ジャーナル: Nat Struct Mol Biol / 年: 2025 タイトル: Conformational plasticity of a BiP-GRP94 chaperone complex. 著者: Joel Cyrille Brenner / Linda Charlotte Zirden / Lana Buzuk / Yasser Almeida-Hernandez / Lea Radzuweit / Joao Diamantino / Farnusch Kaschani / Markus Kaiser / Elsa Sanchez-Garcia / Simon ...著者: Joel Cyrille Brenner / Linda Charlotte Zirden / Lana Buzuk / Yasser Almeida-Hernandez / Lea Radzuweit / Joao Diamantino / Farnusch Kaschani / Markus Kaiser / Elsa Sanchez-Garcia / Simon Poepsel / Doris Hellerschmied / 要旨: Hsp70 and Hsp90 chaperones and their regulatory cochaperones are critical for maintaining protein homeostasis. Glucose-regulated protein 94 (GRP94), the sole Hsp90 chaperone in the secretory pathway ...Hsp70 and Hsp90 chaperones and their regulatory cochaperones are critical for maintaining protein homeostasis. Glucose-regulated protein 94 (GRP94), the sole Hsp90 chaperone in the secretory pathway of mammalian cells, is essential for the maturation of important secretory and transmembrane proteins. Without the requirement of cochaperones, the Hsp70 protein BiP controls regulatory conformational changes of GRP94, the structural basis of which has remained elusive. Here we biochemically and structurally characterize the formation of a BiP-GRP94 chaperone complex and its transition to a conformation expected to support the loading of substrate proteins from BiP onto GRP94. BiP initially binds to the open GRP94 dimer through an interaction interface that is conserved among Hsp70 and Hsp90 paralogs. Subsequently, binding of a second BiP protein stabilizes a semiclosed GRP94 dimer, thereby advancing the chaperone cycle. Our findings highlight a fundamental mechanism of direct Hsp70-Hsp90 cooperation, independent of cochaperones.
全体 : Recombinant complex of human GRP94, BiP, and a Halo-Tag 2 (HT2) s...
全体
名称: Recombinant complex of human GRP94, BiP, and a Halo-Tag 2 (HT2) substrate
要素
複合体: Recombinant complex of human GRP94, BiP, and a Halo-Tag 2 (HT2) substrate
複合体: GRP94
タンパク質・ペプチド: GRP94 delta1-72, N-term Strep-tag
複合体: BiP
タンパク質・ペプチド: BiP, His-tagged
複合体: Halo-Tag 2
タンパク質・ペプチド: HaloTag2, N-term Spot-Tag
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超分子 #1: Recombinant complex of human GRP94, BiP, and a Halo-Tag 2 (HT2) s...
超分子
名称: Recombinant complex of human GRP94, BiP, and a Halo-Tag 2 (HT2) substrate タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: all 詳細: Complex was reconstituted from individual purified proteins and then purified and fixated by glycerol gradient ultracentrifugation with glutaraldehyde cross-linking (GraFix)
タイプ: NEGATIVE / 材質: Uranyl formate 詳細: 4 ul of the GraFix fraction was applied to a Copper 400 Mesh grids with continuous carbon (Electron Microscopy Sciences) after glow discharge, incubated for 30 s, immediately blotted with ...詳細: 4 ul of the GraFix fraction was applied to a Copper 400 Mesh grids with continuous carbon (Electron Microscopy Sciences) after glow discharge, incubated for 30 s, immediately blotted with filter paper and stained via five successive short incubations of 2% (w/v) uranyl formate (Science Services). The excess stain was removed with filter paper and the grids dried before imaging