Calcium signals control almost every activity in the human body, from fertilization to cell death and everything between, including every beat of the heart. The researchers have found that just 2-3 calcium channels, from among the many thousands present on the surface of a cell, are responsible for much of the calcium signal that regulates the activity of immune cells. The 2-3 channels are formed by inositol trisphosphate (IP3) receptors on the membrane that surrounds the cell. Despite being the cellular equivalent of a needle in a haystack, the team discovered that these 2-3 channels make a substantial contribution to calcium signalling.
Cells expressing inositol triphosphate receptors with an engineered binding site stained with snake venom
The membranes of cells are like dams holding back a flood of calcium. Channels within these membranes are the sluice gates that cells regulate to allow controlled entry of calcium. Too much calcium and the cell dies. But just as the water from a dam may be directed via the sluice gates to a fish ladder or a generator, then so the calcium passing through channels can be sent to different intracellular proteins to bring about different cellular responses. In this way, the same intracellular messenger, calcium, can be used to control all sorts of things without confusing the cell. The new research shows that IP3 channels, originally thought to be found only in membranes within the cell, such as the endoplasmic reticulum, are also found in its external membrane.
The researchers believe that this new role for IP3 receptors on the cell membrane, additional to their established role within the cell, paves the way to addressing the mechanisms that allow calcium to so effectively regulate so many cellular activities. Such an understanding could give a better idea of processes governing cell growth and development and could eventually lead to more sophisticated drug targeting.
The scientists built on work from others that aimed to develop new treatments for venomous snake-bites, by making short peptides that specifically bind to the venom. Using molecular biological methods they incorporated the same peptide into the IP3 receptor and demonstrated that it was now regulated by the snake venom.
Professor Colin Taylor led the research at the University of Cambridge’s Department of Pharmacology. He said: “Every schoolchild knows that calcium is the element that forms our teeth and bones, but it also has this key and very dynamic role as a controlling signal within every cell of the human body. Everything from the beating of the heart to cell division and cell death is controlled by calcium. The key question is how cells manage to use calcium to control so much without getting confused. It’s rather like trying to listen in to just one conversation at a noisy party. Our research brings us another step forward to understanding how cells regulate the inward flow of calcium. That is important, because when we use calcium in this way as a signal, we invite the enemy within and unless we keep it under very tight control the calcium will kill the cell.
“One of the more intriguing features of the work is the reliability with which these cells incorporate such small numbers of IP3 receptors into the membrane. Even if we force the cells to produce more IP3 receptors, they still place just 2-3 of them in the plasma membrane, and they always seem to get it right. What we really don’t understand is how they do it. The challenge now is to find out.”
The research published in Science is based on work funded by BBSRC and the Wellcome Trust.
Matt Goode | alfa
Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory
How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy