Featured Research

from universities, journals, and other organizations

Yeast Provides Evidence For Continuous Membrane Theory

Date:
April 5, 1999
Source:
University Of Chicago
Summary:
Researchers at the University of Chicago have new evidence to support a controversial theory about tiny intracellular structures called organelles. Their findings support the theory that certain organelles form an interconnected system where one organelle gives rise to another through outgrowths of its own membrane.

Researchers at the University of Chicago have new evidence to support a controversial theory about tiny intracellular structures called organelles. Their findings support the theory that certain organelles form an interconnected system where one organelle gives rise to another through outgrowths of its own membrane.

Their discoveries will also shed light on disorders such as Menkes disease and polycystic kidney disease, which are caused by defects in Golgi function.

The researchers studied a particular region of the cell where an organelle called the endoplasmic reticulum (ER) seems to give rise to another organelle called the Golgi apparatus. This process occurs at specific places along the ER called transitional ER (tER) sites.

"Our work strongly suggests that the Golgi apparatus grows directly out of the tER," says Benjamin Glick, assistant professor at the University of Chicago and lead author of the paper in the April 5 issue of the Journal of Cell Biology.

The Golgi apparatus, which consists of a stack of pancake-shaped membranes called cisternae, is responsible for modifying and packaging proteins for export to the cell surface. According to the membrane outgrowth theory, Golgi cisternae are transient structures, with new cisternae constantly being generated at tER sites.

Glick realized he had a unique opportunity to test this hypothesis when he noticed very different-looking Golgi formations in two yeast species: Pichia pastoris, which has the typical coherent stacked Golgi cisternae, and Saccharomyces cerevisiae, or brewer's yeast, which has dispersed individual cisternae scattered throughout the cell.

"We used these two yeasts because they are closely related, yet they have completely different Golgi structures. Saccharomyces is definitely an oddity because almost every other kind of cell has well-organized Golgi stacks. We reasoned that the dispersed Golgi in Saccharomyces might be explained by an unusual organization of the tER," Glick says.

Glick and his team created a fluorescent protein that specifically marks tER sites and introduced it into Pichia and Saccharomyces cells. The result was striking. A single Pichia cell has a small number of tER sites, each giving rise to a Golgi stack. But in Saccharomyces, the entire ER lights up with the fluorescent marker, indicating that Saccharomyces lacks well-defined tER sites, and that Golgi cisternae can therefore arise from any place along the ER.

Glick is not sure why Saccharomyces has a delocalized tER and a dispersed Golgi. "This strange organization might somehow be beneficial for this yeast. Or it might just be an accident of evolution. At this stage we're still guessing," he says. "But we can take advantage of the differences between the two yeasts to uncover the mechanisms that produce tER sites."

Like Pichia, mammalian cells have discrete tER sites that give rise to Golgi cisternae. By using yeasts as a model system, the researchers hope to arrive at a broad understanding of how Golgi stacks are formed and maintained.


Story Source:

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


Cite This Page:

University Of Chicago. "Yeast Provides Evidence For Continuous Membrane Theory." ScienceDaily. ScienceDaily, 5 April 1999. <www.sciencedaily.com/releases/1999/04/990405065609.htm>.
University Of Chicago. (1999, April 5). Yeast Provides Evidence For Continuous Membrane Theory. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/1999/04/990405065609.htm
University Of Chicago. "Yeast Provides Evidence For Continuous Membrane Theory." ScienceDaily. www.sciencedaily.com/releases/1999/04/990405065609.htm (accessed September 22, 2014).

Share This



More Health & Medicine News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Liberia Pleads for Help to Fight Ebola

Liberia Pleads for Help to Fight Ebola

AP (Sep. 22, 2014) Liberia's finance minister is urging the international community to quickly follow through on pledges of cash to battle Ebola. Bodies are piling up in the capital Monrovia as the nation awaits more help. (Sept. 22) Video provided by AP
Powered by NewsLook.com
Ebola Doctor Says Border Controls Critical

Ebola Doctor Says Border Controls Critical

AP (Sep. 22, 2014) A Florida doctor who helped fight the expanding Ebola outbreak in West Africa says the disease can be stopped, but only if nations quickly step up their response and make border control a priority. (Sept. 22) Video provided by AP
Powered by NewsLook.com
Global Ebola Aid Increasing But Critics Say It's Late

Global Ebola Aid Increasing But Critics Say It's Late

Newsy (Sep. 21, 2014) More than 100 tons of medical supplies were sent to West Africa on Saturday, but aid workers say the global response is still sluggish. Video provided by Newsy
Powered by NewsLook.com
Sierra Leone in Lockdown to Control Ebola

Sierra Leone in Lockdown to Control Ebola

AP (Sep. 21, 2014) Sierra Leone residents remained in lockdown on Saturday as part of a massive effort to confine millions of people to their homes in a bid to stem the biggest Ebola outbreak in history. (Sept. 20) 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