LRRK2 Facilitates tau Phosphorylation through Strong Interaction with tau and cdk5

Biochemistry. 2015 Aug 25;54(33):5198-208. doi: 10.1021/acs.biochem.5b00326. Epub 2015 Aug 13.


Leucine-rich repeat kinase 2 (LRRK2) and tau have been identified as risk factors of Parkinson's disease (PD). As LRRK2 is a kinase and tau is hyperphosphorylated in some LRRK2 mutation carriers of PD patients, the obvious hypothesis is that tau could be a substrate of LRRK2. Previous reports that LRRK2 phosphorylates free tau or tubulin-associated tau provide direct support for this proposition. By comparing LRRK2 with cdk5, we show that wild-type LRRK2 and the G2019S mutant phosphorylate free recombinant full-length tau protein with specific activity 480- and 250-fold lower than cdk5, respectively. More strikingly tau binds to wt LRRK2 or the G2019S mutant 140- or 200-fold more strongly than cdk5. The extremely low activity of LRRK2 but strong binding affinity with tau suggests that LRRK2 may facilitate tau phosphorylation as a scaffold protein rather than as a major tau kinase. This hypothesis is further supported by the observation that (i) cdk5 or tau coimmunoprecipitates with endogenous LRRK2 in SH-SY5Y cells, in mouse brain tissue, and in human PBMCs; (ii) knocking down endogenous LRRK2 by its siRNA in SH-SY5Y cells reduces tau phosphorylation at Ser396 and Ser404; (iii) inhibiting LRRK2 kinase activity by its inhibitors has no effect on tau phosphorylation at these two sites; and (iv) overexpressing wt LRRK2, the G2019S mutant, or the D1994A kinase-dead mutant in SH-SY5Y cells has no effect on tau phosphorylation. Our results suggest that LRRK2 facilitates tau phosphorylation indirectly by recruiting tau or cdk5 rather than by directly phosphorylating tau.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Biocatalysis
  • Brain / metabolism
  • Cell Line, Tumor
  • Cyclin-Dependent Kinase 5 / metabolism*
  • Humans
  • Kinetics
  • Leucine-Rich Repeat Serine-Threonine Protein Kinase-2
  • Leukocytes, Mononuclear / metabolism
  • Mice
  • Molecular Sequence Data
  • Mutation
  • Parkinson Disease / genetics
  • Phosphorylation
  • Protein Binding
  • Protein Serine-Threonine Kinases / chemistry
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*
  • Tubulin / metabolism
  • tau Proteins / metabolism*


  • Tubulin
  • tau Proteins
  • Cyclin-Dependent Kinase 5
  • LRRK2 protein, human
  • Leucine-Rich Repeat Serine-Threonine Protein Kinase-2
  • Lrrk2 protein, mouse
  • Protein Serine-Threonine Kinases