Interaction of the microtubule-associated protein MAP-2c with Fyn, Grb2, and ERK2: Implications for a signaling cascade

摘要: MAP-2 belongs to the family of structural MAPs that binds microtubules and regulates cytoskeletal dynamics. All MAP-2 isoforms are developmentally regulated in the central nervous system, and contain functional domains that include the regulatory subunit of PKA and the repeats of the microtubule-binding-domain. Adjacent to the first repeat is the RTPPKSP motif for binding of SH3 domains. Transfections of MAP-2 cDNAs into COS7 cells, and incubation of cell lysates with SH3-GST fusion proteins determined that the strongest interaction was between MAP-2c and SH3-Fyn. ELISAs confirmed the binding of the SH3-domain of Fyn on the RTPPKSP motif on MAP-2c. A peptide containing the arginine to alanine mutation within the RTPPKSP motif abolished the interaction, confirming MAP-2 as a class I ligand for the SH3-domain of Fyn. A peptide containing a phosphorylated-threonine abolished the MAP-2/Fyn …