PROSITE documentation PDOC00201

Tau and MAP proteins tubulin-binding repeat signature and profile

Microtubules consist of tubulins as well as a group of additional proteins collectively known as the Microtubule Associated Proteins (MAP). MAP's have been classified into two classes: high molecular weight MAP's and Tau protein. These proteins promote microtubule assembly and stabilize microtubules. The C-terminal region of a subset of these proteins contains three or four tandem repeats of a conserved domain of about thirty amino acid residues which is implicated in tubulin-binding and which seems to have a stiffening effect on microtubules. The proteins currently known to contain such repeats are:

• Tau [1], from neurones.
• MAP2 [2], a neuronal member of the high molecular weight MAP's.
• MAP4 [3], a non-neuronal member of the high molecular weight MAP's. MAP4 is is also expressed in some neurons.

The pattern we developed to detect this repeated region spans the last thirteen residues of the repeated region. We also developed a profile which covers the entire repeat.