Scientific Publications by FDA Staff

J Biol Chem 2004 Jun 11;279(24):25703-10

Centrin gene disruption impairs stage specific basal body duplication and cell cycle progression in Leishmaniac.

Selvapandiyan A, Debrabant A, Duncan R, Muller J, Salotra P, Sreenivas G, Salisbury JL, Nakhasi HL

Nakhasi HL, US FDA, Ctr Biol Evaluat & Res, Off Blood Res & Review, Div Emerging & Transfus Transmitted Dis,Lab Bacter, Bldg 29,Rm 222,8800 Rockville Pike, Bethesda, MD 20892 USA US FDA, Ctr Biol Evaluat & Res, Off Blood Res & Review, Div Emerging & Transfus Transmitted Dis,Lab Bacter, Bethesda, MD 20892 USA US FDA, Ctr Biol Evaluat & Res, Off Vaccines Res & Review, Div Viral Prod,Lab Vector Borne Dis, Bethesda, MD 20892 USA Safdarjang Hosp, Indian Council Med Res, Inst Pathol, New Delhi 110029, India Mayo Clin, Coll Med, Tumor Biol Program, Rochester, MN 55905 USA

Centrin is a calcium binding cytoskeletal protein involved in duplication of centrosomes in higher eukaryotes. In order 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 G2/M stage. The axenic amastigotes also showed failure of basal body duplication and failure of cytokinesis resulting in multinucleated large cells. Increased TUNEL positivity was observed in centrin mutant axenic amastigotes compared to 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.