LRRK2 and Parkinson disease: Furthermore, RAB29 is also a substrate of LRRK2 in human HEK293 cells; LRRK2 with kinase overactive PD mutations LRRK2R1441C, LRRK2Y1699C and LRRK2G2019S present a 4-fold increase of LRRK2 mediated phosphorylation of RAB29 [178], suggesting interdependent regulation between these two proteins.