Published In

Biorxiv : the Preprint Server for Biology

Document Type

Pre-Print

Publication Date

3-27-2024

Subjects

Proteins -- Metabolism, Proteomics, Molecular biology

Abstract

αB-crystallin is an archetypical member of the small heat-shock proteins (sHSPs) vital for cellular proteostasis and mitigating protein misfolding diseases. Gaining insights into the principles defining their molecular organization and chaperone function have been hindered by intrinsic dynamic properties and limited high-resolution structural analysis. To disentangle the mechanistic underpinnings of these dynamical properties, we mutated a conserved IXI-motif located within the N-terminal (NT) domain of human αB-crystallin. This resulted in a profound structural transformation, from highly polydispersed caged-like native assemblies into a comparatively well-ordered helical fibril state amenable to high-resolution cryo-EM analysis. The reversible nature of the induced fibrils facilitated interrogation of functional effects due to perturbation of the NT-IXI motif in both the native-like oligomer and fibril states. Together, our investigations unveiled several features thought to be key mechanistic attributes to sHSPs and point to a critical significance of the NT-IXI motif in αB-crystallin assembly, dynamics and chaperone activity.

Rights

© Copyright the author(s) 2024

The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY 4.0 International license.

Description

This is the author’s version of a work that was accepted for publication. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as: Reichow, S. L., & McFarland, R. (2024). Dynamic fibrillar assembly of αB-crystallin induced by perturbation of the conserved NT-IXI motif resolved by cryo-EM. bioRxiv, 2024-03.

DOI

10.1101/2024.03.22.586355

Persistent Identifier

https://archives.pdx.edu/ds/psu/41781

Included in

Chemistry Commons

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