Single molecule analysis of Trypanosoma brucei DNA replication dynamics

Author(s)

Calderano, Simone Guedes ^{[1, 2]} ; Drosopoulos, William C. ^[3] ; Quaresma, Marina Monaco ^{[1, 2]} ; Marques, Catarina A. ^[4] ; Kosiyatrakul, Settapong ^[3] ; McCulloch, Richard ^[4] ; Schildkraut, Carl L. ^[3] ; Elias, Maria Carolina ^{[1, 2]}

Affiliation

^[1] Inst Butantan, Lab Especial Ciclo Celular, BR-05503900 Sao Paulo, SP - Brazil

^[2] Inst Butantan, Ctr Toxins Immune Response & Cell Signaling CeTIC, BR-05503900 Sao Paulo, SP - Brazil

^[3] Albert Einstein Coll Med, Dept Cell Biol, Bronx, NY 10461 - USA

^[4] Univ Glasgow, Wellcome Trust Ctr Mol Parasitol, Coll Med Vet & Life Sci, Inst Infect Immun & Inflammat, Glasgow G12 8TA, Lanark - Scotland

• Document type: Journal article
• Source: Nucleic Acids Research; v. 43, n. 5, p. 2655-2665, MAR 11 2015.
• Web of Science Citations: 13

Abstract

Eukaryotic genome duplication relies on origins of replication, distributed over multiple chromosomes, to initiate DNA replication. A recent genomewide analysis of Trypanosoma brucei, the etiological agent of sleeping sickness, localized its replication origins to the boundaries of multigenic transcription units. To better understand genomic replication in this organism, we examined replication by single molecule analysis of replicated DNA. We determined the average speed of replication forks of procyclic and bloodstream form cells and we found that T. bru-cei DNA replication rate is similar to rates seen in other eukaryotes. We also analyzed the replication dynamics of a central region of chromosome 1 in procyclic forms. We present evidence for replication terminating within the central part of the chromosome and thus emanating from both sides, suggesting a previously unmapped origin toward the 5' extremity of chromosome 1. Also, termination is not at a fixed location in chromosome 1, but is rather variable. Importantly, we found a replication origin located near an ORC1/CDC6 binding site that is detected after replicative stress induced by hydroxyurea treatment, suggesting it may be a dormant origin activated in response to replicative stress. Collectively, our findings support the existence of more replication origins in T. brucei than previously appreciated. (AU)

• FAPESP's process: 13/07467-1 - CeTICS - Center of Toxins, Immune-Response and Cell Signaling
• Grantee: Hugo Aguirre Armelin
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 11/21570-4 - DNA replication in trypanosome: characterization of DNA replication forks and identification of DNA replication origins in Trypanosoma brucei
• Grantee: Maria Carolina Quartim Barbosa Elias Sabbaga
• Support Opportunities: Regular Research Grants
• FAPESP's process: 12/24554-2 - Conflict between replication and transcription: analysis of the replication fork in Trypanosoma brucei cells that present the transcription machinery stagnant in the genome
• Grantee: Marina Monaco Quaresma
• Support Opportunities: Scholarships in Brazil - Scientific Initiation