2018.07.02
Growth cone phosphoproteomics reveals that GAP-43 phosphorylated by JNK is a marker of axon growth and regeneration
（iScience. 2018 Jun 29;4:190-203. doi: 10.1016/j.isci.2018.05.019）
Kawasaki A1,2,10, Okada M1,2,3,10, Tamada A1,2,4,10,11, Okuda S5, Nozumi M1,2, Ito Y1, Kobayashi D1, Yamasaki T6,12, Yokoyama R7, Shibata T7, Nishina H6, Yoshida Y8, Fujii Y3, Takeuchi K1,2,9, Igarashi M1,2,13
1Department of Neurochemistry and Molecular Cell Biology, Graduate School of Medical and Dental Sciences, Niigata University
2Center for Trans-disciplinary Research, Institute for Research Promotion, Niigata University
3Department of Neurosurgery, Brain Research Institute, Niigata University
4Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency
5Laboratory of Bioinformatics, Graduate School of Medical and Dental Sciences, Niigata University
6Department of Developmental and Regenerative Biology, Medical Research Institute, Tokyo Medical and Dental University
7K.K. Sciex Japan
8Center for Coordination of Research, Institute for Research Promotion, Niigata University
9Department of Medical Cell Biology, Aichi Medical University
10These authors contributed equally
11Present address: Department of iPS Cell Applied Medicine, Kansai Medical University
12Present address: Department of Physiology, Keio University School of Medicine
13Lead Contact
Abstract
Neuronal growth cones are essential for nerve growth and regeneration, as well as for the formation and rearrangement of the neural network. To elucidate phosphorylation-dependent signaling pathways and establish useful molecular markers for axon growth and regeneration, we performed a phosphoproteomics study of mammalian growth cones, which identified >30,000 phosphopeptides of ~1,200 proteins. The phosphorylation sites were highly proline directed and primarily MAPK dependent, owing to the activation of JNK, suggesting that proteins that undergo proline-directed phosphorylation mediate nerve growth in the mammalian brain. Bioinformatics analysis revealed that phosphoproteins were enriched in microtubules and the cortical cytoskeleton. The most frequently phosphorylated site was S96 of GAP-43 (growth-associated protein 43-kDa), a vertebrate-specific protein involved in axon growth. This previously uncharacterized phosphorylation site was JNK dependent. S96 phosphorylation was specifically detected in growing and regenerating axons as the most frequent target of JNK signaling; thus it represents a promising new molecular marker for mammalian axonal growth and regeneration.
