Featured Research

from universities, journals, and other organizations

Marine Snail Toxin Targeted At African Toad Eggs Reveals Novel Impact On The Regulation Of Serotonin

Date:
July 27, 1998
Source:
University Of California, San Francisco
Summary:
Researchers have long known that the wily marine snail known as conus geographus uses a toxic venom to stun its prey into submission. Now, researchers led by a UC San Francisco scientist have determined that proteins extracted from the venom prevent serotonin, a key chemical messenger in the nervous system, from acting at a particular molecular gateway, or receptor, in African toad eggs. The receptor is also found in the human brain.

Researchers have long known that the wily marine snail known as conus geographus uses a toxic venom to stun its prey into submission.

Now, researchers led by a UC San Francisco scientist have determined that proteins extracted from the venom prevent serotonin, a key chemical messenger in the nervous system, from acting at a particular molecular gateway, or receptor, in African toad eggs. The receptor is also found in the human brain.

The finding, reported in the current issue of Science, could provide a model for exploring the way in which serotonin and several other neurotransmitter receptors are regulated in humans, according to one of the authors of the study,

David Julius, PhD, an associate professor of cellular and molecular pharmacology at UCSF. And as serotonin plays a key role in regulating nerve cell behavior, understanding the way in which it functions paves the way for designing new drugs to control its actions.

One existing drug that targets the receptor, known as 5-HT3, is used to treat nausea that accompanies chemotherapy. Drugs targeting the receptor could potentially be designed to treat pain and anxiety, said Julius.

Serotonin and the hundreds of other neurotransmitters zipping through the brain act as chemical messengers between nerve cells. They are released from one neuron and move at the rate of milliseconds to another, where they bind to a particular molecular gateway within the cell. There, like a key turned in a keyhole, they "unlock" the gateway, transmitting their chemical message into the cell, telling it either to fire an electrical output, or nerve signal, or hold off on firing.

The ultimate goal of the current study, said lead author Laura England, PhD, a postdoctoral candidate in Julius's lab, is to use the toxins that have been isolated to probe the site at which serotonin binds to the receptor and understand what the molecular pocket at which it binds looks like.

"If you can do that, and figure out what the molecular contacts are between a neurotransmitter and its receptor, then you have the information you need, potentially, to design drugs," she said.

While the study focused on proteins found in a species not usually likened to humans, the leap to the human nervous system is not unrealistic, as much of the human nervous system is made up of molecules that have been conserved through evolution. The marine snail toxins have long been known to act on numerous cell receptor families within the mammalian nervous system. What hadn't been known is that they act on serotonin receptors.

As there are already numerous good drugs that act on this particular serotonin receptor, 5-HT3, it is unclear whether the research will lead to the design of better drugs, said Julius. However, the receptor is a member of a large family of receptors and contains the same structural motif as the receptors for the neurotransmitters acetycholine, GABA and glycine. Therefore, he said, "it provides a model system for understanding how this big class of channels works."

While researchers do know that the toxic peptides released by marine snail venom rapidly immobilize prey by creating neuromuscular and sensory blockades and stimulating shock, they do not know for certain that this occurs in part as a result of serotonin inhibition. It is possible, however, that this a contributing factor, said Julius.

Researchers from the University of Utah, including Baldomero M. Olivera, and The Salk Institute for Biological Studies, including A. Grey Craig and Jean Rivier, also participated in the study.


Story Source:

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


Cite This Page:

University Of California, San Francisco. "Marine Snail Toxin Targeted At African Toad Eggs Reveals Novel Impact On The Regulation Of Serotonin." ScienceDaily. ScienceDaily, 27 July 1998. <www.sciencedaily.com/releases/1998/07/980727080701.htm>.
University Of California, San Francisco. (1998, July 27). Marine Snail Toxin Targeted At African Toad Eggs Reveals Novel Impact On The Regulation Of Serotonin. ScienceDaily. Retrieved August 29, 2014 from www.sciencedaily.com/releases/1998/07/980727080701.htm
University Of California, San Francisco. "Marine Snail Toxin Targeted At African Toad Eggs Reveals Novel Impact On The Regulation Of Serotonin." ScienceDaily. www.sciencedaily.com/releases/1998/07/980727080701.htm (accessed August 29, 2014).

Share This




More Plants & Animals News

Friday, August 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Raw: Australian Sheep Gets Long Overdue Haircut

Raw: Australian Sheep Gets Long Overdue Haircut

AP (Aug. 28, 2014) Hoping to break the record for world's wooliest, Shaun the sheep came up 10 pounds shy with his fleece weighing over 50 pounds after being shorn for the first time in years. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Minds Blown: Scientists Develop Fish That Walk On Land

Minds Blown: Scientists Develop Fish That Walk On Land

Newsy (Aug. 28, 2014) Canadian scientists looking into the very first land animals took a fish out of water and forced it to walk. Video provided by Newsy
Powered by NewsLook.com
Fake Dogs Scare Real Geese from Wis. Park

Fake Dogs Scare Real Geese from Wis. Park

AP (Aug. 28, 2014) Parks officials in Stevens Point, Wisconsin had a fowl problem. Canadian Geese were making a mess of a park, so officials enlisted cardboard versions of man's best friend. (Aug. 28) Video provided by AP
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