Editors' ChoiceCell Biology

From Klotho to Calcium

Science's STKE  19 Jun 2007:
Vol. 2007, Issue 391, pp. tw220
DOI: 10.1126/stke.3912007tw220

Klotho, a membrane protein with similarity to glycosidases, has been proposed to modify sugar residues on a TRP channel, to interact with the receptor for fibroblast growth factor 23, and to extend life span when overexpressed. Now Imura et al. report that α-Klotho interacts with the α subunit of the Na+,K+-adenosine triphosphatase (Na+,K+-ATPase) in mouse cells. The amount of Na+,K+-ATPase at the plasma membrane appeared to decrease in cells exposed to high concentrations of Ca2+, a response that was blunted in cells lacking α-Klotho. The concentration of Ca2+ in cerebrospinal fluid of mice lacking α-Klotho was slightly lower than that in wild-type animals. Thus, α-Klotho may function in the control of Ca2+ concentrations by influencing the abundance of the Na+,K+-ATPase transporter in plasma membranes.

A. Imura, Y. Tsuji, M. Murata, R. Maeda, K. Kubota, A. Iwano, C. Obuse, K. Togashi, M. Tominaga, N. Kita, K. Tomiyama, J. Iijima, Y. Nabeshima, M. Fujioka, R. Asato, S. Tanaka, K. Kojima, J. Ito, K. Nozaki, N. Hashimoto, T. Ito, T. Nishio, T. Uchiyama, T. Fujimori, Y. Nabeshima, α-Klotho as a regulator of calcium homeostasis. Science 316, 1615-1618 (2007). [Abstract] [Full Text]