Tyrosine residue 251 is critical for M6a-induced neuroplasticity

KARINA FORMOSO; ALBERTO CC FRASCH; CAMILA SCORTICATI

Cordoba

Congreso; XXVII Congreso Anual de la Sociedad Argentina de Investigaciones en Neurociencias; 2012

Sociedad Argentina de investigación en Neurociencias (SAN)

Neuronal glycoprotein M6a is involved in neuronal plasticity through unknown mechanisms. Recently a phosphorylated form at tyrosine(Y)251 has been found in the C-terminal region of M6a in mouse brain. Signaling phosphorylated proteins on tyrosine residues are specifically recognized by Src Homology 2 (SH2) modular protein interaction domains. Moreover, an in silico analysis showed that it could be a target of Src family of kinases. Therefore, the aim of this work is to establish how the phosphorylation state of Y251 is involved in neurite outgrowth and filopodia formation. To this end, we expressed Y251A-M6a (non-phosphorylatable) and Y251D-M6a (constitutively phosphorylated) in rat hippocampal neurons and cell lines and we quantified neurite outgrowth and filopodia formation. The results showed that in both primary culture of neurons and N2a cells the Y251A mutant failed to promote the formation and extension of neurites. In contrast, there are no significant differences in filopodia density in both neurons and Cos-7 cells, where all constructs showed the same ability to promote filopodium formation. Taken together, these results suggest that the Y251 residue of M6a contributes to the regulation of neurite outgrowth but not to filopodia formation. Although, this effect could be achieved by the interaction of Y251 residue with the SH2 domain of the Src kinases, further studies will be needed to prove this hypothesis.