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 Nonstop Tranport of Cargo in Nanomachines
20.11.2018 | Max-Planck-Institut für molekulare Zellbiologie und Genetik

nachricht Researchers find social cultures in chimpanzees
20.11.2018 | Universität Leipzig

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Nonstop Tranport of Cargo in Nanomachines

Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.

Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Coherence Tomography: German-Japanese Research Alliance hosted Medical Imaging Conference

19.11.2018 | Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

 
Latest News

Nonstop Tranport of Cargo in Nanomachines

20.11.2018 | Life Sciences

Researchers find social cultures in chimpanzees

20.11.2018 | Life Sciences

When AI and optoelectronics meet: Researchers take control of light properties

20.11.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>