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-Structure paper
タイトル | Structural basis for Ca activation of the heteromeric PKD1L3/PKD2L1 channel. |
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ジャーナル・号・ページ | Nat Commun, Vol. 12, Issue 1, Page 4871, Year 2021 |
掲載日 | 2021年8月11日 |
著者 | Qiang Su / Mengying Chen / Yan Wang / Bin Li / Dan Jing / Xiechao Zhan / Yong Yu / Yigong Shi / |
PubMed 要旨 | The heteromeric complex between PKD1L3, a member of the polycystic kidney disease (PKD) protein family, and PKD2L1, also known as TRPP2 or TRPP3, has been a prototype for mechanistic characterization ...The heteromeric complex between PKD1L3, a member of the polycystic kidney disease (PKD) protein family, and PKD2L1, also known as TRPP2 or TRPP3, has been a prototype for mechanistic characterization of heterotetrametric TRP-like channels. Here we show that a truncated PKD1L3/PKD2L1 complex with the C-terminal TRP-fold fragment of PKD1L3 retains both Ca and acid-induced channel activities. Cryo-EM structures of this core heterocomplex with or without supplemented Ca were determined at resolutions of 3.1 Å and 3.4 Å, respectively. The heterotetramer, with a pseudo-symmetric TRP architecture of 1:3 stoichiometry, has an asymmetric selectivity filter (SF) guarded by Lys2069 from PKD1L3 and Asp523 from the three PKD2L1 subunits. Ca-entrance to the SF vestibule is accompanied by a swing motion of Lys2069 on PKD1L3. The S6 of PKD1L3 is pushed inward by the S4-S5 linker of the nearby PKD2L1 (PKD2L1-III), resulting in an elongated intracellular gate which seals the pore domain. Comparison of the apo and Ca-loaded complexes unveils an unprecedented Ca binding site in the extracellular cleft of the voltage-sensing domain (VSD) of PKD2L1-III, but not the other three VSDs. Structure-guided mutagenic studies support this unconventional site to be responsible for Ca-induced channel activation through an allosteric mechanism. |
リンク | Nat Commun / PubMed:34381056 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.1 - 3.4 Å |
構造データ | EMDB-30606, PDB-7d7e: EMDB-30607, PDB-7d7f: |
化合物 | ChemComp-NAG: ChemComp-CA: |
由来 |
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キーワード | TRANSPORT PROTEIN / Heterotetrameric TRP channel / Calcium / Primary cilia / PKD |