title: [A cytoskeletal protein with a molecular weight of 100 kD is a component of the endosomes participating in receptor-mediated endocytosis].
abstract: Our previous paper (Rodionov et al., 1985) reported production of monoclonal antibodies RN-17 reacting in cultured fibroblasts with a protein having a molecular weight of 100 kD. Immunofluorescence and immunoelectron microscopy showed that this protein was a component of microtubules, intermediate filaments and coated vesicles. We challenged a possibility whether these coated vesicles containing the 100 kD protein may take part in the receptor-mediated endocytosis. alpha 2-Macroglobulin conjugated with fluorescein isothiocyanate or 20 nm colloidal gold particles was used as a marker of the receptor-mediated endocytosis. Mouse embryo fibroblasts or Swiss 3T3 cells were incubated with labeled alpha 2 M, fixed and "stained" with DN-17 antibody, and the distribution of alpha 2 M and 100 kD protein was examined within the same cells. In both cell lines the endocytic vesicles contained 100 kD protein and alpha 2 M. Therefore 100 kD protein is a component of endocytic vesicles. Probably this protein mediates microtubule-dependent transport of endocytic vesicles in the cells.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000032:analysis*; D004705:Endocytosis; D011992:Endosomes / Q000648:ultrastructure*; D005455:Fluorescent Antibody Technique; D051379:Mice; D008854:Microscopy, Electron; D008970:Molecular Weight; D013194:Staining and Labeling / Q000379:methods; D000511:alpha-Macroglobulins / Q000032:analysis
chemical_list: D000911:Antibodies, Monoclonal; D003598:Cytoskeletal Proteins; D000511:alpha-Macroglobulins
vernacular_title: Tsitoskeletnyĭ belok s molekuliarnoĭ massoĭ 100 kDa iavliaetsia komponentom éndosom, uchastvuiushchikh v retseptor-oposredovannom éndotsitoze.