STIM-Orai Channels

STIM-Orai channels have recently been identified as the underlying molecular mechanism of store-operated calcium entry (SOCE). STIM (stromal interaction molecule) proteins are ER Ca2+ sensors. Orai proteins are STIM binding partners that form the channel pore.

Products
Background
Gene Data

Inhibitors

Cat No Product Name / Activity
0431 ML 9 hydrochloride
STIM1-plasma membrane interaction inhibitor. Also MLCK inhibitor
1866 MRS 1845
Potent SOCE inhibitor; blocks capacitative Ca2+ entry
1147 SKF 96365 hydrochloride
STIM1-mediated Ca2+ influx inhibitor
3939 YM 58483
Inhibits CRAC channels

Blockers

Cat No Product Name / Activity
5490 5J 4
CRAC channel blocker; anti-inflammatory

Other

Cat No Product Name / Activity
1224 2-APB
Increases STIM-Orai channel conductivity and reduces selectivity

STIM-Orai channels have recently been identified as the underlying molecular mechanism of store-operated calcium entry (SOCE). SOCE allows rapid Ca2+ efflux from the endoplasmic reticulum (ER), following the emptying of intracellular Ca2+ stores.

STIM (stromal interaction molecule) proteins, STIM1 and STIM2, serve as ER Ca2+ sensors. They contain N'-terminal Ca2+-sensing EF-hand domains and are localized to the tubular ER. Following Ca2+ store depletion, STIMs rapidly cluster and relocalize to the plasma membrane-adjacent ER regions, where they oligomerize and form 'puncta'.

Orai proteins, Orai1, Orai2 and Orai3, are STIM binding partners that form the pore of the channel. Orai proteins are uniformly distributed in the plasma membrane and exist as dimers in the resting state. STIM activation induces tetramerization of Orai proteins and subsequent STIM-Orai colocalization, which forms the active store-operated calcium channel.

STIM-Orai Channel Gene Data

Gene Species Gene Symbol Gene Accession No. Protein Accession No.
STIM1 Human STIM1 NM_003156 Q13586
Mouse Stim1 NM_009287 P70302
Rat Stim1 NM_001108496 P84903
STIM2 Human STIM2 NM_020860 Q9P246
Mouse Stim2 NM_001081103 P83093
Rat Stim2 NM_001105750 XP_223454
Orai1 Human ORAI1 NM_032790 Q96D31
Mouse Orai1 NM_175423 Q8BWG9
Rat Orai1 NM_001013982 Q5M848
Orai2 Human ORAI2 NM_032831 Q96SN7
Mouse Orai2 NM_178751 Q8BH10
Rat Orai2 XM_222288 XP_222288
Orai3 Human ORAI3 NM_152288 Q9BRQ5
Mouse Orai3 NM_198424 Q6P8G8
Rat Orai3 NM_001014024 Q6AXR8