Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Like Eavesdropping at a Party

01.08.2008
Scientists Discover How a Tiny Protein Senses All the Communications in a Cell

Cells rely on calcium as a universal means of communication. For example, a sudden rush of calcium can trigger nerve cells to convey thoughts in the brain or cause a heart cell to beat.

A longstanding mystery has been how cells and molecules manage to appropriately sense and respond to the variety of calcium fluctuations within cells.

Reporting in the June 27 issue of Cell, a team of biomedical engineers at the Johns Hopkins School of Medicine has discovered how the calcium sensor protein calmodulin can gauge both the local flow of calcium, in through the closest channel, as well as the global calcium flow entering the many channels across the entire cell.

... more about:
»Cell »Yue »calmodulin »lobe

“It’s like being at a cocktail party where the easiest person to listen to is the one closest to you, but we all have the ability to keep an ear out for other interesting conversations going on throughout the room,” says David Yue, M.D., Ph.D., a professor of biomedical engineering at Hopkins. “It turns out that calmodulin is doing a similar thing, sensing the calcium coming through the closest channel through one ear while the other ear ‘listens’ to the calcium coming through distant channels across the cell.”

Normally, calmodulin is positioned right near each calcium channel. Several years ago, scientists discovered that calmodulin somehow can switch its sensory focus between local calcium and global calcium entering the cell through channels at a distance.

The calmodulin protein, explains Yue, is made of two ball-like lobes, and it’s these two lobes that act as the different calcium-sensing “ears.” The C lobe listens locally and the N lobe listens globally, across the whole cell. To figure out how calmodulin’s two lobes can sense different sources of calcium, the team took a two-pronged approach.

First, they used computers to perform mathematical simulations that tested different potential calcium detection mechanisms of the calmodulin lobes. Others have shown that the C lobe of calmodulin hangs onto calcium for a long time, whereas the N lobe lets go rapidly. Their simulations suggested that these slight differences in calcium holding time might play a role in calmodulin’s ability to sense both local and global calcium levels. “Once a local calcium ion sticks to the C lobe, it seldom lets go, and so the local calcium dominates,” says Yue.

By contrast, the N lobe would rapidly let go of calcium and then be empty and available to bind calcium entering the cell from distant calcium channels, allowing reception of global calcium. Similar to the cocktail party, it’s easiest to catch other conversations during the pauses in your own conversation.

The research team then verified their mathematical predictions by testing real calmodulin proteins attached to calcium channels. Using a new approach, they precisely controlled calcium pulses through single calcium channels and watched how calmodulin responded. They were able to confirm the mathematical models.

Understanding the language of calcium is critical for understanding how cells communicate, says Yue, and also important for understanding neural diseases. For instance, early antipsychotic drugs may work by blocking calmodulin action. “Now that we are learning how these drugs actually work,” Yue says, “we can contribute our new understanding of calmodulin to the design of next-generation drugs with greater potency and fewer side effects.”

The research was funded by the National Institutes of Health.

Authors on the paper are Michael Tadross, Ivy Dick and Yue, all of Hopkins.

Audrey Huang | Newswise Science News
Further information:
http://www.jhmi.edu

Further reports about: Cell Yue calmodulin lobe

More articles from Life Sciences:

nachricht 'Y' a protein unicorn might matter in glaucoma
23.10.2017 | Georgia Institute of Technology

nachricht Microfluidics probe 'cholesterol' of the oil industry
23.10.2017 | Rice University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>