Monoclonal antibody CC-3 recognizes phosphoproteins in interphase and mitotic cells.
Among a library of monoclonal antibodies (mAbs) recognizing developmental markers in the chick embryo, mAb CC-3 was selected because of its differential immunostaining of mitotic cells. The intracellular distribution of the CC-3 antigen (CC-3a) throughout the cell cycle was visualized by immunolocalization. In interphase cells CC-3a resided in the nucleus and was arranged in distinct extranucleolar clusters. At prophase, the nuclear reactivity of CC-3a considerably increased and subsequently extended to the cytoplasm at metaphase. From metaphase through anaphase, most of the reactivity was associated with the mitotic apparatus. During cytokinesis CC-3a was detected in the mid-body and also in discrete speckles dispersed throughout the cytoplasm. The initial interphase pattern was then restored in the two daughter nuclei. Immunoblot analysis demonstrated that a 255-kDa phosphoprotein was present only in the interphase nucleus and that a complete new set of phosphoproteins accounted for the mitotic cell reactivity. The binding of CC-3 was dependent on the phosphorylation of its antigens. CC-3a is an evolutionary conserved molecule; it is present in such phylogenetically distant species as Drosophila and humans. Furthermore, the unique behavior of CC-3 on sections of normal, embryonic, and regenerative tissue and in cell culture immunostaining make it a reliable tool to identify mitotic foci.
Thibodeau
A
A
Ontogenèse et Génétique Moléculaire, Centre de recherche du CHUL, Sainte-Foy, Québec, Canada.
Vincent
M
M
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D002451:Cell Compartmentation; D002460:Cell Line; D002642:Chick Embryo; D005455:Fluorescent Antibody Technique; D066298:In Vitro Techniques; D007399:Interphase; D008938:Mitosis; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000737:chemistry / Q000276:immunology*; D010750:Phosphoproteins / Q000737:chemistry / Q000276:immunology*; D013045:Species Specificity; D008941:Spindle Apparatus / Q000737:chemistry / Q000276:immunology*
D000911:Antibodies, Monoclonal; D009687:Nuclear Proteins; D010750:Phosphoproteins