AX3, a monoclonal antibody raised against isolated microtubule-organizing centers of Dictyostelium discoideum, stains microtubule-containing structures in species ranging from Dictyostelium to human. On immunoblots, the AX3 antibody recognizes heat-stable proteins in the 260- to 280-kDa molecular-mass range in a number of different species. The AX3 antigens from HeLa and embryonic mouse fibroblast cells coprecipitate with microtubules in vitro, indicating that these antigens are, indeed, MAPs. The AX3 antigens are not immunologically related to the mammalian MAP-2 or MAP-4 but are related to the 205-kDa MAP of Drosophila. This report describes a structural-type MAP in Dictyostelium and a MAP that is detected in a wide variety of species. The Drosophila 205-kDa MAP had previously been proposed to represent a member of the MAP-4 class of proteins. From the results reported here, however, it is suggested that proteins recognized by AX3 monoclonal antibody, including the Drosophila 205-kDa MAP, represent a distinct class of MAPs that has been widely conserved through evolution.
|Original language||English (US)|
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - 1992|
- Monoclonal antibody