A single lysine in the N-terminal region of store-operated channels is critical for STIM1-mediated gating.

Lis, Annette; Zierler, Susanna; Peinelt, Christine; Fleig, Andrea; Penner, Reinhold (2010). A single lysine in the N-terminal region of store-operated channels is critical for STIM1-mediated gating. Journal of general physiology, 136(6), pp. 673-686. Rockefeller University Press 10.1085/jgp.201010484

Preview

Text A single Iysine in the.pdf - Published Version Available under License Creative Commons: Attribution-Noncommercial-Share Alike (CC-BY-NC-SA). Download (2MB) | Preview

Store-operated Ca(2+) entry is controlled by the interaction of stromal interaction molecules (STIMs) acting as endoplasmic reticulum ER Ca(2+) sensors with calcium release-activated calcium (CRAC) channels (CRACM1/2/3 or Orai1/2/3) in the plasma membrane. Here, we report structural requirements of STIM1-mediated activation of CRACM1 and CRACM3 using truncations, point mutations, and CRACM1/CRACM3 chimeras. In accordance with previous studies, truncating the N-terminal region of CRACM1 or CRACM3 revealed a 20-amino acid stretch close to the plasma membrane important for channel gating. Exchanging the N-terminal region of CRACM3 with that of CRACM1 (CRACM3-N(M1)) results in accelerated kinetics and enhanced current amplitudes. Conversely, transplanting the N-terminal region of CRACM3 into CRACM1 (CRACM1-N(M3)) leads to severely reduced store-operated currents. Highly conserved amino acids (K85 in CRACM1 and K60 in CRACM3) in the N-terminal region close to the first transmembrane domain are crucial for STIM1-dependent gating of CRAC channels. Single-point mutations of this residue (K85E and K60E) eliminate store-operated currents induced by inositol 1,4,5-trisphosphate and reduce store-independent gating by 2-aminoethoxydiphenyl borate. However, short fragments of these mutant channels are still able to communicate with the CRAC-activating domain of STIM1. Collectively, these findings identify a single amino acid in the N terminus of CRAC channels as a critical element for store-operated gating of CRAC channels.

Interest & Impact

Downloads

165 since deposited on 14 Jun 2018
21 in the past 12 months

Citations

5 Citations in Web of Science ®
6 Citations in Scopus

Search

in Google Scholar™

Services

Actions (login required)

Edit item

Actions (login required)

Edit item