Corporate Banner
Satellite Banner
Technology
Networks
Scientific Communities
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Study: How Cells form 'Trash Bags' for Recycling Waste

Published: Tuesday, October 23, 2012
Last Updated: Tuesday, October 23, 2012
Bookmark and Share
A class of membrane-sculpting proteins create vesicles that carry old and damaged proteins from the surface of cellular compartments into internal recycling plants where the waste is degraded and components are reused.

A Cornell study in the Oct. 12 issue of Cell may explain how these membrane-sculpting proteins, known as Endosomal Sorting Complexes Required for Transport (ESCRTs), create vesicles, a process that has remained a mystery since ESCRTs were discovered more than a decade ago.

If these "trash bags" are unable to make their deliveries, numerous diseases including cancer and neurodegenerative diseases emerge. Furthermore, viruses like HIV can hijack these membrane-sculpting proteins to burst out of infected cells.

The study was led by Mike Henne and Nicholas Buchkovich, postdoctoral researchers in the lab of Scott Emr, the paper's senior author and director of Cornell's Weill Institute for Cell and Molecular Biology. It describes how the researchers reconstituted a portion of the ESCRT machinery -- a complex known as ESCRT-III -- that bends the cellular membranes, a key step before the envelope eventually pinches off and closes to form vesicles. The researchers then visualized the membrane-bending process using a high-power electron microscope.

The researchers were able to show that proteins within the ESCRT-III complex work in stages where one protein assembles into spirals while other proteins transform these spirals further into tighter corkscrew-shaped helices, which then bend the cellular membrane prior to it forming into a vesicle.

"We believe these experiments tell us that ESCRT-III is a dynamic complex that generates vesicles by forming a spring-like filament that can bend membranes," Henne said. If true, this could be a novel method for creating membrane curvature in cells, he added.

Altogether, the ESCRT machinery is composed of five distinct complexes that must work together to do their job. These complexes are thought to recruit one another to the surface of vesicles in a specific sequence of events.

After visualizing the ESCRT-III complex, the researchers examined how ESCRT-III interacts with its neighbor and recruiter, ESCRT-II. They found that ESCRT-II controlled ESCRT-III architecture, but also works with ESCRT-III to create tiny ESCRT-III rings on the membrane surface. Since ESCRT-II contains a specialized protein responsible for grabbing trash, the researchers believe that ESCRT-II and ESCRT-III work together to first grab and then trap cellular garbage in this ESCRT-III ring before the ring eventually matures into the membrane bending spring.

Vesicles hold different cellular materials, and many of them carry protein waste. They also regulate cell-signaling receptors at the cell surface by internalizing them and thereby shutting them down, before they are carried to the cell's recycling plants, known as lysosomes, where they are degraded by digestive enzymes.

Uncovering these steps of the process opens the door for future research by Emr's lab to explore exactly how the final moment of vesicle formation -- the "pinching off" step that seals the top of the vesicular bag known as "scission" -- is mediated. Vesicle scission remains one of the outstanding questions in the field.

Henne is the 2011 Sam and Nancy Fleming Fellow. The fellowship was established in 2008 through a gift from Sam Fleming, chairman of Cornell's Life Sciences Advisory Board and former vice chairman of the Cornell Board of Trustees, and his wife, Nancy. The Flemings also support numerous academic activities in Cornell's New Life Sciences Initiative.


Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 3,200+ scientific posters on ePosters
  • More Than 4,700+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Key to Chronic Fatigue Syndrome is in Your Gut, Not Head
Researchers report they have identified biological markers of the disease in gut bacteria and inflammatory microbial agents in the blood.
Wednesday, June 29, 2016
Pathogen Takes Control of Gypsy Moth Populations
A new fungal pathogen is killing gypsy moth caterpillars and crowding out communities of pathogens and parasites that previously destroyed these moth pests.
Tuesday, April 26, 2016
Eating Green Could be in Your Genes
Genetic variation uncovered that has evolved in populations that have historically favored vegetarian diets, such as in India, Africa and parts of East Asia.
Friday, April 01, 2016
$4.8M USAID Grant to Improve Food Security
To strengthen capacity to develop and disseminate genetically engineered eggplant in Bangladesh and the Philippines, the USAID has awarded Cornell a $4.8 million, three-year cooperative grant.
Friday, April 01, 2016
Proteins Seek, Attack, Destroy Tumor Cells in Bloodstream
Using white blood cells to ferry potent cancer-killing proteins through the bloodstream virtually eliminates metastatic prostate cancer in mice, Cornell researchers have confirmed.
Friday, January 15, 2016
Tumor-suppressing Gene Lends Insight to Cancer Treatment
Researchers have found that delicate replication process derails if a gene named PTEN has mutated or is absent.
Tuesday, July 14, 2015
Synthetic Immune Organ Produces Antibodies
Cornell engineers have created a functional, synthetic immune organ that produces antibodies and can be controlled in the lab, completely separate from a living organism.
Friday, June 12, 2015
On Planes, Savory Tomato Becomes Favored Flavor
Study shows the effect that airplane noise has on passengers' taste preferences.
Friday, May 15, 2015
$5.5M NSF Grant Aims to Improve Rice Crops with Genome Editing
Researchers to precisely target, cut, remove and replace DNA in a living cell to improve rice.
Friday, May 08, 2015
'Shield' Gives Tricky Proteins a New Identity
Solubilization of Integral Membrane Proteins with high Levels of Expression.
Saturday, April 11, 2015
DNA Safeguard May Be Key In Cancer Treatment
Cornell researchers have developed a new technique to understand the actions of key proteins required for cancer cells to proliferate.
Monday, March 09, 2015
A ‘STAR’ is Born: Engineers Devise Genetic 'On' Switch
A new “on” switch to control gene expression has been developed by Cornell scientists.
Tuesday, February 03, 2015
Bacteria Be Gone!
New technology keeps bacteria from sticking to surfaces.
Monday, January 19, 2015
On the Environmental Trail of Food Pathogens
Learning where Listeria dwells can aid the search for other food pathogens.
Tuesday, December 23, 2014
Chemists Show That ALS is a Protein Aggregation Disease
Using a technique that illuminates subtle changes in individual proteins, chemistry researchers at Cornell have uncovered new insight into the underlying causes of Amyotrophic Lateral Sclerosis (ALS).
Thursday, October 23, 2014
Scientific News
ASMS 2016: Targeting Mass Spectrometry Tools for the Masses
The expanding application range of MS in life sciences, food, energy, and health sciences research was highlighted at this year's ASMS meeting in San Antonio, Texas.
Benchtop Automation Trends
Gain a better understanding of current interest in and future deployment of benchtop automated systems.
Anthrax Proteins Might Help Treat Cancerous Tumors
Studies in mice reveal novel treatment regimen.
New Cancer Drug Target Found in Dual-Function Protein
Findings from a study from TSRI have shown that targeting a protein called GlyRS might help to halt cancer growth.
Key to Chronic Fatigue Syndrome is in Your Gut, Not Head
Researchers report they have identified biological markers of the disease in gut bacteria and inflammatory microbial agents in the blood.
HIV Structure Stabilized
Findings represent ‘big accomplishment’ in biomedical engineering and design.
Four Newly-Identified Genes Could Improve Rice
A Japanese research team have applied a method used in human genetic analysis to rice and rapidly discovered four new genes that are potentially significant for agriculture. These findings could influence crop breeding and help combat food shortages caused by a growing population.
New Cancer Drug Target in Dual-Function Protein
Scientists at The Scripps Research Institute (TSRI) have identified a protein that launches cancer growth and appears to contribute to higher mortality in breast cancer patients.
Antibodies To Dengue May Alter Course Of Zika Virus Infection
Scientists at Emory Vaccine Center, in collaboration with investigators from Thailand, have found that people infected with dengue virus develop antibodies that cross-react with Zika virus.
Some Women With PCOS May Have Adrenal Disorder
Researchers at NIH have found that a subgroup of women with PCOS, a leading cause of infertility, may produce excess adrenal hormones.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
3,200+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!