Featured Research

from universities, journals, and other organizations

Mathematical Model Gives Clearer Picture Of Physics Of Cells, Organelles

Date:
December 15, 2008
Source:
University of California - Los Angeles
Summary:
Cells are filled with membrane-bound organelles like the nucleus, mitochondria and endoplasmic reticula. Over the years, scientists have made much progress in understanding the biomolecular details of how these organelles function within cells, but understanding the actual physical forces that maintain the structures of these organelles' membranes continues to be a challenge. Mathematicians have recently devised a new mathematical procedure for accurately predicting the 3-D forces involved in creating and maintaining certain organelle membrane structures that could one day shed light on the lifecycle of membrane-bound viruses such as HIV.

Cells are filled with membrane-bound organelles like the nucleus, mitochondria and endoplasmic reticula. Over the years, scientists have made much progress in understanding the biomolecular details of how these organelles function within cells, but understanding the actual physical forces that maintain the structures of these organelles' membranes continues to be a challenge.

Related Articles


Now, UCLA Henry Samueli School of Engineering and Applied Science researcher William Klug and colleagues from the California Institute of Technology and the Whitehead Institute for Biomedical Research in Massachusetts have devised a mathematical procedure for accurately predicting the three-dimensional forces involved in creating and maintaining certain organelle membranes.

Their study, which appears Dec. 8 in Proceedings of the National Academy of Sciences and is currently available online, could potentially shed light on the life cycles of membrane-bound viruses such as HIV.

"The study is exciting because it provides a roadmap for ways we can do predictive computational science," said Klug, an assistant professor of mechanical and aerospace engineering. "The mathematical model is able to provide us with a quantitative understanding of the physics of cells that is essentially impossible to obtain directly by experiment."

To understand the researchers' mathematical description of how forces can lead to deformations in a membrane, one can consider the simple concept of a bathroom scale.

"When you step on a scale, a small spring in the scale defines how heavy you are or what force is being applied to the scale," said study co-author Paul Wiggins, a fellow at the Whitehead Institute. "Similarly, with membranes, springs or forces cause them to bend. In a sense, we wanted to see if we could play the same game with the organelles of a cell — to take the observed structure and see if we can predict what forces are applied to give rise to the structure and essentially hold the structure together."

The team used an artificial biomembrane to investigate the dynamic forces that act on a cell's membrane and organelles. With optical tweezers — a scientific instrument that uses a focused laser beam to provide an attractive or repulsive force — they were able to trap and move parts of the cell. This enabled the researchers to exert known forces in different ways, giving them an opportunity to analyze both the response of the membranes when their structures were changed dramatically and to validate their mathematical procedure for predicting forces based on the deformed shapes of the membranes.

"We have this geometry, so what are the forces?" said Klug. "It seems straightforward if you write it out mathematically but in practice, actually measuring the forces reliably where you can quantify the error is really tricky."

The researchers believe that understanding the forces and mechanisms that are responsible for maintaining the geometries of the organelles will help them uncover the crucial factors that lead to changes or malfunctions in organelles.

"When cells undergo oxygen damage, that usually leads to a change in the structure of the mitochondria — the specialized organelles often referred to as the powerhouses of cells," Wiggins said. "There is a close link between the ability of the mitochondria to function and its structure. By relating structure to force, we can uncover the crucial factors that lead to the change in the structure of the mitochondria and other organelles as well."

Membrane-bound viruses like HIV infect cells and then replicate and break from the cells by budding. This budding process eventually uses up the cell membrane and kills it.

"The forces that lead to the process of budding are essentially unknown," Klug said. "Researchers have looked at the image data of HIV in different stages of budding to try to understand the forces that lead up to it. If we can eventually understand what those forces are, we might be able to come up with a way to disrupt the viral assembly process. And that's a different strategy than what is being done today to treat retroviruses and HIV in particular."


Story Source:

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


Cite This Page:

University of California - Los Angeles. "Mathematical Model Gives Clearer Picture Of Physics Of Cells, Organelles." ScienceDaily. ScienceDaily, 15 December 2008. <www.sciencedaily.com/releases/2008/12/081208180508.htm>.
University of California - Los Angeles. (2008, December 15). Mathematical Model Gives Clearer Picture Of Physics Of Cells, Organelles. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2008/12/081208180508.htm
University of California - Los Angeles. "Mathematical Model Gives Clearer Picture Of Physics Of Cells, Organelles." ScienceDaily. www.sciencedaily.com/releases/2008/12/081208180508.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Research on Bats Could Help Develop Drugs Against Ebola

Research on Bats Could Help Develop Drugs Against Ebola

AFP (Nov. 28, 2014) In Africa's only biosafety level 4 laboratory, scientists have been carrying out experiments on bats to understand how virus like Ebola are being transmitted, and how some of them resist to it. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
New Dinosaur Species Found in Museum Collection

New Dinosaur Species Found in Museum Collection

Reuters - Innovations Video Online (Nov. 27, 2014) A British palaeontologist has discovered a new species of dinosaur while studying fossils in a Canadian museum. Pentaceratops aquilonius was related to Triceratops and lived at the end of the Cretaceous Period, around 75 million years ago. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Tryptophan Isn't Making You Sleepy On Thanksgiving

Tryptophan Isn't Making You Sleepy On Thanksgiving

Newsy (Nov. 27, 2014) Tryptophan, a chemical found naturally in turkey meat, gets blamed for sleepiness after Thanksgiving meals. But science points to other culprits. Video provided by Newsy
Powered by NewsLook.com
Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani 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:

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