Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Scientists identify molecular cause for one form of deafness

Abstract:
Scientists exploring the physics of hearing have found an underlying molecular cause for one form of deafness, and a conceptual connection between deafness and the organization of liquid crystals, which are used in flat-panel displays.

Scientists identify molecular cause for one form of deafness

Champaign, IL | Posted on February 5th, 2007

Within the cochlea of the inner ear, sound waves cause the basilar
membrane to vibrate. These vibrations stimulate hair cells, which
then trigger nerve impulses that are transmitted to the brain.

Researchers have now learned that mutations in a protein called espin
can cause floppiness in tiny bundles of protein filaments within the
hair cells, impairing the passage of vibrations and resulting in
deafness.

Filamentous actin (F-actin) is a rod-like protein that provides
structural framework in living cells. F-actin is organized into
bundles by espin, a linker protein found in sensory cells, including
cochlear hair cells. Genetic mutations in espin's F-actin binding
sites are linked to deafness in mice and humans.

"We found the structure of the bundles changes dramatically when
normal espin is replaced with espin mutants that cause deafness,"
said Gerard Wong, a professor of materials science and engineering,
of physics, and of bioengineering at the University of Illinois at
Urbana-Champaign.

"The interior structure of the bundles changes from a rigid,
hexagonal array of uniformly twisted filaments, to a liquid
crystalline arrangement of filaments," Wong said. "Because the new
organization causes the bundles to be more than a thousand times
floppier, they cannot respond to sound in the same way. The rigidity
of these bundles is essential for hearing."

Wong and his co-authors - Illinois postdoctoral research associate
Kirstin Purdy and Northwestern University professor of cell and
molecular biology James R. Bartles - report their findings in a paper
accepted for publication in the journal Physical Review Letters, and
posted on its Web site.

High-resolution X-ray diffraction experiments, performed by Purdy at
the Advanced Photon Source and at the Stanford Synchrotron Radiation
Laboratory, allowed the researchers to solve the structure of various
espin-actin bundles.

"As the ability of espin to cross-link F-actin is decreased by using
genetically modified 'deafness' mutants with progressively more
damaged actin binding sites, the structure changes from a
well-ordered crystalline array of filaments to a nematic, liquid
crystal-like state," said Wong, who also is a researcher at the
Frederick Seitz Materials Research Laboratory on campus and at the
university's Beckman Institute for Advanced Science and Technology.

In the liquid crystalline state, the bundles maintain their
orientation order - that is, they point roughly along the same
direction - but lose their positional order. These nematic liquid
crystals are commonly used in watch displays and laptop displays.

Wong and his colleagues also found that a mixture of mutant espin and
normal espin would prevent the structural transition from occurring.
If gene expression could turn on the production of just a fraction of
normal espin linkers, a kind of rescue attempt at restoring hearing
could, in principle, be made.

"We have identified the underlying molecular cause for one form of
deafness, and we have identified a mechanism to potentially 'rescue'
this particular kind of pathology," Wong said. "Even so, this is
really the first step. This work has relevance to not just human
hearing, but also to artificial sensors."

The U.S. Department of Energy, National Institutes of Health and
National Science Foundation funded the work.

####

About University of Illinois
At Illinois, research shapes the campus identity, stimulates classroom instruction and serves as a springboard for public engagement activities throughout the world. Opportunities abound for graduate students to develop independent projects and launch their own careers as researchers while working alongside faculty and assisting in their research. Illinois continues its long tradition of groundbreaking accomplishments with remarkable new discoveries and achievements that inspire and enrich the lives of people around the world.

For more information, please click here

Contacts:
Gerard Wong
217-265-5254

Copyright © University of Illinois

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Discoveries

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

New Biosensor Produced in Iran to Detect Effective Drugs in Cancer Treatment July 4th, 2015

Clues to inner atomic life from subtle light-emission shifts: Hyperfine structure of light absorption by short-lived cadmium atom isotopes reveals characteristics of the nucleus that matter for high precision detection methods July 3rd, 2015

Groundbreaking research to help control liquids at micro and nano scales July 3rd, 2015

Announcements

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

New Biosensor Produced in Iran to Detect Effective Drugs in Cancer Treatment July 4th, 2015

Clues to inner atomic life from subtle light-emission shifts: Hyperfine structure of light absorption by short-lived cadmium atom isotopes reveals characteristics of the nucleus that matter for high precision detection methods July 3rd, 2015

Pioneering Southampton scientist awarded prestigious physics medal July 3rd, 2015

Human Interest/Art

Renishaw's inVia confocal Raman microscope system is being used in conservation activities at the Rijksmuseum in Amsterdam, the Netherlands June 16th, 2015

New sensing tech could help detect diseases, fraudulent art, chemical weapons June 1st, 2015

INSIDDE: Uncovering the real history of art using a graphene scanner May 21st, 2015

Winner Announced for NNI’s First ‘EnvisioNano’ Nanotechnology Image Contest May 6th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project