5 January 2011
Imam SZ, Zhou Q, Yamamoto A, Valente AJ, Ali SF, Bains M, Roberts JL, Kahle PJ, Clark RA, Li S
Mutations in parkin, an E3 ubiquiti n ligase, are the most common cause of autosomal-recessive Parkinson's disease (PD). Here, we show that the stress-signaling non-receptor tyrosine kinasec-Abl links parkin to sporadic forms of PD via tyrosine phosphorylation.
Under oxidative and dopaminergic stress, c-Abl was activated in cultured neuronal cells and in striatum of adult C57BL/6mice. Activated c-Abl was found in the striatum of PD patients. Concomitantly, parkin was tyrosine-phosphorylated, causing loss of its ubiquitin ligase and cytoprotective activities, and the accumulation of parkin substrates, AIMP2 (aminoacyl tRNA synthetase complex-interacting multifunctional protein 2) (p38/JTV-1) and FBP-1.STI-571, a selective c-Abl inhibitor, prevented tyrosine phosphorylation of parkin and restored its E3 ligase activity and cytoprotective function both in vitro and in vivo.
Our results suggest that tyrosine phosphorylation of parkin by c-Abl is a major post-translational modification that leads to loss of parkin function and disease progression in sporadic PD. Moreover, inhibition of c-Abl offers new therapeutic opportunities for blocking PD progression.