How many Orai's does it take to make a CRAC channel?

Sci Rep

Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642, USA.

Published: October 2013

CRAC (Calcium Release-Activated Calcium) channels represent the primary pathway for so-called "store-operated calcium entry" - the cellular entry of calcium induced by depletion of intracellular calcium stores. These channels play a key role in diverse cellular activities, most noticeably in the differentiation and activation of Tcells, and in the response of mast cells to inflammatory signals. CRAC channels are formed by members of the recently discovered Orai protein family, with previous studies indicating that the functional channel is formed by a tetramer of Orai subunits. However, a recent report has shown that crystals obtained from the purified Drosophila Orai protein display a hexameric channel structure. Here, by comparing the biophysical properties of concatenated hexameric and tetrameric human Orai1 channels expressed in HEK293 cells, we show that the tetrameric channel displays the highly calcium-selective conductance properties consistent with endogenous CRAC channels, whilst the hexameric construct forms an essentially non-selective cation channel.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3675454PMC
http://dx.doi.org/10.1038/srep01961DOI Listing

Publication Analysis

Top Keywords

crac channels
8
orai protein
8
calcium
5
channels
5
orai's crac
4
crac channel?
4
channel? crac
4
crac calcium
4
calcium release-activated
4
release-activated calcium
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!