University of Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience and Cognition, F-59000 Lille, France.
Department of Cell Biochemistry, University of Groningen, 9747 AG Groningen, The Netherlands.
Cells. 2022 Mar 17;11(6):1018. doi: 10.3390/cells11061018.
The () gene is a major genetic determinant of Parkinson's disease (PD), encoding a homonymous multi-domain protein with two catalytic activities, GTPase and Kinase, involved in intracellular signaling and trafficking. LRRK2 is phosphorylated at multiple sites, including a cluster of autophosphorylation sites in the GTPase domain and a cluster of heterologous phosphorylation sites at residues 860 to 976. Phosphorylation at these latter sites is found to be modified in brains of PD patients, as well as for some disease mutant forms of LRRK2. The main aim of this study is to investigate the functional consequences of LRRK2 phosphorylation or dephosphorylation at LRRK2's heterologous phosphorylation sites. To this end, we generated LRRK2 phosphorylation site mutants and studied how these affected LRRK2 catalytic activity, neurite outgrowth and lysosomal physiology in cellular models. We show that phosphorylation of RAB8a and RAB10 substrates are reduced with phosphomimicking forms of LRRK2, while RAB29 induced activation of LRRK2 kinase activity is enhanced for phosphodead forms of LRRK2. Considering the hypothesis that PD pathology is associated to increased LRRK2 kinase activity, our results suggest that for its heterologous phosphorylation sites LRRK2 phosphorylation correlates to healthy phenotypes and LRRK2 dephosphorylation correlates to phenotypes associated to the PD pathological processes.
LRRK2 基因是帕金森病（PD）的主要遗传决定因素，编码一种具有两种催化活性（GTPase 和激酶）的同源多结构域蛋白，参与细胞内信号转导和运输。LRRK2 在多个位点发生磷酸化，包括 GTPase 结构域中的一组自身磷酸化位点和 860 到 976 残基处的一组异源磷酸化位点。研究发现，这些后一组位点的磷酸化在 PD 患者的大脑中以及某些 LRRK2 疾病突变形式中发生了改变。本研究的主要目的是研究 LRRK2 在其异源磷酸化位点上的磷酸化或去磷酸化对 LRRK2 的功能后果。为此，我们生成了 LRRK2 磷酸化位点突变体，并研究了这些突变如何影响细胞模型中的 LRRK2 催化活性、神经突生长和溶酶体生理学。我们表明，RAB8a 和 RAB10 底物的磷酸化减少了 LRRK2 的磷酸模拟形式，而 RAB29 诱导的 LRRK2 激酶活性的激活增强了 LRRK2 的磷酸化失活形式。考虑到 PD 病理学与 LRRK2 激酶活性增加相关的假设，我们的结果表明，对于其异源磷酸化位点，LRRK2 磷酸化与健康表型相关，而 LRRK2 去磷酸化与与 PD 病理过程相关的表型相关。
