Isolation of rat liver microtubule-associated proteins. Evidence for a family of microtubule-associated proteins with molecular mass of around 200,000 which distribute widely among mammalian cells.
Heat-stable microtubule-associated proteins (MAPs) were isolated from rat liver crude extract. The most prominent species showed a molecular mass close to that of bovine adrenal 190-kDa MAP (Kotani, S., Murofushi, H., Maekawa, S., Sato, C., and Sakai, H. (1986) Eur. J. Biochem. 156, 23-29), termed rat 190-kDa MAP. Immunological studies with antiserum against the rat 190-kDa MAP showed that this MAP exists in a variety of rat cells and tissues. The characteristics of the rat 190-kDa MAP, including molecular mass, heat stability, and distribution pattern, were very similar to those of bovine adrenal 190-kDa MAP. However, one-dimensional peptide mapping revealed considerable difference, and there is little mutual immunological cross-reactivity. We also identified in mouse neuroblastoma Neuro 2a cells a MAP of around 200 kDa which is considered to be MAP4 (Parysek, L. M., Asnes, C.F., and Olmsted, J.B. (1984) J. Cell Biol. 99, 1309-1315). MAP4 was slightly immunoreactive to both anti-(rat 190-kDa MAP) antiserum and anti-(bovine 190-kDa MAP) antiserum. Taking these results together, we conclude that mammalian tissues ubiquitously contain heat-stable MAPs of 200 kDa and that these 200-kDa MAPs should be considered as species-specific homologues.
Kotani
S
S
Department of Biophysics and Biochemistry, Faculty of Science, University of Tokyo, Japan.
Murofushi
H
H
Maekawa
S
S
Aizawa
H
H
Sakai
H
H
D000818:Animals; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D008099:Liver / Q000032:analysis*; D008869:Microtubule-Associated Proteins / Q000302:isolation & purification*; D008970:Molecular Weight; D009447:Neuroblastoma / Q000032:analysis; D051381:Rats
D008869:Microtubule-Associated Proteins