Featured Research

from universities, journals, and other organizations

Newly Identified Enzyme Group Converts Protein Into Cellular Traffic Signal

Date:
June 2, 2005
Source:
University Of Georgia
Summary:
An international research team has identified a new group of enzymes that may help uncover how cells direct internal traffic. The discovery has future implications for conditions -- such as polycystic kidney disease, male infertility, behavioral disorders and cancer -- that involve defects in protein fibers called microtubules.

Tetrahymena stained with flourescent dye shows locations of microtubules.
Credit: Jacek Gaertig, University of Georgia, Athens

Athens, Ga. -- An international research team has identified a new group of enzymes that may help uncover how cells direct internal traffic. The discovery has future implications for conditions -- such as polycystic kidney disease, male infertility, behavioral disorders and cancer -- that involve defects in protein fibers called microtubules. The findings, which will be prereleased online in Science Express on May 12 will be published in a June issue of the journal Science.

Related Articles


The team was co-led by Jacek Gaertig, associate professor of cellular biology at the University of Georgia, and Bernard Eddé of the National Center for Scientific Research (CNRS) in France.

Cells have an internal highway system made of fibers called microtubules. Specialized motor proteins slide along these fibers, carrying organelles and other materials to the places they need to go. But how do motor proteins know where to take their cargoes?

The researchers identified a new enzyme group that attaches an unusual molecular tag to a component of the cell's microtubular highway system. The tag is attached to a localized region of a microtubule and may act like a road sign on the interstate, directing motor proteins to take the "proper exit" to the nucleus or the cell membrane.

"We've known for more than a decade that strings of glutamic acid an amino acid are sometimes attached to the side of a protein called tubulin," said Gaertig, one of the senior co-authors on the paper. Tubulin is a component of microtubules. "This modification occurs in all cells but is abundant in neurons in the brain."

Few other proteins are modified in this way. But investigating what the modification does and how it works has been difficult until now.

The authors have identified a new group of enzymes -- called polyglutamylases -- that attach glutamic acid chains of varying length and branching patterns.

Because the enzyme complex is active only for a short window during development in mice, it took a "biochemical tour de force" by collaborators in France to purify it.

In Gaertig's group, doctoral student Krzysztof Rogowski then identified the enzyme complex's active subunit and postdoctoral associate Dorota Wloga found genes for these enzymes in many organisms including humans. The researchers also showed that these enzymes can modify just a portion of a microtubular highway, an important discovery that suggests the mechanism for directing cell traffic. The lab studied polyglutamylases from the unicellular pond protist Tetrahymena, a model organism that has abundant modified microtubules and shares many of the same properties of internal cell traffic as animal cells.

"Although it has been known for some time that polyglutamylation occurs, the function of these glutamic acid chains on microtubules have, until now, remained completely obscure," Eve Ida Barak, a program director for the National Science Foundation, said in an e-mail.

This research paves the way for detailed studies of what polyglutamylate modification does and how it works.

The UGA research team was supported by an NSF grant.

For more information on Jacek Gaertig's research, log on to http://gaertig4.cb.uga.edu.


Story Source:

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


Cite This Page:

University Of Georgia. "Newly Identified Enzyme Group Converts Protein Into Cellular Traffic Signal." ScienceDaily. ScienceDaily, 2 June 2005. <www.sciencedaily.com/releases/2005/05/050527105307.htm>.
University Of Georgia. (2005, June 2). Newly Identified Enzyme Group Converts Protein Into Cellular Traffic Signal. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/2005/05/050527105307.htm
University Of Georgia. "Newly Identified Enzyme Group Converts Protein Into Cellular Traffic Signal." ScienceDaily. www.sciencedaily.com/releases/2005/05/050527105307.htm (accessed October 24, 2014).

Share This



More Plants & Animals News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) — Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) — One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) — Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. Video provided by Newsy
Powered by NewsLook.com
Weird-Looking Dinosaur Solves 50-Year-Old Mystery

Weird-Looking Dinosaur Solves 50-Year-Old Mystery

Newsy (Oct. 23, 2014) — You've probably seen some weird-looking dinosaurs, but have you ever seen one this weird? It's worth a look. Video provided by Newsy
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