Abteilung für Systembiochemie, Institut für Physiologische Chemie, Medizinische Fakultät, Ruhr-Universität Bochum, Germany.
FEBS J. 2012 Jun;279(11):2060-70. doi: 10.1111/j.1742-4658.2012.08591.x. Epub 2012 May 2.
The RING finger peroxins Pex2p, Pex10p and Pex12p are central components of the peroxisomal matrix protein import machinery. The RING domain enables each of these proteins to exhibit ubiquitin-protein ligase activity, which has been linked to ubiquitin-dependent regulation of the peroxisomal import receptor Pex5p. The RING peroxins are considered to form a heteromeric complex in vivo, although the elucidation of the structural assembly, as well as the functional interplay of the RING domains, has remained elusive. Using in vitro approaches, we show that the RING domains form a heteromeric complex with Pex10p(RING) as a central component that directly binds the Pex2p(RING) and Pex12p(RING). The RING domains proved to function as heteromeric pairs that display an Pex10p-dependent enhanced ligase activity in an ubiquitin conjugating enzyme-selective manner.
RING 指蛋白 Pex2p、Pex10p 和 Pex12p 是过氧化物酶体基质蛋白输入机制的核心组成部分。RING 结构域使这些蛋白中的每一个都能够表现出泛素-蛋白连接酶的活性，这种活性与过氧化物酶体输入受体 Pex5p 的泛素依赖性调节有关。RING 过氧化物酶体被认为在体内形成异源三聚体复合物，尽管其结构组装以及 RING 结构域的功能相互作用仍然难以阐明。我们使用体外方法表明，RING 结构域与 Pex10p(RING)形成异源三聚体复合物作为中央组件，该中央组件直接结合 Pex2p(RING)和 Pex12p(RING)。RING 结构域被证明可以作为异源二聚体发挥作用，以泛素连接酶选择性的方式表现出依赖于 Pex10p 的增强的连接酶活性。
