Abstract
Monoclonal antibodies reactive to a high molecular weight pro-tein in MDBK cells were prepared and used to localize this protein in cultured cells. An insoluble fraction of MDBK cells after extraction with Triton X-100 was used as an immunogen and an immunofluorescent cell staining method was used to screen hybridoma cells. Three mAbs recognized a protein having nearly the same mobility as that of the microtubule-associated protein 2 in SDS-PAGE but no immunological reactivity of bovine microtubule proteins to these mAbs distinguished these proteins. Immunoblotting and cell staining experiments showed its presence in the intermediate filament-nuclear matrix fraction. Dou-ble staining experiments of cells using these mAbs and antibody against vimen-tin cleared the association of this protein with vimentin filaments. Results of im-munoelectron microscopy confirmed its localization on the intermediate filaments.
