Identification of a novel 80 kDa antigen associated with cell proliferation

Exploiting the immunomasking method, a polyclonal antibody has been developed in mice for identification of a novel 80 kDa antigen (P80) in KB cells. The P80 was not detected in normal resting cells but was present in appreciable amount in malignant cells. In a comparative Western transfer the antisera to the immune complexes identified a 80 kDa peptide absent in normal cell extracts. When growth of KB cells were arrested by 48 h of serum starvation the P80 was not detected but after refeeding with serum containing medium, the P80 reappeared within 1 h. This result indicates that the P80 is associated with cell proliferation and appears early in the GI-S phase of the cell cycle.