Evidence map›Paper›PMID 39747283›Full record

ArticleScientific reports2025

Conformational landscape of soluble α-klotho revealed by cryogenic electron microscopy.

Nicholas J Schnicker, Zhen Xu, Mohammad Amir, Lokesh Gakhar, Chou-Long Huang

Abstract read
In one paragraph

Article in Scientific reports, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

  1. Review
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  3. Article
4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

5 authors.

Nicholas J Schnicker *Protein and Crystallography Facility, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA. nicholas-schnicker@uiowa.edu.
Zhen Xu *Protein and Crystallography Facility, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
Mohammad Amir *Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
Lokesh GakharProtein and Crystallography Facility, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
Chou-Long HuangDepartment of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA. chou-long-huang@uiowa.edu.

Funding

Pacific Northwest Center for Cryo-EM - Screening supplementU24GM129547 · NIGMS · OREGON HEALTH & SCIENCE UNIVERSITY · PI EVANS, JAMES E, GOUAUX, JAMES E · 2018 to 2023
$54.8M
University of Iowa Hawkeye Intellectual and Developmental Disabilities Research Center (Hawk-IDDRC)P50HD103556 · NICHD · UNIVERSITY OF IOWA · PI EDWIN TED G. ABEL, Lane Strathearn · 2021 to 2026
$8.5M
Klotho and Chronic Kidney DiseaseR01DK100605 · NIDDK · UT SOUTHWESTERN MEDICAL CENTER · PI HUANG, CHOU-LONG · 2014 to 2023
$3.5M
Regulation of Renal Calcium Transport in Health and DiseaseR01DK109887 · NIDDK · UT SOUTHWESTERN MEDICAL CENTER · PI HUANG, CHOU-LONG · 2016 to 2020
$1.8M
NICHD NIH HHS P50 HD103556NIDDK NIH HHS DK100605NIDDK NIH HHS R01 DK100605NIDDK NIH HHS R01 DK109887NIGMS NIH HHS U24 GM129547
6 · The paper itself

Abstract

α-Klotho (KLA) is a type-1 membranous protein that can associate with fibroblast growth factor receptor (FGFR) to form co-receptor for FGF23. The ectodomain of unassociated KLA is shed as soluble KLA (sKLA) to exert FGFR/FGF23-independent pleiotropic functions. The previously determined X-ray crystal structure of the extracellular region of sKLA in complex with FGF23 and FGFR1c suggests that sKLA functions solely as an on-demand coreceptor for FGF23. To understand the FGFR/FGF23-independent pleiotropic functions of sKLA, we investigated biophysical properties and structure of apo-sKLA. Single particle cryogenic electron microscopy (cryo-EM) revealed a 3.3 Å resolution structure of apo-sKLA that overlays well with its counterpart in the ternary complex with several distinct features. Compared to the ternary complex, the KL2 domain of apo-sKLA is more flexible. Three-dimensional variability analysis revealed that apo-sKLA adopts conformations with different KL1-KL2 interdomain bending and rotational angles. Mass photometry revealed that sKLA can form a stable structure with FGFR and/or FGF23 as well as sKLA dimer in solution. Cryo-EM supported the dimeric structure of sKLA. Recent studies revealed that FGF23 contains two KLA-binding sites. Our computational studies revealed that each site binds separate KLA in the dimer. The potential multiple forms and shapes of sKLA support its role as FGFR-independent hormone with pleiotropic functions. The ability of FGF23 to engage two KLA's simultaneously raises a potential new mechanism of action for FGF23-mediated signaling by the membranous klotho.

Indexed as

Cryoelectron MicroscopyFibroblast Growth Factor-23Klotho ProteinsFibroblast Growth FactorsGlucuronidaseHumansModels, MolecularProtein BindingProtein ConformationProtein DomainsFGF23 protein, humanFibroblast Growth Factor-23Fibroblast Growth FactorsGlucuronidaseKlotho Proteins3D variability analysis (3DVA)Cryogenic electron microscopy (cryo-EM)DimerFibroblast growth factor (FGF)MonomerSoluble alpha-klotho (sKLA)Ternary complex

Identifiers

PMID39747283
PMCPMC11696049

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.