A cDNA for a human microtubule associated protein 2 epitope in the Alzheimer neurofibrillary tangle.

Microtubule associated protein 2 (MAP2) forms a long outward projection from the microtubule wall and is localized to the microtubule population of neuronal cell bodies and dendrites. In Alzheimer's disease, MAP2 epitopes are shared with the neurofibrillary tangle (NFT). Direct information about the molecular composition of the NFT can be obtained by cloning the genes for protein epitopes shared with NFT. Using two monoclonal antibodies to distinct MAP2 epitopes, one of which recognizes NFT, we screened a complex human fetal brain cDNA expression library constructed in lambda gt11. A 2.4 kilobase (kb) cDNA reacted with both antibodies independently. Northern blot analysis showed hybridization of the clone to a 9 kb RNA specific not only to brain but also to neurons. The DNA sequence of the cDNA will include the information for the MAP2 epitope contained in NFT.