Structural highlights
Function
[CLHM1_CAEEL] Pore-forming subunit of a voltage-gated ion channel. Permeable to monovalent cations, divalent cations and anions with selectivity Ca(2+) > Mg(2+) > Na(+) = K(+) > Cl(-). Acts both as a voltage-gated and calcium-activated ion channel. Required for normal locomotion.[1]
Publication Abstract from PubMed
Calcium homeostasis modulators (CALHMs/CLHMs) comprise a family of pore-forming protein complexes assembling into voltage-gated, Ca(2+) -sensitive, nonselective channels. These complexes contain an ion-conduction pore sufficiently wide to permit the passing of ATP molecules serving as neurotransmitters. While their function and structure information is accumulating, the precise mechanisms of these channel complexes remain to be full understood. Here, we present the structure of the Caenorhabditis elegans CLHM1 channel in its open state solved through single-particle cryo-electron microscopy at 3.7-A resolution. The transmembrane region of the channel structure of the dominant class shows an assembly of 10-fold rotational symmetry in one layer, and its cytoplasmic region is involved in additional twofold symmetrical packing in a tail-to-tail manner. Furthermore, we identified a series of amino acid residues critical for the regulation of CeCLHM1 channel using functional assays, electrophysiological analyses as well as structural-based analysis. Our structure and function analyses provide new insights into the mechanisms of CALHM channels.
Cryo-electron microscopy structure of CLHM1 ion channel from Caenorhabditis elegans.,Yang W, Wang Y, Guo J, He L, Zhou Y, Zheng H, Liu Z, Zhu P, Zhang XC Protein Sci. 2020 Aug;29(8):1803-1815. doi: 10.1002/pro.3904. Epub 2020 Jun 30. PMID:32557855[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Tanis JE, Ma Z, Krajacic P, He L, Foskett JK, Lamitina T. CLHM-1 is a functionally conserved and conditionally toxic Ca2+-permeable ion channel in Caenorhabditis elegans. J Neurosci. 2013 Jul 24;33(30):12275-86. doi: 10.1523/JNEUROSCI.5919-12.2013. PMID:23884934 doi:http://dx.doi.org/10.1523/JNEUROSCI.5919-12.2013
- ↑ Yang W, Wang Y, Guo J, He L, Zhou Y, Zheng H, Liu Z, Zhu P, Zhang XC. Cryo-electron microscopy structure of CLHM1 ion channel from Caenorhabditis elegans. Protein Sci. 2020 Aug;29(8):1803-1815. doi: 10.1002/pro.3904. Epub 2020 Jun 30. PMID:32557855 doi:http://dx.doi.org/10.1002/pro.3904