Abstract：
Leucine-rich repeat kinase 2 (LRRK2) is the most common gene responsible for familial Parkinson\'s disease (PD). The gene product of LRRK2 contains multiple protein domains, including armadillo repeat, ankyrin repeat, leucine-rich repeat (LRR), Ras-of-complex (ROC), C-terminal of ROC (COR), kinase, and WD40 domains. In this study, we performed genetic screening of LRRK2 in our PD cohort, detecting sixteen LRRK2 rare variants. Among them, we selected seven variants that are likely to be familial and characterized them in terms of LRRK2 protein function, along with clinical information and one pathological analysis. The seven variants were S1120P and N1221K in the LRR domain; I1339M, S1403R, and V1447M in the ROC domain; and I1658F and D1873H in the COR domain. The kinase activity of the LRRK2 variants N1221K, S1403R, V1447M, and I1658F toward Rab10, a well-known phosphorylation substrate, was higher than that of wild-type LRRK2. LRRK2 D1873H showed enhanced self-association activity, whereas LRRK2 S1403R and D1873H showed reduced microtubule-binding activity. Pathological analysis of a patient with the LRRK2 V1447M variant was also performed, which revealed Lewy pathology in the brainstem. No functional alterations in terms of kinase activity, self-association activity, and microtubule-binding activity were detected in LRRK2 S1120P and I1339M variants. However, the patient with PD carrying LRRK2 S1120P variant also had a heterozygous Glucosylceramidase beta 1 (GBA1) L444P variant. In conclusion, we characterized seven LRRK2 variants potentially associated with PD. Five of the seven variants in different LRRK2 domains exhibited altered properties in kinase activity, self-association, and microtubule-binding activity, suggesting that each domain variant may contribute to disease progression in different ways.
摘要：
富含亮氨酸重复序列激酶2(LRRK2)是家族性帕金森病(PD)最常见的基因。LRRK2的基因产物含有多个蛋白质结构域,包括Armadillo重复,Ankyrin重复,富含亮氨酸的重复序列（LRR），复合物的Ras(ROC)，ROC（COR）的C端，激酶，和WD40域。在这项研究中,我们在PD队列中进行了LRRK2的遗传筛查，检测十六个LRRK2罕见变异。其中,我们选择了七个可能是家族性的变体，并根据LRRK2蛋白功能对其进行了表征，以及临床信息和病理分析。七个变体是LRR域中的S1120P和N1221K；I1339M，S1403R,和ROC结构域中的V1447M;和COR结构域中的I1658F和D1873H。LRRK2变体N1221K的激酶活性，S1403R,V1447M,和I1658F对Rab10，一种众所周知的磷酸化底物，高于野生型LRRK2。LRRK2D1873H显示增强的自我联想活动，而LRRK2S1403R和D1873H显示降低的微管结合活性。还对患有LRRK2V1447M变体的患者进行了病理分析，显示了脑干的路易病理。在激酶活性方面没有功能改变，自我联想活动，在LRRK2S1120P和I1339M变体中检测到微管结合活性。然而,携带LRRK2S1120P变异体的PD患者也有一个杂合的葡萄糖基神经酰胺酶β1(GBA1)L444P变异体.总之,我们鉴定了7种可能与PD相关的LRRK2变体。不同LRRK2结构域中的七个变体中的五个在激酶活性方面表现出改变的性质,自我联想,和微管结合活性，这表明每个结构域变异可能以不同的方式促进疾病进展。
