Researchers at the University of Pennsylvania School of Medicine have now identified the mechanism by which a single amino acid change can disrupt the normal functioning of one of the critical components of that physiology -- a molecular motor protein called myo1c, which resides in the cochlea of the inner ear.
The mutation (called R156W), was first identified in an individual suffering from cochlear hearing loss, and it affects the way the myo1c protein interacts with proteins known as actin filaments, another crucial component of the sensory apparatus of the inner ear. This interaction is essential for normal hearing, and scientists have already traced other causes of hearing loss to previously known mutations that interrupt it.
Now Michael Greenberg and his colleagues at UPenn have examined the biochemical and mechanical properties of the mutant myosin protein. Comparing constructs of the normal, "wild-type" protein to the R156W mutant, they examined the two proteins' kinetics and motility and discovered the mutant has a reduced sensitivity to mechanical loads and a lower duty ratio, meaning it spends less time attached to actin filaments.
Though the cochlear cell myo1c defects are associated with hearing loss, how this mutation causes the disease is still a mystery. The exact molecular role of myo1c is hazy, although it has been linked to several important cellular processes including hearing and insulin stimulated glucose uptake within cells. Understanding the defects caused by the R156 mutation could help to solve the puzzle.
“R156 is a highly conserved residue throughout the myosin superfamily. The fact that mutation of this residue affects the myosin duty ratio and strain sensitivity may very well be applicable in other myosins as well. In the long term, we hope to gain greater insight into the mechanism of myosin strain sensitivity and its role in mechanotransduction,” says Greenberg.
The group’s research is funded by the National Institutes of Health and the American Heart Association.
MORE MEETING INFORMATION
Each year, the Biophysical Society Annual Meeting brings together more than 6,000 scientists and hosts more than 4,000 poster presentations, 200 exhibits, and more than 20 symposia. The largest meeting of its type in the world, the Biophysical Society Annual Meeting retains its small-meeting flavor through its subgroup meetings, platform sessions, social activities, and committee programs.QUICK LINKS
A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences