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 Turning carbon dioxide into liquid fuel
06.08.2020 | DOE/Argonne National Laboratory

nachricht Tellurium makes the difference
06.08.2020 | Friedrich-Schiller-Universität Jena

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: ScanCut project completed: laser cutting enables more intricate plug connector designs

Scientists at the Fraunhofer Institute for Laser Technology ILT have come up with a striking new addition to contact stamping technologies in the ERDF research project ScanCut. In collaboration with industry partners from North Rhine-Westphalia, the Aachen-based team of researchers developed a hybrid manufacturing process for the laser cutting of thin-walled metal strips. This new process makes it possible to fabricate even the tiniest details of contact parts in an eco-friendly, high-precision and efficient manner.

Plug connectors are tiny and, at first glance, unremarkable – yet modern vehicles would be unable to function without them. Several thousand plug connectors...

Im Focus: New Strategy Against Osteoporosis

An international research team has found a new approach that may be able to reduce bone loss in osteoporosis and maintain bone health.

Osteoporosis is the most common age-related bone disease which affects hundreds of millions of individuals worldwide. It is estimated that one in three women...

Im Focus: AI & single-cell genomics

New software predicts cell fate

Traditional single-cell sequencing methods help to reveal insights about cellular differences and functions - but they do this with static snapshots only...

Im Focus: TU Graz Researchers synthesize nanoparticles tailored for special applications

“Core-shell” clusters pave the way for new efficient nanomaterials that make catalysts, magnetic and laser sensors or measuring devices for detecting electromagnetic radiation more efficient.

Whether in innovative high-tech materials, more powerful computer chips, pharmaceuticals or in the field of renewable energies, nanoparticles – smallest...

Im Focus: Tailored light inspired by nature

An international research team with Prof. Cornelia Denz from the Institute of Applied Physics at the University of Münster develop for the first time light fields using caustics that do not change during propagation. With the new method, the physicists cleverly exploit light structures that can be seen in rainbows or when light is transmitted through drinking glasses.

Modern applications as high resolution microsopy or micro- or nanoscale material processing require customized laser beams that do not change during...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“Conference on Laser Polishing – LaP 2020”: The final touches for surfaces

23.07.2020 | Event News

Conference radar for cybersecurity

21.07.2020 | Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

 
Latest News

Rare Earth Elements in Norwegian Fjords?

06.08.2020 | Earth Sciences

Anode material for safe batteries with a long cycle life

06.08.2020 | Power and Electrical Engineering

Turning carbon dioxide into liquid fuel

06.08.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>