The special role of Rpn6 of Serine 14 has been confirmed by mutagenesis, specifically by the capacity of the phosphomimetic mutant (S14D) to enhance and the “phospho-dead” S14A mutation to decrease both proteasome activity and the clearance of …

2023年8月29日 · By creating knock-in mice and cells to block or mimic pS14-Rpn6, we established in vivo that pS14-RPN6 mediates the activation of 26S proteasomes by cAMP/PKA and that pS14-RPN6 can be augmented to reduce proteotoxicity, potentially identifying a new strategy to treat diseases affected by increased proteotoxic stress.

Here, we report the crystal structure of one of the RP subunits, Rpn6, and we describe its integration into the cryo-EM density map of the 26S holocomplex at 9.1 Å resolution. Rpn6 consists of an α-solenoid-like fold and a proteasome COP9/signalosome eIF3 (PCI) module in a right-handed suprahelical configuration.

Pharmacological agents that raise cAMP and activate protein kinase A (PKA) stimulate 26S proteasome activity, phosphorylation of subunit Rpn6, and intracellular degradation of misfolded proteins. We investigated whether a similar proteasome activation occurs in response to hormones and under various physiological conditions that raise cAMP.

2017年3月3日 · This leads to phosphorylation of Rpn6 (but not Rpt6) at Ser14, shown by Phos-tag SDS/PAGE and confirmed by MS. Rpn6-S14 phosphorylation enhances proteasome ATPase activity and promotes the formation of doubly capped (30S) proteasome, hence accelerating the degradation of short-lived proteins (Table 1).

2023年9月15日 · This study establishes in animals that pS14-Rpn6 mediates the activation of 26S proteasomes by PKA and that the reduced pS14-Rpn6 is a key pathogenic factor in cardiac proteinopathy, thereby identifying a new therapeutic target to reduce cardiac proteotoxicity.

2011年12月20日 · Here, we report the crystal structure of one of the RP subunits, Rpn6, and we describe its integration into the cryo-EM density map of the 26S holocomplex at 9.1 Å resolution. Rpn6 consists of an α-solenoid-like fold and a proteasome COP9/signalosome eIF3 (PCI) module in a right-handed suprahelical configuration.

Rpn6 由一个类似 alpha 螺线管的折叠和一个蛋白酶体 COP9/信号小体 eIF3 (PCI) 模块组成，采用右手超螺旋结构。 Rpn6 的高度保守的表面积分别与来自 alpha 和 ATPase 环的 Pre8 (alpha2) 和 Rpt6 亚基的保守表面相互作用。

亲和层析和质谱分析技术表明 Rpn6 是调节 Nrf2 信号通路的潜在靶蛋白。 体外亲和实验进一步证实， DDO-7263 通过与 Rpn6 结合来上调 Nrf2，从而阻断 26S 蛋白酶体的组装和随后泛素化 Nrf2 的降解。

2022年4月3日 · 综合所有研究结果表明：DDO-7263 通过与Rpn6蛋白结合阻断26S 蛋白酶体的组装和泛素化Nrf2的降解，从而激活Nrf2-ARE抗氧化通路。 Rpn6的靶标鉴定为研究Nrf2抗氧化途径和蛋白质积累或降解的调控提供了新的分子机制。 图2. 基于小分子探针及蛋白质组的靶标垂钓过程。 (A) 探针5、DDO-7263 和 D-生物素的结构。 (B) 靶标垂钓实验示意图。 (C) 靶标垂钓实验的SDS-PAGE分离和韦恩图分析结果。 泳道1和泳道2分别代表链霉亲和素树脂和 D-生物素的非 …