Ion concentrations in microdomains

There are many unresolved questions in human biology. One of them is the regulation of the processes that takes place very close to the membrane.

The plasma membrane that surrounds the cell consists of a complex mixture of phospholipids, proteins and other molecules. The plasma membrane is packed with ion channels and ion transporters which regulate the ion gradients and the intracellular concentrations. Proteins that form the cell skeleton and control shape changes are also anchored in the plasma membrane.

Changes in the conformation and activity of these proteins are often regulated by Ca2+, however, in vitro studies often show that Ca2+ concentrations of 10-100 µM are required whereas Ca2+ in the bulk cytosol is between 10 nM - 1 µM. There is a huge gap between these numbers, which often is unexplained. Recent studies have shown that very high concentrations of e.g. Ca2+ can be found in microdomains close to the cell membrane.

My research is focused on the ion concentrations in microdomains close to the cell membrane and how they affect the cell and the entire organism. I focus on two systems namely reabsorption in the proximal tubuli in the kidney and formation of Ca2+ microdomains in endothelial and smooth muscle cells in the vessels.

Get to know more about the research area by contacting Jens Christian Brasen.