Functional protein kinase arrays reveal inhibition of p-21-activated kinase 4 by alpha-synuclein oligomers.
There is increasing evidence that aggregation of alpha-synuclein contributes to the functional and structural deterioration in the CNS of Parkinson's disease patients and transgenic animal models. alpha-Synuclein binds to various cellular proteins and aggregated alpha-synuclein species may affect their physiological function. In the present study, we used protein arrays spotted with 178 active human kinases for a large-scale analysis of the effects of recombinant alpha-synuclein on kinase activities. Incubation with globular alpha-synuclein oligomers significantly inhibited autophosphorylation of p21-activated kinase (PAK4) compared to treatment with monomeric alpha-synuclein or beta-synuclein. A concentration-dependent inhibition was also observed in a solution-based kinase assay. To show in vivo relevance, we analyzed brainstem protein extracts from alpha-synuclein (A30P) transgenic mice where accumulation of alpha-synuclein oligomers has been demonstrated. By immunoblotting using a phospho-specific antibody, we detected a significant decline in phosphorylation of LIM kinase 1, a physiological substrate for PAK4. Suppression of PAK activity by amyloid-beta oligomers has been reported in Alzheimer's disease. Thus, PAKs may represent a target for various neurotoxic protein oligomers, and signaling deficits may contribute to the behavioral defects in chronic neurodegenerative diseases.
Danzer
Karin M
KM
Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany.
Schnack
Cathrin
C
Sutcliffe
Andrew
A
Hengerer
Bastian
B
Gillardon
Frank
F
D000818:Animals; D001933:Brain Stem / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000378:metabolism* / Q000494:pharmacology; D005260:Female; D002479:Inclusion Bodies / Q000378:metabolism; D054461:Lim Kinases / Q000378:metabolism; D046911:Macromolecular Substances / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009410:Nerve Degeneration / Q000378:metabolism / Q000503:physiopathology; D019636:Neurodegenerative Diseases / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D009474:Neurons / Q000378:metabolism*; D010766:Phosphorylation; D011108:Polymers / Q000378:metabolism; D040081:Protein Array Analysis; D051844:alpha-Synuclein / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D051846:beta-Synuclein / Q000378:metabolism / Q000494:pharmacology; D054462:p21-Activated Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
D004791:Enzyme Inhibitors; D046911:Macromolecular Substances; D011108:Polymers; D051844:alpha-Synuclein; D051846:beta-Synuclein; D054461:Lim Kinases; C492065:Pak4 protein, mouse; D054462:p21-Activated Kinases