Interactions of adaptor protein Grb2 with microtubule associated protein 2c

J. Plucarová^1,2, S. Jansen¹, A. Laníková^1,2 , L. Žídek^1,2

¹Central European Institute of Technology (CEITEC), Faculty of Science, Masaryk University, Kamenice 735/5, Brno, Czech Republic

²National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 735/5, Brno, Czech Republic

plucarova.jitka@mail.muni.cz

MAP2/Tau is a family of neuronal structural microtubule associated proteins (MAPs) known for their ability to bind and stabilize microtubules. Microtubule associated protein 2c (MAP2c) is the shortest isoform of MAP2 that is expressed in neurons of developing brain and brain regions that retain neuronal plasticity in adulthood [1]. Besides binding to tubulin, MAP2c also interacts with proteins involved in signal transduction pathways, such as Grb2 [2], which is an adaptor protein involved in the Ras/Raf/MEK/ERK signaling cascade that is associated with the cell proliferation and apoptosis regulation [3]. Grb2 was reported to bind MAP2c through its SH3 domains [2] but the interaction was not characterized in a residue-specific manner. Therefore, we investigated the interaction of MAP2c with Grb2 using solution NMR. We acquired HNCO spectra to identify residues of MAP2c involved in the interaction with Grb2. The interactions of MAP2c with its binding partners, including Grb2, are regulated both by serine/threonine and tyrosine phosphorylation [2, 4]. Therefore, we employed NMR to investigate the influence of MAP2c phosphorylation by serine/threonine kinases PKA and ERK2 and tyrosine kinase Fyn on this interaction.

The results will help to elucidate the involvement of MAP2c in the signal transduction pathways and the regulation of its interactions with relevant binding partners by serine/threonine and tyrosine kinases.

1. Viereck, Christopher, Richard P. Tucker, and Andrew Matus. "The adult rat olfactory system expresses microtubule-associated proteins found in the developing brain." Journal of Neuroscience 9.10 (1989): 3547-3557.

2. Lim, Rita WL, and Shelley Halpain. "Regulated association of microtubule-associated protein 2 (MAP2) with Src and Grb2: evidence for MAP2 as a scaffolding protein." Journal of Biological Chemistry 275.27 (2000): 20578-20587.

3. McCubrey, James A., et al. "Roles of the Raf/MEK/ERK pathway in cell growth, malignant transformation and drug resistance." Biochimica et Biophysica Acta (BBA)-Molecular Cell Research 1773.8 (2007): 1263-1284.

4. Zamora-Leon, S. Pilar, et al. "Fyn phosphorylates human MAP-2c on tyrosine 67." Journal of Biological Chemistry 280.3 (2005): 1962-1970.

This work was supported by Czech Science Foundation (project 20-12669S).