Featured Research

from universities, journals, and other organizations

Turn Back, Wayward Axon: Coreceptors Work Together As 'Navigators' For A Growing Axon, Study Shows

Date:
March 15, 2009
Source:
Rockefeller University Press
Summary:
To a growing axon, the protein RGMa is a "Wrong Way" sign, alerting it to head in another direction. As a new study shows, translating that signal into cellular action requires teamwork from two receptors.

An elongating axon tip (left) crumples when it encounters RGMa (right).
Credit: Hata, K., et al. 2009. J. Cell Biol. doi:10.1083/jcb.200807029

To a growing axon, the protein RGMa is a "Wrong Way" sign, alerting it to head in another direction. As Hata et al. demonstrate in the March 9, 2009 issue of the Journal of Cell Biology (http://www.jcb.org), translating that signal into cellular action requires teamwork from two receptors.

During development, new synapses form when the growing axon of one neuron reaches another neuron. As an axon searches out the path to its destination, it bends toward so-called attractive guidance molecules and veers away from repulsive guidance molecules such as RGMa. For example, if the tip of an axon touches a glial cell instead of a neuron, the extension pulls back. On its membrane the glial cell sports RGMa, which latches onto the receptor neogenin on the axon. Researchers knew that the interaction between RGMa and neogenin halted the axon by activating the GTPase RhoA. However, they didn't know how neogenin switches on RhoA.

Hata et al. discovered that it gets help from another axon membrane receptor called Unc5B. The researchers found that after a dose of RGMa, the tip of a growing axon halted and often retreated. Eliminating Unc5B prevented this collapse.

Neogenin and Unc5B stick together and serve as coreceptors, performing slightly different tasks, Hata et al. conclude. Neogenin's job is to hook up with RGMa. Unc5B, by contrast, never contacts RGMa. Instead, it serves as a docking point for the RhoA activator LARG. Unc5B indirectly switches on RhoA by interacting with LARG.

But that left one further mystery to explain. LARG clings to Unc5B all the time, so why does it fire up RhoA only in response to RGMa? The researchers found that binding of RGMa prodded another protein, the focal adhesion kinase (FAK), to switch on LARG, allowing activation of RhoA. How RGMa binding triggers FAK is the next question the researchers want to answer.


Story Source:

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


Journal Reference:

  1. Hata et al. Unc5B associates with LARG to mediate the action of repulsive guidance molecule. The Journal of Cell Biology, 2009; 184 (5): 737 DOI: 10.1083/jcb.200807029

Cite This Page:

Rockefeller University Press. "Turn Back, Wayward Axon: Coreceptors Work Together As 'Navigators' For A Growing Axon, Study Shows." ScienceDaily. ScienceDaily, 15 March 2009. <www.sciencedaily.com/releases/2009/03/090309092826.htm>.
Rockefeller University Press. (2009, March 15). Turn Back, Wayward Axon: Coreceptors Work Together As 'Navigators' For A Growing Axon, Study Shows. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2009/03/090309092826.htm
Rockefeller University Press. "Turn Back, Wayward Axon: Coreceptors Work Together As 'Navigators' For A Growing Axon, Study Shows." ScienceDaily. www.sciencedaily.com/releases/2009/03/090309092826.htm (accessed August 1, 2014).

Share This




More Health & Medicine News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

House Republicans Vote to Sue Obama Over Healthcare Law

House Republicans Vote to Sue Obama Over Healthcare Law

Reuters - US Online Video (July 31, 2014) The Republican-led House of Representatives votes to sue President Obama, accusing him of overstepping his executive authority in making changes to the Affordable Care Act. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Despite Health Questions, E-Cigs Are Beneficial: Study

Despite Health Questions, E-Cigs Are Beneficial: Study

Newsy (July 31, 2014) Citing 81 previous studies, new research out of London suggests the benefits of smoking e-cigarettes instead of regular ones outweighs the risks. Video provided by Newsy
Powered by NewsLook.com
Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
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:
from the past week

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