Title: Distinctive roles of Rac1 and Rab29 in LRRK2 mediatedmem-brane trafficking and neurite outgrowth


Authors: Min Feng1, Xin Hu1, Na Li1, Fan Hu2, Fei Chang1, Hongfei Xu1, Yongjian Liu1


Institutions: 1Department of Physiology; 2Analyticaland Testing Center, School of Basic Medical Science, Nanjing Medical University, Nanjing, Jiangsu 211166, China


Abstract: Parkinsons disease (PD) associated leucine-rich repeat kinase 2 (LRRK2) mutants have shown pathogenic effects on variety of subcellular processes.Two small GTPases Rac1 and Rab29 have been indicated as possible downstream effectors participating in LRRK2 signaling but their detail mechanisms remain unclear. In this study, we have used biochemical and cell biology approaches to address whether two GTPases interact with LRRK2 and hence function differently in LRRK2 mediated pathogenesis.Here we show thatRac1 and Rab29 specifically interact with LRRK2with higher affinity for Rab29and with different preference in functional domain binding. Mutant Rab29 but not Rac1 alters theendosome-to-TGN retrograde trafficking of a cargo protein cation-independent mannose-6-phosphate receptor (CI-M6PR) and its stability. On the other hand, overexpressedwild type Rab29 but not Rac1 rescue the altered retrograde membrane trafficking induced by the pathogenic mutant LRRK2G2019S. Furthermore, both Rac1 and Rab29 can rescue the neurite shortening in differentiated SH-SY5Y cells induced by LRRK2G2019S. Our study strongly suggests that Rac1 and Rab29 are involved in the distinct functions as downstream effectors in LRRK2 signaling pathways.


Keywords: Parkinsons disease, LRRK2, Rac1, Rab29, retrograde trafficking


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J Biomed Res published on 05 June, 2017, doi:10.7555/JBR.31.20170039