Microtubules are associated with a family of proteins called microtubule associated proteins (MAPs), which includes the protein tau and a group of proteins referred to as MAP1, MAP2, MAP3, MAP4, and MAP5. MAP2 is made up of two ~280kDa apparent molecular weight bands referred to as MAP2a and MAP2b. A third lower molecular weight form, usually called MAP2c, corresponds to a pair of protein bands running at ~70kDa on SDS-PAGE gels. All these MAP2 forms are derived from a single gene by alternate transcription, and all share a C-terminal sequence which includes either three or four microtubule-binding peptide sequences, which are very similar to those found in the related microtubule binding protein tau.
This antibody was raised against recombinant human “projection domain”, amino acids 377-1505; which are expressed in MAP2A and MAP2B. MAP2 isoforms are expressed only in neuronal cells and specifically in perikarya and dendrites of neurons; therefore, MAP2 makes an excellent marker for neuronal cells. MAP2A and MAP2B isoforms are expressed later in neuronal development than MAP2C and MAP2D.