title: Centrin gene disruption impairs stage-specific basal body duplication and cell cycle progression in Leishmania.
abstract: Centrin is a calcium-binding cytoskeletal protein involved in the duplication of centrosomes in higher eukaryotes. To explore the role of centrin in the protozoan parasite Leishmania, we created Leishmania deficient in the centrin gene (LdCEN). Remarkably, centrin null mutants (LdCEN(-/-)) showed selective growth arrest as axenic amastigotes but not as promastigotes. Flow cytometry analysis confirmed that the mutant axenic amastigotes have a cell cycle arrest at the G(2)/M stage. The axenic amastigotes also showed failure of basal body duplication and failure of cytokinesis resulting in multinucleated "large" cells. Increased terminal deoxy uridine triphosphate nick end labeling positivity was observed in centrin mutant axenic amastigotes compared with wild type cells, suggesting the activation of a programmed cell death pathway. Growth of LdCEN(-/-) amastigotes in infected macrophages in vitro was inhibited and also resulted in large multinucleated parasites. Normal basal body duplication and cell division in the LdCEN knockout promastigote is unique and surprising. Further, this is the first report where disruption of a centrin gene displays stage-specific/cell type-specific failure in cell division in a eukaryote. The centrin null mutant defective in amastigote growth could be useful as a vaccine candidate against leishmaniasis.
authors.affiliation: Division of Emerging and Transfusion Transmitted Diseases, Office of Blood Research and Review, Food and Drug Administration, Bethesda, MD 20892, USA.
authors.forename: Angamuthu
authors.initials: A
authors.lastname: Selvapandiyan
authors.forename: Alain
authors.initials: A
authors.lastname: Debrabant
authors.forename: Robert
authors.initials: R
authors.lastname: Duncan
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Muller
authors.forename: Poonam
authors.initials: P
authors.lastname: Salotra
authors.forename: Gannavaram
authors.initials: G
authors.lastname: Sreenivas
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Salisbury
authors.forename: Hira L
authors.initials: HL
authors.lastname: Nakhasi
mesh_terms: D000818:Animals; D017209:Apoptosis; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000502:physiology*; D002453:Cell Cycle; D002455:Cell Division; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000502:physiology*; D007891:Leishmania / Q000254:growth & development*; D008264:Macrophages / Q000469:parasitology
chemical_list: D002135:Calcium-Binding Proteins; D002868:Chromosomal Proteins, Non-Histone; C056608:caltractin