ジャーナル: Nat Commun / 年: 2023 タイトル: Allosteric regulation of the 20S proteasome by the Catalytic Core Regulators (CCRs) family. 著者: Fanindra Kumar Deshmukh / Gili Ben-Nissan / Maya A Olshina / Maria G Füzesi-Levi / Caley Polkinghorn / Galina Arkind / Yegor Leushkin / Irit Fainer / Sarel J Fleishman / Dan Tawfik / Michal Sharon / 要旨: Controlled degradation of proteins is necessary for ensuring their abundance and sustaining a healthy and accurately functioning proteome. One of the degradation routes involves the uncapped 20S ...Controlled degradation of proteins is necessary for ensuring their abundance and sustaining a healthy and accurately functioning proteome. One of the degradation routes involves the uncapped 20S proteasome, which cleaves proteins with a partially unfolded region, including those that are damaged or contain intrinsically disordered regions. This degradation route is tightly controlled by a recently discovered family of proteins named Catalytic Core Regulators (CCRs). Here, we show that CCRs function through an allosteric mechanism, coupling the physical binding of the PSMB4 β-subunit with attenuation of the complex's three proteolytic activities. In addition, by dissecting the structural properties that are required for CCR-like function, we could recapitulate this activity using a designed protein that is half the size of natural CCRs. These data uncover an allosteric path that does not involve the proteasome's enzymatic subunits but rather propagates through the non-catalytic subunit PSMB4. This way of 20S proteasome-specific attenuation opens avenues for decoupling the 20S and 26S proteasome degradation pathways as well as for developing selective 20S proteasome inhibitors.