Potassium is the most abundant ion found in mammalian cells and many cell functions are critically dependent on its concentration. Indeed, too much or too little potassium in the blood can cause changes in blood pressure and precipitate life threatening muscle weakness and heart rhythm disturbances. For these reasons, the total amount of potassium in the body and its distribution in and out of cells is very tightly regulated. The kidney is the major organ involved in the long term regulation of total amount of potassium in the body. In many cells, including those of the kidney, potassium is transported via specialized protein structures called ion channels. In the kidney, nothing is known about the structural properties and regulation of these proteins. Using a new and powerful research technique called the Polymerase Chain Reaction (PCR) Dr. Desir and collaboration have been able to isolate parts of six genes which encode potassium channels in the kidney. He now proposes to further characterize these kidney genes using the tools of molecular biology. He will then examine the mechanisms by which these proteins are regulated in the kidney. These studies will make fundamental contributions to our understanding of the physiology and pathophysiology of potassium transport in the kidney.//
