title: Role of centrins 2 and 3 in organelle segregation and cytokinesis in Trypanosoma brucei.
abstract: Centrins are calcium binding proteins involved in cell division in eukaryotes. Previously, we have shown that depletion of centrin1 in Trypanosoma brucei (T. brucei) displayed arrested organelle segregation resulting in loss of cytokinesis. In this study we analyzed the role of T. brucei centrin2 (TbCen2) and T. brucei 3 (TbCen3) in the early events of T. brucei procyclic cell cycle. Both the immunofluorescence assay and electron microscopy showed that TbCen2 and 3-deficient cells were enlarged in size with duplicated basal bodies, multinuclei and new flagella that are detached along the length of the cell body. In both TbCen2 and TbCen3 depleted cells segregation of the organelles i.e. basal bodies, kinetoplast and nucleus was disrupted. Further analysis of the cells with defective organelle segregation identified three different sub configurations of organelle mis-segregations (Type 1-3). In addition, in majority of the TbCen2 depleted cells and in nearly half of the TbCen3 depleted cells, the kinetoplasts were enlarged and undivided. The abnormal segregations ultimately led to aborted cytokinesis and hence affected growth in these cells. Therefore, both centrin2 and 3 are involved in organelle segregation similar to centrin1 as was previously observed. In addition, we identified their role in kinetoplast division which may be also linked to overall mis-segregation.
authors.affiliation: Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, USA.
authors.forename: Angamuthu
authors.initials: A
authors.lastname: Selvapandiyan
authors.forename: Praveen
authors.initials: P
authors.lastname: Kumar
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Salisbury
authors.forename: Ching C
authors.initials: CC
authors.lastname: Wang
authors.forename: Hira L
authors.initials: HL
authors.lastname: Nakhasi
mesh_terms: D018797:Cell Cycle Proteins / Q000172:deficiency / Q000235:genetics*; D002467:Cell Nucleus / Q000648:ultrastructure; D048429:Cell Size; D002502:Centrioles / Q000235:genetics; D048749:Cytokinesis / Q000235:genetics*; D005407:Flagella / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D008854:Microscopy, Electron; D008938:Mitosis / Q000235:genetics; D015388:Organelles / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D015800:Protozoan Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D014346:Trypanosoma brucei brucei / Q000235:genetics* / Q000254:growth & development / Q000648:ultrastructure
chemical_list: D018797:Cell Cycle Proteins; D015800:Protozoan Proteins; D034741:RNA, Small Interfering