Factors controlling the appearance of the immunofluorescent nuclear dots revealed with monoclonal antibody against microtubule-associated protein-1.
A monoclonal antibody raised against microtubule-associated protein-1 (MAP-1) binds to nuclei of normal human fibroblasts, its binding site being detected as intranuclear immunofluorescent dots. The percentage of cells showing these dots increased with insulin, hydrocortisone, epidermal growth factor (EGF), and transferrin in serum-free medium, their effects decreasing in this order. The appearance of dots induced by serum or insulin plus hydrocortisone was dependent on the Ca2+ concentration of the medium. The Ca2+ ionophore A23187 increased the rate of appearance of cells containing dots. Conversely, the calmodulin inhibitor W-7 blocked their appearance and decreased the number of cells containing dots. The dose-response curves of W-7 for inhibition of the appearance of dots and of DNA synthesis were essentially identical. These results suggest that the appearance of intranuclear MAP-1 antigen is controlled mainly by insulin, Ca2+ and calmodulin and is associated with DNA replication.
D000911:Antibodies, Monoclonal; D001769:Blood; D002118:Calcium / Q000494:pharmacology; D002467:Cell Nucleus / Q000187:drug effects; D005260:Female; D005455:Fluorescent Antibody Technique; D006133:Growth Substances / Q000494:pharmacology; D006728:Hormones / Q000494:pharmacology; D006801:Humans; D008168:Lung / Q000166:cytology* / Q000196:embryology; D008869:Microtubule-Associated Proteins / Q000032:analysis*; D011247:Pregnancy
D000911:Antibodies, Monoclonal; D006133:Growth Substances; D006728:Hormones; D008869:Microtubule-Associated Proteins; D002118:Calcium