Structural Biology Architecture of a CRAC

Valda Vinson

Science, AAAS, Washington, DC 20005, USA

The calcium release–activated calcium (CRAC) channel generates intracellular calcium signals in response to depletion of calcium from the endoplasmic reticulum. Hou et al. report a high-resolution crystal structure of Orai, the CRAC channel pore from Drosophila melanogaster. Six Orai subunits surround a central pore that extends into the cytosol. The pore is in a closed conformation that is stabilized by anions binding to a basic region near the intracellular side. A ring of glutamates on the extracellular side form a selectivity filter. The channel architecture allows calcium permeation while regulating the flow to prevent overloading the cell with calcium.

X. Hou, L. Pedi, M. M. Diver, S. B. Long, Crystal structure of the calcium release–activated calcium channel Orai. Science 338, 1308–1313 (2012). [Abstract] [Full Text]

The editors suggest the following Related Resources on Science sites:

In Science Signaling

RESEARCH ARTICLES
Calcium Signaling
Activation of STIM1-Orai1 Involves an Intramolecular Switching Mechanism

Marek K. Korzeniowski, Isabel Martín Manjarrés, Peter Varnai, and Tamas Balla (16 November 2010)
Sci. Signal. 3 (148), ra82. [DOI: 10.1126/scisignal.2001122]
 |  Editor's Summary »  |  Abstract »  |  Full Text »  |  PDF »  |  Supplementary Materials »

RESEARCH ARTICLES
Immunology
Differential Redox Regulation of ORAI Ion Channels: A Mechanism to Tune Cellular Calcium Signaling

Ivan Bogeski, Carsten Kummerow, Dalia Al-Ansary, Eva C. Schwarz, Richard Koehler, Daisuke Kozai, Nobuaki Takahashi, Christine Peinelt, Desiree Griesemer, Monika Bozem, Yasuo Mori, Markus Hoth, and Barbara A. Niemeyer (30 March 2010)
Sci. Signal. 3 (115), ra24. [DOI: 10.1126/scisignal.2000672]
 |  Editor's Summary »  |  Abstract »  |  Full Text »  |  PDF »  |  Supplementary Materials »

EDITORS' CHOICE
Channels
Identifying the CRAC Channel

Elizabeth M. Adler (19 September 2006)
Sci. STKE 2006 (353), tw325. [DOI: 10.1126/stke.3532006tw325]
 |  Abstract »