Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Understanding Night Blindness and Calcium

Congenital stationary night blindness, an inherited condition that affects one’s ability to see in the dark, is caused by a mutation in a calcium channel protein that shuttles calcium into and out of cells.

Now, researchers at the Johns Hopkins University School of Medicine have teased apart the molecular mechanism behind this mutation, uncovering a more general principle of how cells control calcium levels.

The discovery, published in the Feb. 18 issue of Nature, could have implications for several other conditions, including neurodegenerative diseases such as schizophrenia and Alzheimer’s, Parkinson’s and Huntington’s diseases.

“Calcium is so crucial for normal functions like heart contraction, insulin control and brain function,” says David Yue, M.D., Ph.D., a professor of biomedical engineering and director of the Calcium Signals Lab at Hopkins. “If calcium levels are off at any time, disease can ensue. Our new approach, watching calcium channels in action in living cells, allowed us to tease apart how they behave and how they’re controlled and find a new module that could be targeted for drug design.”

The aberrant calcium channel protein that causes this type of night blindness is missing the tail end of the protein. Yue’s team compared the ability of this protein to full length versions by examining how well they can maintain electrical current in cells. Normal channels show a decrease in current with an increase in calcium levels. “We and others initially believed that the missing piece of the protein might behave to simply switch off the ability of elevated intracellular calcium to inhibit this current,” says Yue. “Without this module, there’s no way to down-regulate the calcium entering through these channels.”

Yue’s team found out, however, that in reality, this module functions in a far richer and nuanced manner. Calcium channels are known to be controlled by the protein CaM, which senses and binds to calcium, whereupon CaM binds to channels in a manner that inhibits their calcium transport function. To figure out how the tail module works in conjunction with CaM to control the calcium channel, the team used a molecular optical sensor tool that enabled them to see in live cells different levels of CaM, a controller of the channel protein. When CaM is abundant, the sensor glows cyan; when CaM is low, the sensor glows yellow.

The researchers found that the tail module doesn’t simply turn off channel sensitivity to calcium; rather, the module smoothly retunes how sensitive channels are to CaM, and in turn how sensitive the transport function of channels is to intracellular calcium. In all, the tail module smoothly adjusts how much calcium enters cells. This manner of adjustment “may bear on many neurodegenerative diseases where calcium is dysregulated,” says Yue.

With the optical sensor, Yue and his team next will examine other types of live cells, including nerve and heart cells, to measure whether changes in calcium channel behavior can lead to disease-like states.

This study was funded by the National Institute of Mental Health, the National Heart, Lung and Blood Institute and the National Institute on Deafness and Other Communication Disorders.

Authors on the paper are Xiaodong Liu, Philemon Yang, Wanjun Yang and David Yue, all of Johns Hopkins.

On the Web:
Calcium Signals Lab
Biomedical Engineering at Johns Hopkins
Faculty of 1000 Biology
Science Signaling;3/110/ec62

Audrey Huang | Newswise Science News
Further information:

More articles from Health and Medicine:

nachricht Advanced analysis of brain structure shape may track progression to Alzheimer's disease
26.10.2016 | Massachusetts General Hospital

nachricht Indian roadside refuse fires produce toxic rainbow
26.10.2016 | Duke University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>