4O9B

The Structure of CC1-IH in human STIM1.

Replaces:  4IOZ

Summary for 4O9B

• Entry DOI: 10.2210/pdb4o9b/pdb
• Descriptor: Stromal interaction molecule 1, CADMIUM ION (3 entities in total)
• Functional Keywords: signaling protein, structural genomics, nppsfa, national project on protein structural and functional analyses, alpha helices, signaling
• Biological source: Homo sapiens (human)
• Cellular location: Cell membrane; Single-pass type I membrane protein: Q13586
• Total number of polymer chains: 4
• Total formula weight: 50537.71

Authors

Cui, B.,Yang, X.,Li, S.,Shen, Y. (deposition date: 2014-01-02, release date: 2014-01-15, Last modification date: 2024-02-28)

Primary citation

Cui, B.,Yang, X.,Li, S.,Lin, Z.,Wang, Z.,Dong, C.,Shen, Y.
The inhibitory helix controls the intramolecular conformational switching of the C-terminus of STIM1.
Plos One, 8:e74735-e74735, 2013

PubMed Abstract: Store-operated Ca(2+) entry (SOCE) is a critical Ca(2+) signaling pathway in many cell types. After sensing Ca(2+) store depletion in the endoplasmic reticulum (ER) lumen, STIM1 (STromal Interaction Molecule 1) oligomerizes and then interacts with and activates the Orai1 calcium channel. Our previous research has demonstrated that the inhibitory helix (IH) adjacent to the first coiled-coil region (CC1) of STIM1 may keep the whole C-terminus of STIM1 in an inactive state. However, the specific conformational change of CC1-IH that drives the transition of STIM1 from the resting state to the active state remains elusive. Herein, we report the structural analysis of CC1-IH, which revealed that the entire CC1-IH molecule forms a very long helix. Structural and biochemical analyses indicated that IH, and not the CC1 region, contributes to the oligomerization of STIM1. Small-angle X-ray scattering (SAXS) analysis suggested that the C-terminus of STIM1 including the IH region displays a collapsed conformation, whereas the construct without the IH region has an extended conformation. These two conformations may correspond to the conformational states of the C-terminus of STIM1 before and after activation. Taken together, our results provide direct biochemical evidence that the IH region controls the conformational switching of the C-terminus of STIM1.

PubMed: 24069340
DOI: 10.1371/journal.pone.0074735

Experimental method

X-RAY DIFFRACTION (2.604 Å)