resolution imaging of newly synthesized proteins inside living cells. The findings were published in the July 9th issue of The Proceedings of the National Academy of Sciences (Volume 110; Issue 28).

Proteins carry out almost every crucial biological function. Synthesis of new proteins is a key step in gene expression and is a major process by which cells respond rapidly to environmental cues in physiological and pathological conditions, such as cancer, autism and oxidative stress. A cell's proteome (i.e., the sum of all the cell's proteins) is highly dynamic and tightly regulated by both protein synthesis and disposal to maintain homeostasis and ensure normal functioning of the body. Many intricate biological processes, such as cell growth, differentiation and diseases, involve new protein synthesis at a specific location and time.

In particular, long-lasting neuronal plasticity (changes in neural pathways and synapses that come from alterations in behavior, environment and bodily injury), such as those underlying learning and long-term memory, require new protein synthesis in a site- and time- dependent manner inside neurons.

Min and colleagues' new technique harnesses deuterium (a heavier cousin of the normal hydrogen atom), which was first discovered by Harold Urey in 1932, also at Columbia University. When hydrogen is replaced by deuterium, the biochemical activities of amino acids change very little. When added to growth media for culturing cells, these deuterium-labeled amino acids are incorporated by the natural cell machineries as the necessary building blocks for new protein production. Hence, only newly synthesized proteins by living cells will carry the special deuterium atoms connected to carbon atoms. The carbon-deuterium bonds vibrate at a distinct frequency, different from almost all natural chemical bonds existing inside cells.

The Columbia team utilized an emerging technique called stimulated Raman scattering (SRS) microscopy to target the unique vibrational motion of carbon-deuterium bonds carried by the newly synthesized proteins. They found that by quickly scanning a focused laser spot across the sample, point-by-point, SRS microscopy is capable of delivering location-dependent concentration maps of carbon-deuterium bonds inside living cells.

"Incorporation of deuterium-labeled amino acids to new proteins is minimally disruptive, and their biochemical properties are almost identical to their natural counterparts," says Lu Wei, the lead author of the paper. "Our technique is highly sensitive, specific, and compatible with living systems under physiological conditions that don't require killing cells or staining."

Prior to this discovery, the ability to observe protein synthesis in living cells had eluded scientists, who devoted extensive efforts to achieving this goal. A classic strategy that involves labeling amino acids with radioisotopes to trace and quantify proteome dynamics requires the samples be killed and exposed to films. Fluorescence microscopy, another popular method, takes advantage of the inherent glowing of green fluorescent protein (GFP) to follow a protein. While this process does work on individual proteins, scientists can't observe the cell's entire proteome. A third technique, bioorthogonal noncanonical amino acid tagging (BONCAT) metabolically incorporates unnatural (biosynthetic) amino acids containing reactive chemical groups. However, the method generally requires killing cells and subsequent dye staining, a process that presents an issue for live tissues and animals. Therefore, it is extremely challenging and desirable to quantitatively image proteome synthesis in living cells, tissues and animals with high resolution. Min's research opens the door for a new method to study living cells, presenting opportunities to understand previously unanswered questions about the behavior of cells as they perform their functions.

The next step for Min's team is to capture where and when a new protein is produced inside brain tissues when an animal is subject to various lab exercises to form long-term memory. "Our new technique will greatly facilitate understanding the molecular mechanisms of many complex behaviors such as learning and diseases," he says.

Beth Kwon | EurekAlert!
Further information:
http://www.columbia.edu

More articles from Life Sciences:

nachricht The birth of a new protein
20.10.2017 | University of Arizona

nachricht Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>