A research project conducted by Dr Raphael Courjaret, research associate in Physiology and Biophysics, and Dr Khaled Machaca, associate dean for Research, has shed new light on the complex role played by calcium ions (Ca2 ), which at the cellular level serve as messengers, ferrying information to different parts of the cell to facilitate key biochemical processes such as fertilisation, muscle contraction, transmission of nervous signals and blood clotting.

The research, which used advanced laser microscopy and electrophysiology techniques to reveal a novel pathway for calcium signaling at the intracellular level, has been published in the prestigious biomedical journal, Nature Communications.

“Calcium is an intracellular messenger that encodes information from the environment into a cellular response. It tells the cell when to move, divide or even die. In other words, calcium converts information into a new language that the cell can understand,” Dr Courjaret explained.

It has long been known that calcium plays a role as a messenger within cells, and that calcium ions can enter cells through membrane proteins known as channels; it is also well known that calcium is able to serve as an intracellular messenger by signaling locally in close proximity to these channels, as well as globally if the ions spread throughout the whole cell.

The new work by Dr Courjaret and Dr Machaca has defined a novel calcium signalling pathway between these two spatial extremes that they call “mid-range calcium signalling”.

“What we were able to show was a level of sophistication in the way calcium ions are used to distribute information around the cell, which was not previously understood. We found mechanisms that allow calcium ions to travel within an intracellular structure called the endoplasmic reticulum, which acts as a communication hub to distribute Ca2  to a distant effector,” Dr Courjaret said.

“Given the ubiquitous nature of Ca2  signaling, our findings are likely to have broad implications on many physiological and pathological processes,” Dr Machaca said.

The paper, titled Mid-range Ca2  signaling mediated by functional coupling between store-operated Ca2  entry and IP3-dependent Ca2  release, was published on May 28.

The work described in the paper was funded by a grant from the National Priorities Research Programme of the Qatar National Research Fund and by the Biomedical Research Programme of Qatar Foundation, which supports the research effort at WCMC-Q.