タンパク質のプロセシングに関する新たな理解、アルツハイマーやがん研究への影響も(New understanding of protein processing could have implications for Alzheimer’s and some cancers)

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2025-06-05 ロックフェラー大学


Three dimensional cryo-EM structure of VCP (blue and purple) bound to three VCPIP1 promoters (red, orange, and yellow). (Courtesy of Kapoor lab)

ロックフェラー大学の研究チームは、酵素VCPと脱ユビキチン化酵素VCPIP1が協調して細胞内のタンパク質分解を制御する仕組みを解明。VCPがタンパク質を展開し、VCPIP1がユビキチンタグを除去するプロセスを、単一分子質量測定とクライオ電子顕微鏡で可視化しました。VCPはATPを使わずにVCPIP1の活性を促進でき、効率的な分解が示唆されます。この発見はアルツハイマー病やがん治療の新たな手がかりとなる可能性があります。

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必須アンフォールダーゼであるVCPと脱ユビキチン化酵素の結合に関する構造的洞察
Structural insights into the coupling between VCP, an essential unfoldase, and a deubiquitinase

Lauren E. Vostal,Noa E. Dahan,Matthew J. Reynolds,Lily I. Kronenberg,Tarun M. Kapoor
Journal of Cell Biology  Published:March 14 2025
DOI:https://doi.org/10.1083/jcb.202410148

Proteostasis involves degradation and recycling of proteins from organelles, membranes, and multiprotein complexes. These processes can depend on protein extraction and unfolding by the essential mechanoenzyme valosin-containing protein (VCP) and on ubiquitin chain remodeling by ubiquitin-specific proteases known as deubiquitinases (DUBs). How the activities of VCP and DUBs are coordinated is poorly understood. Here, we focus on the DUB VCPIP1, a VCP interactor required for post-mitotic Golgi and ER organization. We determine ∼3.3 Å cryogenic electron microscopy structures of VCP-VCPIP1 complexes in the absence of added nucleotide or the presence of an ATP analog. We find that up to 3 VCPIP1 protomers interact with the VCP hexamer to position VCPIP1’s catalytic domain at the exit of VCP’s central pore, poised to cleave ubiquitin following substrate unfolding. We observe competition between VCPIP1 and other cofactors for VCP binding and show that VCP stimulates VCPIP1’s DUB activity. Together, our data suggest how the two enzyme activities can be coordinated to regulate proteostasis.

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