Microtubule-associated protein 2

The proteins of this family were originally isolated since they copurify with tubulin in polymerization experiments: tubulin in cell extracts can be made to polymerize to produce microtubules (MT) under the influence of heat and the addition of GTP, and the MT can then be collected by centrifugation.

When this is done a series of microtubule associated proteins are collected along with the MT and can be detected by SDS-PAGE and other methods.

[7] All forms of MAP2 share a common core sequence which includes MT binding domains, 18 amino acid sequences which are found in other MT associated proteins such as MAP Tau and MAP1B.

The MAP2 isoforms are thought to be involved in MT assembly, which is an essential step in neuritogenesis.

As a result antibodies to MAP2 are widely used to identify neuronal cells and trace dendritic processes in experimental contexts.

Neurons were grown in tissue culture and stained with antibody to MAP2 protein in green and MAP tau in red using the immunofluorescence technique. MAP2 is found only in dendrites and perikarya, while tau is found not only in the dendrites and perikarya but also in axons. As a result, axons appear red while the dendrites and perikarya appear yellow, due to superimposition of the red and green signals. DNA is shown in blue using the DAPI stain which highlights the nuclei. Image courtesy EnCor Biotechnology Inc .