ORC1/CDC6 and MCM7 distinct associate with chromatin through Trypanosoma cruzi life cycle

- The component of pre-replication complex TcORC1/CDC6 does not bind DNA in non-replicative stages of Trypanosoma cruzi life cycle.
- The other component of the pre-replication complex TcMCM7 is not expressed in non-replicative stages of the T. cruzi life cycle.
- We provide possible molecular basis for the lack of DNA replication in non-proliferative stages.

Trypanosoma cruzi alternates between replicative and non-replicative stages. We analyzed the expression of components of the pre-replication machinery TcORC1/CDC6 and TcMCM7 and their interaction with DNA in all T. cruzi stages. TcORC1/CDC6 remains in the nuclear space during all stages of the life cycle and interacts with DNA in the replicative stages; however, it does not bind to DNA in the non-replicative forms. Moreover, TcMCM7 is not present in the non-replicative stages. These data suggest that the lacking of DNA replication during the T. cruzi life cycle may be a consequence of the blocking of TcORC1/CDC6-DNA interaction and of the down regulation of the TcMCM7 expression.

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