Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Well-known protein reveals new tricks

07.09.2012
UCSF study shows clathrin protein moonlights, playing key role in cell division

A protein called "clathrin," which is found in every human cell and plays a critical role in transporting materials within them, also plays a key role in cell division, according to new research at the University of California, San Francisco.

The discovery, featured on the cover of the Journal of Cell Biology in August, sheds light on the process of cell division and provides a new angle for understanding cancer. Without clathrin, cells divide erratically and unevenly—a phenomenon that is one of the hallmarks of the disease.

"Clathrin is doing more than we thought it was doing," said Frances Brodsky, DPhil, who led the research. Brodsky is a professor in the UCSF Department of Bioengineering and Therapeutic Sciences, a joint department of the Schools of Pharmacy and Medicine, and she holds joint appointments in Microbiology and Immunology, as well as Pharmaceutical Chemistry.

A Protein Essential for Transportation in More Than One Route

Akin to a three-pronged building block in a child's construction set, clathrin can provide links to create larger complexes. When lots of these proteins are assembled together, they can form tough little cages into which cells packs many of their essential biological molecules—hormones, neurotransmitters, membrane proteins and other payloads that need to be transported throughout the cell.

Once thought to be solely involved in transport inside cells, scientists have uncovered more and more of the protein's hidden functions in the last half-dozen years, including some roles it plays in cell division.

For instance, they learned several years ago about its role in the function of "spindles." Normally when a cell divides, it forms a spindle by laying down tracks of structural proteins, and uses them as scaffolding to separate the cell's DNA (in the form of chromosomes) into two equal collections—one identical set of DNA for each of the new daughter cells. Scientists found that clathrin is involved in stabilizing these spindles.

Now, however, Brodsky and her colleagues have shown that clathrin does even more. They deleted clathrin from cells using a technique called RNA interference, which involves infusing in small genetic fragments that block the cell from making the clathrin. Doing so, Brodsky and her colleagues showed that clathrin stabilizes the structures in dividing cells known as centrosomes.

Tagged with fluorescent chemicals and viewed under a microscope, the centrosomes within a cell that is about to divide look like two glowing eyes peering through the dark. But without clathrin, the team determined, the eyes increase in number.

Brodsky and her colleagues traced this effect to a protein complex formed by one particular component of clathrin called CHC17, which directly stabilizes the centrosome and helps it mature. Deleting CHC17 or chemically inactivating it, led to cells with a strange appearance. These cells contained multiple, fragmented centrosomes instead of the normal two and built abnormal spindles.

This discovery may reveal pathways towards abnormalities of chromosome segregation associated with cancer, said Brodsky.

The article, "Clathrin promotes centrosome integrity in early mitosis through stabilization of centrosomal ch-TOG" by Amy B. Foraker, Stéphane M. Camus, Timothy M. Evans, Sophia R. Majeed, Chih-Ying Chen, Sabrina B. Taner, Ivan R. Corrêa Jr., Stephen J. Doxsey and Frances M. Brodsky appears in the August 20, 2012 issue of the Journal of Cell Biology. See: http://dx.doi.org/10.1083/jcb.201205116

In addition to the group at UCSF, authors on this study are affiliated with New England Biolabs, Inc., in Ipswich, MA, and the University of Massachusetts Medical School in Worcester, MA.

Jason Socrates Bardi | EurekAlert!
Further information:
http://www.ucsf.edu

Further reports about: CHC17 DNA UCSF cell death cell division synthetic biology

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

Microscopic trampoline may help create networks of quantum computers

17.07.2018 | Information Technology

In borophene, boundaries are no barrier

17.07.2018 | Materials Sciences

The role of Sodium for the Enhancement of Solar Cells

17.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>