Trypanosome Prereplication Machinery Contains a Single Functional Orc1/Cdc6 Protein, Which Is Typical of Archaea

Autor(es)

de Melo Godoy, Patricia Diogo ^[1] ; Nogueira-Junior, Luis Antonio ^[1] ; Paes, Lisvane S. ^[2] ; Cornejo, Alberto ^[3] ; Martins, Rafael Miyazawa ^[3] ; Silber, Ariel M. ^[2] ; Schenkman, Sergio ^[3] ; Elias, M. Carolina ^[1]

Afiliação do(s) autor(es)

^[1] Inst Butantan, Parasitol Lab, BR-05503900 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Dept Parasitol, Sao Paulo - Brazil

^[3] Univ Fed Sao Paulo, Dept Microbiol Imunol & Parasitol, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Eukaryotic Cell; v. 8, n. 10, p. 1592-1603, OCT 2009.
• Citações Web of Science: 42

Resumo

In unicellular eukaryotes, such as Saccharomyces cerevisiae, and in multicellular organisms, the replication origin is recognized by the heterohexamer origin recognition complex (ORC) containing six proteins, Orc1 to Orc6, while in members of the domain Archaea, the replication origin is recognized by just one protein, Orc1/Cdc6; the sequence of Orc1/Cdc6 is highly related to those of Orc1 and Cdc6. Similar to Archaea, trypanosomatid genomes contain only one gene encoding a protein named Orc1. Since trypanosome Orc1 is also homologous to Cdc6, in this study we named the Orc1 protein from trypanosomes Orc1/Cdc6. Here we show that the recombinant Orc1/Cdc6 from Trypanosoma cruzi (TcOrc1/Cdc6) and from Trypanosoma brucei (TbOrc1/Cdc6) present ATPase activity, typical of prereplication machinery components. Also, TcOrc1/Cdc6 and TbOrc1/Cdc6 replaced yeast Cdc6 but not Orc1 in a phenotypic complementation assay. The induction of Orc1/Cdc6 silencing by RNA interference in T. brucei resulted in enucleated cells, strongly suggesting the involvement of Orc1/Cdc6 in DNA replication. Orc1/Cdc6 is expressed during the entire cell cycle in the nuclei of trypanosomes, remaining associated with chromatin in all stages of the cell cycle. These results allowed us to conclude that Orc1/Cdc6 is indeed a member of the trypanosome prereplication machinery and point out that trypanosomes carry a prereplication machinery that is less complex than other eukaryotes and closer to archaea. (AU)

• Processo FAPESP: 05/00154-1 - Identificação das origens e da maquinária de replicação em células de Trypanosoma
• Beneficiário: Maria Carolina Quartim Barbosa Elias Sabbaga
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 03/13257-8 - Clonagem e caracterização de transportadores de aminoácidos em Trypanosoma cruzi: uma abordagem pós-genômica
• Beneficiário: Ariel Mariano Silber
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores