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

More articles from Life Sciences:

nachricht World’s Largest Study on Allergic Rhinitis Reveals new Risk Genes
17.07.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Plant mothers talk to their embryos via the hormone auxin
17.07.2018 | Institute of Science and Technology Austria

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

World’s Largest Study on Allergic Rhinitis Reveals new Risk Genes

17.07.2018 | Life Sciences

Electronic stickers to streamline large-scale 'internet of things'

17.07.2018 | Information Technology

Behavior-influencing policies are critical for mass market success of low carbon vehicles

17.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>