Featured Research

from universities, journals, and other organizations

Golgi Apparatus: Simple Explanation For How Baffling Structure Works

Date:
October 16, 2009
Source:
University of California - San Diego
Summary:
Researchers have provided a surprisingly simple explanation for the mechanism and features of the "Golgi apparatus" -- a structure that has baffled generations of scientists. The new model developed by scientists suggests that the Golgi's unusual shape is a direct consequence of the way it works.

This is a new model of the Golgi apparatus.
Credit: UC San Diego School of Medicine

A research team at the University of California, San Diego School of Medicine has provided a surprisingly simple explanation for the mechanism and features of the "Golgi apparatus" – a structure that has baffled generations of scientists. The model developed by the UC San Diego scientists suggests that the Golgi's unusual shape is a direct consequence of the way it works.

Their study will be published in the October 16 issue of the journal Cell.

The Golgi apparatus serves as a processing center for the exportation of proteins, lipids and other large molecules to their final destinations outside of the cell.

"Its primary function is to serve as a way station for extracellular protein traffic," said principal investigator Seth J. Field, assistant professor of medicine at UC San Diego. "Much of our body is made up of material exported by cells – for example, antibodies, hormones, growth factors, even much of the material that makes up bone, cartilage, skin, and hair – and they all depend on the Golgi apparatus working correctly."

The Golgi apparatus is made up of flattened, membrane-bound stacks called cisternae, but the reason for their shape and structure have been unclear since the Golgi was first identified by Nobel Prize winner George Palade and colleagues using an electron microscope more than 50 years ago. Each cisterna is made up of a flattened disk that carries enzymes meant to help or modify the protein cargo that travels through them.

Golgi membranes, from yeast to human cells, rely on a particular type of lipid signaling molecule – phosphatidylinositol-4-phosphate, or PtdIns(4)P – for normal trafficking. Field was a 2008 winner of the NIH New Innovator award to study the function of a group of these lipid signaling molecules called phosphoinositides, which are known to play critical roles in regulating cell growth and death, metabolism, and communication processes within cells. His search to understand the function of these molecules led to what he described as an unexpected discovery about how PtdIns(4)P contributes to the structure of the Golgi.

Using a proteomic lipid binding screen, Field and colleagues identified a particular Golgi protein, GOLPH3 which links to PtdIns(4)P and to a contractile protein similar to those found in muscle called MYO18A. They discovered that this three-way interaction applies a tensile force that is required for efficient formation of the tubules and vesicles necessary for extracellular transportation.

Their research suggests that another consequence of this tensile force is to stretch the Golgi into the extended ribbon observed by fluorescence microscopy and the familiar flattened form observed by electron microscopy.

"The NIH New Innovator Program is an effort to find exceptionally creative approaches to major challenges in biomedical and behavioral research," said NIH Director Francis S. Collins, MD, PhD. "Dr. Field has fulfilled that promise with an extraordinary insight into the origin of a structure and a process that has perplexed biologists for decades. He has shown that an interaction of three particular proteins is essential for Golgi apparatus function and, remarkably, that this interaction also generates the force that shapes the apparatus into the flattened ribbons first observed by electron microscopy half a century ago. He has given us considerably deeper insight into the mechanism of the Golgi apparatus and a stunning example of the linkage between form and function."

Additional contributors to the paper include Holly C. Dippold, Michelle M. Ng, Suzette E. Farber-Katz, Sun-Kyung Lee, Marshall C. Peterman, Ronald Sim, Patricia A. Wiharto and Kenneth A. Galbraith of UCSD's Division of Endocrinology and Metabolism, Department of Medicine; Monica L. Kerr and Swetha Madhavarapu of Beth Israel-Deaconess Medical Center; Greg J. Fuchs and Huilin Zhou of the Ludwig Institute for Cancer Research; and Marilyn G. Farquhar and Timo Meerloo, UCSD Department of Cellular and Molecular Medicine.

The work was supported in part by the National Institute of Diabetes and Digestive and Kidney Diseases of the NIH; an American Cancer Society Fellowship; the Burroughs Wellcome Fund; the V Foundation; and an NIH New Innovator Award to Seth Field.


Story Source:

The above story is based on materials provided by University of California - San Diego. Note: Materials may be edited for content and length.


Cite This Page:

University of California - San Diego. "Golgi Apparatus: Simple Explanation For How Baffling Structure Works." ScienceDaily. ScienceDaily, 16 October 2009. <www.sciencedaily.com/releases/2009/10/091015123548.htm>.
University of California - San Diego. (2009, October 16). Golgi Apparatus: Simple Explanation For How Baffling Structure Works. ScienceDaily. Retrieved August 30, 2014 from www.sciencedaily.com/releases/2009/10/091015123548.htm
University of California - San Diego. "Golgi Apparatus: Simple Explanation For How Baffling Structure Works." ScienceDaily. www.sciencedaily.com/releases/2009/10/091015123548.htm (accessed August 30, 2014).

Share This




More Plants & Animals News

Saturday, August 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Newsy (Aug. 29, 2014) In a new study, a promising experimental treatment for Ebola managed to cure a group of infected macaque monkeys. Video provided by Newsy
Powered by NewsLook.com
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

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