Molecular cloning of ion transporters: potential clinical implications

The ion transporters are a group of integral membrane proteins which, like enzymes, can be regulated at multiple levels. Understanding of function and regulation of these proteins has been greatly facilitated by the knowledge of their molecular structures. In this article, we discuss the various approaches used in the cloning of these proteins. We then focus on genetic disorders known to be caused by abnormal structure of the transporter protein including cystic fibrosis, generalized myotonia and myotonia congenita, hyperkalemic periodic paralysis, hereditary ovalocytosis, hereditary spherocytosis and glucose malabsorption. Renal disorders thought, but not proved, to be due to abnormal transporter structure/function are briefly mentioned.