A general term for a heterogeneous set of proteins that share the property of being associated with microtubules. Some contribute to the electron-lucent zone that surrounds microtubules in EM pictures. MAP1A (2805 aa) and 1B (2468 aa) and MAP2A and 2B (1827 aa) form projections from brain microtubules. MAP2 is characteristic of axonal processes of vertebrate nerve cells and distinguishes them from dendritic processes. MAP4 (1152 aa) copurifies with MAP1 and MAP2 and is found in many tissues. MAP1C is a microtubule associated motor protein with two heavy chains (cytoplasmic dynein 1 heavy chain, 4646 aa; CD2HC, 4307 aa) associated with six or seven light and intermediate chains of about 350–500 aa, the two-headed cytoplasmic equivalent of ciliary dynein responsible for retrograde transport (transport towards the centrosome). NB Not to be confused with mitogen activated protein kinases (MAP kinases).
Subjects: Medicine and Health — Chemistry.