Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mechanism controls movement of cell structures

17.02.2003


UI researchers discover new mechanism controlling movement of cell structures



Organelles are compartments and structures inside cells that perform varied and vital functions, including energy production, storage and transportation of important substances and removal of waste products. Normal cellular function requires that organelles be positioned in specific locations in a cell. Thus, movement of the organelles to their appropriate destinations is critical.

A team of University of Iowa researchers has discovered a new mechanism that helps explain how organelles are delivered to the right place at the right time. The research findings appear in the Feb. 16 Nature Advance Online Publication.


Understanding how organelles get to their assigned cellular locations will improve understanding of embryonic development and may have implications for understanding many diseases including cancer and diabetes, said Lois Weisman, Ph.D., UI associate professor of biochemistry and principal investigator of the study.

Weisman and her colleagues made their discovery by studying organelle movement in yeast. The team identified a protein that specifically couples vacuoles (yeast organelles) to the organelle transportation system and also appears to plays a key role in controlling the timing and delivery of the vacuole to its final destination.

Most yeast proteins have direct humans counterparts known as homologs. This similarity makes yeast a good experimental organism because almost everything researchers learn about yeast cells is likely to be applicable to human cells, too. In addition, manipulating and analyzing yeast genes is much easier and faster than working with higher life forms.

The machinery that moves vacuoles in yeast also moves other organelles, as well. One question that interested Weisman and her colleagues was: how can this same mechanism move different organelles to different locations at different times?

The transport system acts like a cable car with motor molecules transporting organelles through the cell along cable-like structures. The protein discovered by the UI team specifically couples vacuoles to a motor molecule. The studies also suggest that when the vacuole arrives at its correct destination, the coupling protein is degraded, which causes the vacuole to be deposited in the right location.

"The protein we have discovered is called Vac17p. We found that it is involved in the specific coupling of vacuoles to the motor protein," Weisman said. "More surprisingly, we also found that regulation of the appearance and disappearance of this protein controls when that organelle moves and where it moves to."

Working with various yeast mutants, Fusheng Tang, Ph.D., UI postdoctoral researcher and lead author of the study, discovered that if the Vac17p protein does not get degraded, then the release mechanism is disrupted and the vacuole is not deposited in the correct cellular location. His research suggests that the controlled assembly and disassembly of the molecular transport complexes is critical for accurate and directed organelle movement.

"We were just trying to figure out how the specific coupling mechanism worked and then we also discovered this protein turnover mechanism, which seems to be critical for depositing the cargo at the right place and time," Weisman said.

Because the organelle transport system in yeast is essentially the same as the system found in higher animals including humans, the researchers believe that regulated disassembly of organelle transportation complexes may be a general mechanism for moving organelles to their final cellular destinations in all cells.



In addition to Weisman and Tang, other UI researchers involved in the study included research assistants, Emily Kauffman, Jennifer Novak and Johnathan Nau, and Natalie Catlett, Ph.D., who was a graduate student in Weisman’s lab.

The research was funded by grants from the National Institutes of Health and the National Science Foundation.

STORY SOURCE: University of Iowa Health Science Relations, 5135 Westlawn, Iowa City, Iowa 52242-1178

WRITER: Jennifer Brown, jennifer-l-brown@uiowa.edu
MEDIA CONTACT: Becky Soglin, (319) 335-6660, becky-soglin@uiowa.edu

PHOTOS/GRAPHICS: A photo of Weisman is available for downloading at http:// www.biochem.uiowa.edu/faculty/weisman/index.htm

David Pedersen | EurekAlert!
Further information:
http://www.uiowa.edu/
http://www.biochem.uiowa.edu/faculty/weisman/index.htm

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Taming 'wild' electrons in graphene

23.10.2017 | Physics and Astronomy

Mountain glaciers shrinking across the West

23.10.2017 | Earth Sciences

Scientists track ovarian cancers to site of origin: Fallopian tubes

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>