title: Monoclonal antibody to intermediate filament antigen cross-reacts with higher plant cells.
abstract: The monoclonal antibody (anti-IFA) raised (Pruss et al., 1981, Cell 27:419-428) against an intermediate filament antigen, which is widespread throughout phylogeny, has been shown here to cross-react with higher plants. On immunoblotting, anti-IFA cross-reacted with proteins in homogenates of carrot suspension cells and of meristematic cells from onion root tips. A 50-kD cross-reactive protein was enriched in a fraction that consisted of detergent-insoluble bundles of 7-nm fibrils from carrot protoplasts (Powell et al., 1982, J. Cell Sci. 56:319-335). By use of indirect immunofluorescence, anti-IFA stained formaldehyde-fixed onion meristematic cells and carrot protoplasts in patterns approximating those obtained with monoclonal anti-tubulins. That anti-IFA was not recognizing plant tubulins was established by use of immunoblots of two-dimensional gels on which the proteins that comprised isolated fibrillar bundles and taxol-purified carrot tubulins had been separated. The two groups of proteins had different positional coordinates: anti-IFA recognized the fibrillar bundle proteins, and anti-tubulins recognized plant microtubule proteins with no cross-reaction to the heterologous proteins. Likewise, formaldehyde-fixed taxol microtubules from carrot cells could be stained with anti-tubulin but not with anti-IFA. It is concluded that an epitope common to intermediate filaments from animals co-distributes with microtubules in higher plant cells.
authors.forename: P J
authors.initials: PJ
authors.lastname: Dawson
authors.forename: J S
authors.initials: JS
authors.lastname: Hulme
authors.forename: C W
authors.initials: CW
authors.lastname: Lloyd
mesh_terms: D003429:Cross Reactions; D000939:Epitopes; D005455:Fluorescent Antibody Technique; D007381:Intermediate Filament Proteins / Q000276:immunology*; D007526:Isoelectric Point; D008970:Molecular Weight; D010944:Plants / Q000276:immunology*
chemical_list: D000939:Epitopes; D007381:Intermediate Filament Proteins