Featured Research

from universities, journals, and other organizations

Cell death pathway linked to mitochondrial fusion

Date:
January 25, 2011
Source:
University of California - Davis
Summary:
New research provides insight into why some body organs are more susceptible to cell death than others and could eventually lead to advances in treating or preventing heart attack or stroke.

New research led by UC Davis scientists provides insight into why some body organs are more susceptible to cell death than others and could eventually lead to advances in treating or preventing heart attack or stroke.

Related Articles


In a paper published Jan. 21 in the journal Molecular Cell, the UC Davis team and their collaborators at the National Institutes of Health and Johns Hopkins University report that Bax, a factor known to promote cell death, is also involved in regulating the behavior of mitochondria, the structures that provide energy inside living cells.

Mitochondria constantly split and fuse. The proteins that control the splitting of mitochondria also promote a process called apoptosis, or programmed cell death. In contrast, the proteins that control mitochondrial fusion help protect against cell death. Cell death can happen when cells are starved of oxygen, for example during a heart attack or stroke.

Yeast have a single protein that controls outer membrane fusion, but both human and mouse cells have two proteins, called MFN1 and MFN2, which control outer membrane fusion. Using mitochondria from cells derived from genetically modified "knockout" mice, Suzanne Hoppins, a postdoctoral researcher at UC Davis, and Jodi Nunnari, a professor of molecular cell biology, studied how these two proteins work together and the role specific genes play in that process.

The research team discovered that these proteins combine with themselves or each other to form a tether between two mitochondria, leading to fusion. All three combinations -- MFN1/MFN1, MFN1/MFN2 and MFN2/MFN2 -- can promote membrane fusion, but the combination of MFN1/MFN2 is by far the most efficient, Hoppins said.

Hoppins also found that a soluble form of Bax, a protein that triggers apoptosis, can also stimulate mitochondria to fuse. It acts only through the MFN2/MFN2 combination, she found.

The form of Bax that promotes mitochondrial fusion is different from the type that leads to cell death, Nunnari said. Bax leads to cell death when it inserts itself in the mitochondrial membrane. In its soluble, free-floating form, it causes mitochondria to fuse instead.

MFN1 and MFN2 are found in different amounts in different body organs. MFN2 is more abundant in the brain and heart -- tissues where cell death can have disastrous consequences.

The paper shows how MFN2 could act to protect the brain or heart from cell death, by using Bax in a different form, Nunnari said.

"This shows that the fusion machine is both positively and negatively regulated in cells and opens doors to finding the regulatory mechanisms and discovering ways to increase or decrease the sensitivity of cells to apoptosis," Hoppins said. That could lead to new drugs that save cells, for heart disease and stroke, or that kill cells, for cancer.

Co-authors of the study are UC Davis graduate student Megan Cleland; UC Davis postdoctoral researchers Frank Edlich and Soojay Banerjee; and Richard Youle, a senior investigator at the National Institute for Neurological Disorders and Stroke; and J. Michael McCaffery, a professor at Johns Hopkins University.

The research was supported by grants from the National Institutes of Health. Hoppins recently received a K99 "Young Investigator" award from the NIH.


Story Source:

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


Journal Reference:

  1. Suzanne Hoppins, Frank Edlich, Megan M. Cleland, Soojay Banerjee, J. Michael McCaffery, Richard J. Youle, Jodi Nunnari. The Soluble Form of Bax Regulates Mitochondrial Fusion via MFN2 Homotypic Complexes. Molecular Cell, 2011; 41 (2): 150 DOI: 10.1016/j.molcel.2010.11.030

Cite This Page:

University of California - Davis. "Cell death pathway linked to mitochondrial fusion." ScienceDaily. ScienceDaily, 25 January 2011. <www.sciencedaily.com/releases/2011/01/110124162712.htm>.
University of California - Davis. (2011, January 25). Cell death pathway linked to mitochondrial fusion. ScienceDaily. Retrieved December 17, 2014 from www.sciencedaily.com/releases/2011/01/110124162712.htm
University of California - Davis. "Cell death pathway linked to mitochondrial fusion." ScienceDaily. www.sciencedaily.com/releases/2011/01/110124162712.htm (accessed December 17, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Wednesday, December 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

UN: Up to One Million Facing Hunger in Ebola-Hit Countries

UN: Up to One Million Facing Hunger in Ebola-Hit Countries

AFP (Dec. 17, 2014) Border closures, quarantines and crop losses in West African nations battling the Ebola virus could lead to as many as one million people going hungry, UN food agencies said on Wednesday. Duration: 00:52 Video provided by AFP
Powered by NewsLook.com
When You Lose Weight, This Is Where The Fat Goes

When You Lose Weight, This Is Where The Fat Goes

Newsy (Dec. 17, 2014) Can fat disappear into thin air? New research finds that during weight loss, over 80 percent of a person's fat molecules escape through the lungs. Video provided by Newsy
Powered by NewsLook.com
Flu Outbreak Closing Schools in Ohio

Flu Outbreak Closing Schools in Ohio

AP (Dec. 17, 2014) A wave of flu illnesses has forced some Ohio schools to shut down over the past week. State officials confirmed one pediatric flu-related death, a 15-year-old girl in southern Ohio. (Dec. 17) Video provided by AP
Powered by NewsLook.com
Yoga Could Be As Beneficial For The Heart As Walking, Biking

Yoga Could Be As Beneficial For The Heart As Walking, Biking

Newsy (Dec. 17, 2014) Yoga can help your weight, blood pressure, cholesterol and heart just as much as biking and walking does, a new study suggests. Video provided by Newsy
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


Health & Medicine

Mind & Brain

Living & Well

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