HECT类泛素连接酶Smurf1自身调控机制的研究

Intermolecular interaction of HECT-type ligase Smurf1

目的泛素连接酶Smurf1在胚胎发育、骨形成调控和细胞极性控制中具有重要的生理功能,但是其自身的泛素化降解机制尚不清楚。本论文拟研究Smurf1分子间自我调控的机制,以期揭示一种新的泛素连接酶调控方式。方法通过免疫共沉淀实验确证了Smurf1分子间存在相互作用,体内泛素化、半衰期及降解实验研究了Smurf1的自身泛素化降解。结果 Smurf1存在分子间相互作用和泛素化降解,这种分子间的相互调控是由C2和WW结构域介导。结论 Smurf1分子间存在自我泛素化修饰及蛋白酶体依赖的降解,是一种新的HECT类泛素连接酶的调控机制。

Objective The homologous to E6AP C-terminus（HECT） domain-type ubiquitin ligase Smurf1 plays a critical role in regulation of embryogenesis,bone formation and cell polarity.However,the regulatory mechanism of Smurf1 cis-E3 ligase activity is still not fully understood.This study aims to investigate the intermolecular interaction of Smurf1 and to further reveal a new regulatory mechanism of ubiquitin ligase.Methods Overexpression and in vivo ubiquitination assay were used to study the intermolecular interaction of Smurf1.Co-immunoprecipitation assay was used to determine which domain mediates the interaction of Smurf1.Results Smurf1 was subject to intermolecular interaction and intermolecular degradation,both of which were mediated between the C2 and the WW domains.Conclusion The intermolecular regulatory mode of Smurf1 might represent a novel model of E3 activity control.