9JSX

G175S PMEL CAF amyloid - in vitro polymerized

9JSX の概要

• エントリーDOI: 10.2210/pdb9jsx/pdb
• 関連するPDBエントリー: 9JST 9JSU 9JSV 9JSW
• EMDBエントリー: 61782 61783 61784 61785 61786
• 分子名称: M-alpha (1 entity in total)
• 機能のキーワード: melanosome, melanoma, pigment, melanin, amyloid, glaucoma, structural protein
• 由来する生物種: Homo sapiens (human)
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 30290.74

構造登録者

Oda, T.,Yanagisawa, H. (登録日: 2024-10-01, 公開日: 2024-10-09, 最終更新日: 2025-07-16)

主引用文献

Yanagisawa, H.,Arai, H.,Wang, T.,Miyazawa, H.,Kikkawa, M.,Oda, T.
Cryo-EM of wild-type and mutant PMEL amyloid cores reveals structural mechanism of pigment dispersion syndrome.
Nat Commun, 16:5411-5411, 2025

PubMed Abstract: PMEL amyloids serve as essential scaffolds for melanin deposition in melanosomes, playing a crucial role in pigmentation. Despite their importance, the high-resolution structure of PMEL amyloids has remained unresolved. Using cryo-electron microscopy, we determine near-atomic resolution structures of wild-type PMEL amyloid core, revealing two distinct polymorphic forms with structural features. We further investigate the pathogenic G175S mutation associated with pigment dispersion syndrome (PDS). Structural analysis reveales that G175S introduces an additional hydrogen bond, stabilizing an alternative fibril conformation. In vitro, the G175S mutant exhibits a fourfold increase in polymerization efficiency compared to the wild type. In cells, G175S expression resultes in a twofold increase in intracellular amyloid content and a ~70% increase in extracellular amyloids, without altering melanosome morphology or number. These results indicate that the G175S mutation enhances amyloidogenesis within melanosomes, elevating amyloid load and potentially contributing to PDS pathophysiology. This study provides molecular insights into PMEL amyloid formation, highlighting its structural diversity and dysregulation in pigmentation disorders.

PubMed: 40595665
DOI: 10.1038/s41467-025-61233-y

実験手法

ELECTRON MICROSCOPY (1.79 Å)