|MadSci Network: Molecular Biology|
Tau and MAP2 are both microtubule associated proteins that are expressed primarily in neurons. Within neurons, tau is localized predominately in axons, while MAP2 is specifically localized to dendrites. They both contain a C-terminal microtubule-binding region characterized by imperfect tandem repeats. This microtuble-binding region is highly conserved between MAP2 and tau, with 60-70% sequence similarity. However, the N-terminal regions (called "projection domains" as they are thought to project out from the surface of the microtubule) differ greatly between the two proteins and probably serve different functions in each protein. The association of both MAP2 and tau with microtubules is regulated in part by phosphorylation. In general, phosphorylation decreases the affinity of the MAPs for microtubules. MAP2 and tau are phosphorylated by many of the same kinases, including CDK5, MARK, PKA and GSK3-beta. Therefore, substances that activated any of these kinases would be likely to lead to hyperphosphorylation of both MAP2 and tau. * Wiche, G., Oberkanins, C. & Himmler, A. (1991) Molecular structure and function of microtubule-associated proteins. Int. Rev. Cytol. 124: 217-273. * Cassimeris L, Spittle C. (2001) Regulation of microtubule-associated proteins. Int Rev Cytol. 210:163-226. Dmitri Leonoudakis with help from Janis Bunker
Try the links in the MadSci Library for more information on Molecular Biology.