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-Structure paper
タイトル | Cryo-EM structures of an LRRC8 chimera with native functional properties reveal heptameric assembly. |
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ジャーナル・号・ページ | Elife, Vol. 12, Year 2023 |
掲載日 | 2023年3月10日 |
著者 | Hirohide Takahashi / Toshiki Yamada / Jerod S Denton / Kevin Strange / Erkan Karakas / |
PubMed 要旨 | Volume-regulated anion channels (VRACs) mediate volume regulatory Cl and organic solute efflux from vertebrate cells. VRACs are heteromeric assemblies of LRRC8A-E proteins with unknown ...Volume-regulated anion channels (VRACs) mediate volume regulatory Cl and organic solute efflux from vertebrate cells. VRACs are heteromeric assemblies of LRRC8A-E proteins with unknown stoichiometries. Homomeric LRRC8A and LRRC8D channels have a small pore, hexameric structure. However, these channels are either non-functional or exhibit abnormal regulation and pharmacology, limiting their utility for structure-function analyses. We circumvented these limitations by developing novel homomeric LRRC8 chimeric channels with functional properties consistent with those of native VRAC/LRRC8 channels. We demonstrate here that the LRRC8C-LRRC8A(IL1) chimera comprising LRRC8C and 25 amino acids unique to the first intracellular loop (IL1) of LRRC8A has a heptameric structure like that of homologous pannexin channels. Unlike homomeric LRRC8A and LRRC8D channels, heptameric LRRC8C-LRRC8A(IL1) channels have a large-diameter pore similar to that estimated for native VRACs, exhibit normal DCPIB pharmacology, and have higher permeability to large organic anions. Lipid-like densities are located between LRRC8C-LRRC8A(IL1) subunits and occlude the channel pore. Our findings provide new insights into VRAC/LRRC8 channel structure and suggest that lipids may play important roles in channel gating and regulation. |
リンク | Elife / PubMed:36897307 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.4 - 4.0 Å |
構造データ | EMDB-27770, PDB-8dxn: EMDB-27771, PDB-8dxo: EMDB-27772, PDB-8dxp: EMDB-27773, PDB-8dxq: EMDB-27774, PDB-8dxr: |
由来 |
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キーワード | TRANSPORT PROTEIN / LRRC8C / LRRC8A / SWELL / VRAC / Chimera |