INVOLVEMENT OF ANNEXIN-II IN DNA-REPLICATION - EVIDENCE FROM CELL-FREE-EXTRACTS OF XENOPUS EGGS

Cell-free extracts of Xenopus eggs efficiently initiate and complete s emiconservative DNA replication of exogenously added plasmid DNA. DNA replication in such extracts can be neutralized by a monoclonal antibo dy (D1/274.5) against human annexin II. Specific immunodepletion of Xe nopus annexin II from the egg extracts results in loss of DNA replicat ive ability. Immunodepletion of annexin II does not prevent nuclear as sembly, a stringent requirement for DNA synthesis on exogenous DNA in this system. Replicative ability can be restored to the immunodepleted extracts by the addition of purified human annexin II. These results demonstrate that annexin II is involved in chromosomal DNA replication and has a role in the cell cycle of higher eukaryotes.