The Parkinson's disease-associated mutation N1437H impairs conformational dynamics in the G domain of LRRK2
The Parkinson's disease-associated mutation N1437H impairs conformational dynamics in the G domain of LRRK2
复制标题
帕金森病相关突变 N1437H 损害 LRRK2 G 结构域的构象动力学。
DOI：
10.1096/fj.201802031r
复制
发表时间：
2019-04-01
期刊：
影响因子：
4.8
通讯作者：
Liao, Jingling
中科院分区：
文献类型：
--
作者：
Huang, Xiaorong;Wu, Chunxiang;Liao, Jingling
富含亮氨酸重复蛋白2(LRRK2)的复合蛋白(ROC)的GTPase结构域RAS突变与帕金森病相关，导致其激活域异常过度激活。然而，其中涉及的机制仍不清楚。最近的研究表明，当LRRK2与GTP或鸟苷二磷酸结合时，LRRK2的G结构域在单体和二聚体之间循环，而帕金森病(PD)相关的R1441C/G/H突变会削弱G结构域单体-二聚体的动力学，并将G结构域捕获在构成单体构象中。这让我们质疑G结构域的其他疾病相关突变是否也会影响其构象。在这里，我们报告了另一个与PD相关的N1437H突变也损害了它的单体-二聚体构象动力学和GTPase活性。与R1441突变相比，ROCN1437H在溶液中以稳定的二聚体构象锁定，其GTP酶活性比野生型低4倍。此外，与其他致病G区突变相比，N1437H突变使GTP结合亲和力降低了2.5倍。此外，发现ROCN1437H具有较慢的GTP解离速率，表明N1437H可能中断了核苷酸交换循环。综上所述，我们的数据支持构象动力学对LRRK2 GTPase活性是重要的，并且N1437H突变通过将ROC结构域锁定在持续的二聚体状态而削弱GTPase活性。
Parkinson disease-associated mutations within the GTPase domain Ras of complex proteins (ROC) of leucine rich repeat kinase 2 (LRRK2) result in an abnormal over-activation of its kinase domain. However, the mechanisms involved remain unclear. Recent study has shown that LRRK2 G-domain cycles between monomeric and dimeric conformations upon binding to GTP or guanosine diphosphate, and that the Parkinson's disease (PD)-associated R1441C/G/H mutations impair the G-domain monomer-dimer dynamics and trap the G-domain in a constitutive monomeric conformation. That led us to question whether other disease-associated mutations in G-domain would also affect its conformation. Here, we report that another PD-associated N1437H mutation also impairs its monomer-dimer conformational dynamics and GTPase activity. In contrast with mutations at R1441, ROCN1437H was found to be locked in a stable dimeric conformation in solution and its GTPase activity was similar to 4-fold lower than that of the wild-type. Furthermore, the N1437H mutation reduced the GTP binding affinity by similar to 2.5-fold when compared with other pathogenic G-domain mutations. Moreover, ROCN1437H was found to have a slower GTP dissociation rate, indicating that N1437H might interrupt the nucleotide exchange cycle. Taken together, our data support that conformational dynamics is important for LRRK2 GTPase activity and that the N1437H mutation impairs GTPase activity by locking the ROC domain in a persistently dimeric state.