Inositol 1, 4, 5-trisphosphate receptor interacts with the SNARE domain of syntaxin 1B

• Published in: The journal of physiological sciences Vol. 61; no. 3; pp. 221 - 229
• Main Authors: Tanaka, Sayaka, Kabayama, Hiroyuki, Enomoto, Masahiro, Saito, Nobuhito, Mikoshiba, Katsuhiko
• Format: Journal Article
• Language: English
• Published: Japan Springer Japan 01.05.2011
• Subjects: Animals; Binding Sites; Calcium - metabolism; Cell Line; Inositol 1,4,5-Trisphosphate Receptors - chemistry; Inositol 1,4,5-Trisphosphate Receptors - metabolism; Ion Channel Gating - physiology; Ion Channels - metabolism; Mice; Mutation; Original Paper; PC12 Cells; Protein Binding; Protein Structure, Tertiary; Rats; SNARE Proteins - chemistry; SNARE Proteins - metabolism; Syntaxin 1 - chemistry; Syntaxin 1 - metabolism
• ISSN: 1880-6546; 1880-6562
• DOI: 10.1007/s12576-011-0140-4

Inositol 1, 4, 5-trisphosphate receptors (IP(3)Rs) are intracellular ligand-gated Ca(2+) channels that mediate Ca(2+) release from the endoplasmic reticulum (ER) into the cytosol and function in diverse cellular processes including fertilization, muscle contraction, apoptosis, secretion, and synaptic plasticity. The Ca(2+) release activity of IP(3)Rs is tightly regulated by many factors including IP(3)R-binding proteins. We show that IP(3)Rs interact with syntaxin 1 (Syx1), a membrane trafficking protein that regulates various plasma-membrane ion channels including N-, P/Q, and L-type voltage-gated Ca(2+) channels, voltage-gated potassium channels, and an epithelial sodium channel. We found that a SNARE-domain of Syx1B, one of the two Syx1 isoforms, directly interacted with the type1 IP(3)R (IP(3)R1) internal coupling domain, a known modulator for channel opening. These results indicate that Syx1B is an IP(3)R-interacting protein and that its interaction may play a crucial role in regulating the channel activity of IP(3)Rs in Syx1B-expressing cells.