The murine telomerase catalytic subunit shares the PAb-240 mutant specific epitope of the p53 protein

Abstract

Many tumorigenic p53 mutants gain a common antigenic epitope that is recognized by the PAb-240 antibody. Database search identified the presence of this epitope in several other proteins, including several antibodies and the catalytic subunit of mouse telomerase, mTERT. These antibodies may represent a part of the previously demonstrated anti-idiotypic network built around p53. In the present study we demonstrate that the PAb-240 antibody was able to inhibit telomerase activity in extracts from both mouse and human tumor cells. The recognition of mTERT by PAb-240 is demonstrated by Western blotting and by using blocking peptides derived from mTERT. The existence of a shared epitope between mutant p53 and telomerase may suggest that the two proteins contribute to malignant transformation through a common pathway. © 2003 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.