Please use this identifier to cite or link to this item:
|Title:||Ca2+ regulation in the Na+/Ca2+ exchanger involves two markedly different Ca2+ sensors.|
|Citation:||MOL CELL, 2006, 22 (1), pp. 15-25|
|Abstract:||The plasma membrane Na+/Ca2+ exchanger (NCX) is almost certainly the major Ca2+ extrusion mechanism in cardiac myocytes. Binding of Na+ and Ca2+ ions to its large cytosolic loop regulates ion transport of the exchanger. We determined the solution structures of two Ca2+ binding domains (CBD1 and CBD2) that, together with an alpha-catenin-like domain (CLD), form the regulatory exchanger loop. CBD1 and CBD2 are very similar in the Ca2+ bound state and describe the Calx-beta motif. Strikingly, in the absence of Ca2+, the upper half of CBD1 unfolds while CBD2 maintains its structural integrity. Together with a 7-fold higher affinity for Ca2+, this suggests that CBD1 is the primary Ca2+ sensor. Specific point mutations in either domain largely allow the interchange of their functionality and uncover the mechanism underlying Ca2+ sensing in NCX.|
|Appears in Collections:||Published Articles, Dept. of Biochemistry|
Files in This Item:
There are no files associated with this item.
Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.