| 1. |
- Chi, Gamma, et al.
(författare)
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Cryo-EM structure of the human Kv3.1 channel reveals gating control by the cytoplasmic T1 domain
- 2022
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Kv3 channels have distinctive gating kinetics tailored for rapid repolarization in fast-spiking neurons. Malfunction of this process due to genetic variants in the KCNC1 gene causes severe epileptic disorders, yet the structural determinants for the unusual gating properties remain elusive. Here, we present cryo-electron microscopy structures of the human Kv3.1a channel, revealing a unique arrangement of the cytoplasmic tetramerization domain T1 which facilitates interactions with C-terminal axonal targeting motif and key components of the gating machinery. Additional interactions between S1/S2 linker and turret domain strengthen the interface between voltage sensor and pore domain. Supported by molecular dynamics simulations, electrophysiological and mutational analyses, we identify several residues in the S4/S5 linker which influence the gating kinetics and an electrostatic interaction between acidic residues in alpha 6 of T1 and R449 in the pore-flanking S6T helices. These findings provide insights into gating control and disease mechanisms and may guide strategies for the design of pharmaceutical drugs targeting Kv3 channels. Here, Chi et al. report cryo-EM structures of the human Kv3.1a channel, revealing a unique arrangement of the cytoplasmic T1 domain, which allows the interactions with the C-terminal axonal targeting motif and key components of the gating machinery. These findings provide insights into the functional relevance of previously unknown interdomain interactions in Kv3 channels and may guide the design of new pharmaceutical drugs.
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| 2. |
- Szykowska, Aleksandra, et al.
(författare)
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Selection and structural characterization of anti-TREM2 scFvs that reduce levels of shed ectodomain
- 2021
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Ingår i: Structure. - : Elsevier BV. - 0969-2126 .- 1878-4186. ; 29:11, s. 1241-
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Tidskriftsartikel (refereegranskat)abstract
- Mutations in TREM2, a receptor expressed by microglia in the brain, are associated with an increased risk of neurodegeneration, including Alzheimer's disease. Numerous studies support a role for TREM2 in sensing damaging stimuli and triggering signaling cascades necessary for neuroprotection. Despite its significant role, ligands and regulators of TREM2 activation, and the mechanisms governing TREM2-dependent responses and its cleavage from the membrane, remain poorly characterized. Here, we present phage display generated antibody single-chain variable fragments (scFvs) to human TREM2 immunoglobulin-like domain. Co-crystal structures revealed the binding of two scFvs to an epitope on the TREM2 domain distal to the putative ligand-binding site. Enhanced functional activity was observed for oligomeric scFv species, which inhibited the production of soluble TREM2 in a HEK293 cell model. We hope that detailed characterization of their epitopes and properties will facilitate the use of these renewable binders as structural and functional biology tools for TREM2 research.
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