Featured Research

from universities, journals, and other organizations

Breakthrough: Sensors monitor cells at work

Date:
July 2, 2013
Source:
Carnegie Institution
Summary:
Transport proteins are responsible for moving materials such as nutrients and metabolic products through a cell's outer membrane, which seals and protects all living cells, to the cell's interior. A team has now developed a groundbreaking new way to measure the activity of transporter proteins in living organisms.

AmTrac, shown here as a three-dimensional model, is an ammonium transporter coupled to a fluorescent protein , which allows the researchers to monitor the activity of the transport protein as it works to move ammonium into the cell.
Credit: The model image is courtesy of Susana Andrade, U. Freiburg, Germany

Transport proteins are responsible for moving materials such as nutrients and metabolic products through a cell's outer membrane, which seals and protects all living cells, to the cell's interior. These transported molecules include sugars, which can be used to fuel growth or to respond to chemical signals of activity or stress outside of the cell. Measuring the activity of transporter proteins in a living organism has been a challenge for scientists, because the methods are difficult, often require the use of radioactive tracers, and are hard to use in intact tissues and organs.

A team led by Wolf Frommer, director of Carnegie's Plant Biology Department, has now developed a groundbreaking new way to overcome this technology gap. This new technology has major implications not just for plant biology, but also for cellular biology research in every type of organism, including humans. Their work is published by eLife.

"With the advent of biosensors, we could measure energy dynamics and concentrations of various cellular intermediates, which allowed us to get a first-level picture of metabolic networks," Frommer said. "But we had not been able to directly follow enzyme or transporter activity or to monitor their regulation in a live organism."

Frommer and his team hypothesized that it may be possible to probe transport activity by spying on the structural rearrangements that a transporter undergoes as it moves its target molecule across the membrane barrier. They decided to do this by encoding environmentally sensitive fluorescent tags in the cell's DNA.

The team -- which included Carnegie's Roberto De Michele, Cindy Ast, Chen-Hsun Ho, Viviane Lanquar, and Guido Grossman -- focused on the transporter responsible for moving the ammonium into a cell. This activity is very important in plants, fungi, and bacteria, because ammonium serves as the key source of nitrogen in these organisms. But in excess ammonium becomes toxic. Therefore, its concentration must be very carefully regulated. The transporter for ammonium is conserved in plants, fungi, and, bacteria. It is also present in humans, where it is generally known as the Rhesus factor and plays an important role in kidney function and male fertility.

The team's approach has provided new insights into how the plant ammonium transporter works. And their sensor concept is expected to find many other applications to monitor other types of transporters and transporters in other organisms outside of the plant kingdom and even enzymes.

"For example, in humans such sensors could be used to help understand neurotransmitter transport in the brain or identify new drugs targets," Frommer said.


Story Source:

The above story is based on materials provided by Carnegie Institution. Note: Materials may be edited for content and length.


Journal Reference:

  1. Roberto De Michele, Cindy Ast, Dominique Loquι, Cheng-Hsun Ho, Susana LA Andrade, Viviane Lanquar, Guido Grossmann, Sφren Gehne, Michael U Kumke, Wolf B. Fluorescent sensors reporting the activity of ammonium transceptors in live cells. eLife, 2013 DOI: 10.7554/eLife.00800

Cite This Page:

Carnegie Institution. "Breakthrough: Sensors monitor cells at work." ScienceDaily. ScienceDaily, 2 July 2013. <www.sciencedaily.com/releases/2013/07/130702100800.htm>.
Carnegie Institution. (2013, July 2). Breakthrough: Sensors monitor cells at work. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2013/07/130702100800.htm
Carnegie Institution. "Breakthrough: Sensors monitor cells at work." ScienceDaily. www.sciencedaily.com/releases/2013/07/130702100800.htm (accessed September 30, 2014).

Share This



More Plants & Animals News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

California University Designs Sustainable Winery

California University Designs Sustainable Winery

Reuters - US Online Video (Sep. 27, 2014) — Amid California's worst drought in decades, scientists at UC Davis design a sustainable winery that includes a water recycling system. Vanessa Johnston reports. Video provided by Reuters
Powered by NewsLook.com
Argentina Worries Over Decline of Soybean Prices

Argentina Worries Over Decline of Soybean Prices

AFP (Sep. 27, 2014) — The drop in price of soy on the international market is a cause for concern in Argentina, as soybean exports are a major source of income for Latin America's third largest economy. Duration: 01:10 Video provided by AFP
Powered by NewsLook.com
Mama Bear, Cubs Hang out in California Backyard

Mama Bear, Cubs Hang out in California Backyard

Reuters - US Online Video (Sep. 27, 2014) — A mama bear and her two cubs climb trees, wrestle and take naps in the backyard of a Monrovia, California home. Vanessa Johnston reports. Video provided by Reuters
Powered by NewsLook.com
'Crazy' Climate Forces Colombian Farmers to Adapt

'Crazy' Climate Forces Colombian Farmers to Adapt

AFP (Sep. 26, 2014) — Once upon a time, farming was a blissfully low-tech business on Colombia's northern plains. Duration: 02:05 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins