ApiLoc - A database of published protein sub-cellular localisation in Apicomplexa

version 3 (curated until May 28, 2011)

Centrins, cell cycle regulation proteins in human malaria parasite Plasmodium falciparum.

Mahajan, B., Selvapandiyan, A., Gerald, N. J., Majam, V., Zheng, H., Wickramarachchi, T., Tiwari, J., Fujioka, H., Moch, J. K., Kumar, N., Aravind, L., Nakhasi, H. L., Kumar, S. (2008 Nov 14, J Biol Chem)

Molecules and cellular mechanisms that regulate the process of cell division in malaria parasites remain poorly understood. In this study we isolate and characterize the four Plasmodium falciparum centrins (PfCENs) and, by growth complementation studies, provide evidence for their involvement in cell division. Centrins are cytoskeleton proteins with key roles in cell division, including centrosome duplication, and possess four Ca(2+)-binding EF hand domains. By means of phylogenetic analysis, we were able to decipher the evolutionary history of centrins in eukaryotes with particular emphasis on the situation in apicomplexans and other alveolates. Plasmodium possesses orthologs of four distinct centrin paralogs traceable to the ancestral alveolate, including two that are unique to alveolates. By real time PCR and/or immunofluorescence, we determined the expression of PfCEN mRNA or protein in sporozoites, asexual blood forms, gametocytes, and in the oocysts developing inside mosquito mid-gut. Immunoelectron microscopy studies showed that centrin is expressed in close proximity with the nucleus of sporozoites and asexual schizonts. Furthermore, confocal and widefield microscopy using the double staining with alpha-tubulin and centrin antibodies strongly suggested that centrin is associated with the parasite centrosome. Following the episomal expression of the four PfCENs in a centrin knock-out Leishmania donovani parasite line that exhibited a severe growth defect, one of the PfCENs was able to partially restore Leishmania growth rate and overcome the defect in cytokinesis in such mutant cell line. To our knowledge, this study is the first characterization of a Plasmodium molecule that is involved in the process of cell division. These results provide the opportunity to further explore the role of centrins in cell division in malaria parasites and suggest novel targets to construct genetically modified, live attenuated malaria vaccines.

PubMed: 18693242, full text

Localisation information

PFA0345w-b (CEN1) centrin-1

Experimental localisation: schizont, gametocyte, oocyst
  • Species: Plasmodium falciparum
  • Quote inferring localisation: "Asexual blood stage schizonts (A); gametocyte stage (B); and oocyst stage (C) P. falciparum parasites were probed against mouse anti-PfCEN1, -2, -3, and -4 antibodies."
  • Microscopy type: Light
  • Microscopy method: polyclonal antibody directly to protein
  • Strain: 3D7
  • Gene model mapping comments: MAL1P1.61 taken directly from paper, and this redirects to PFA0345, annotation matches
  • Localisation record: during schizont and gametocyte and oocyst

PF14_0443 (CEN2) centrin-2

Experimental localisation: area near nucleus during sporozoite, area near nucleus during schizont, schizont, gametocyte, oocyst
  • Species: Plasmodium falciparum
  • Quote inferring localisation: "In IEM, sections of sporozoites and asexual blood stage schizonts were incubated with anti-PfCEN2 antibody. In P. falciparum sporozoites, IEM localization of PfCEN2 was observed as multiple dots in an area surrounding the nucleus suggesting a possible association with the centrosome (Fig. 5A). Similarly, in blood form schizonts, immunogold particles were seen to be associated with an area in proximity to the nucleus (Fig. 5B)."
  • Microscopy type: EM, Light
  • Microscopy method: polyclonal antibody directly to protein
  • Strain: 3D7
  • Gene model mapping comments: Taken directly from paper
  • Localisation record: area near nucleus during sporozoite and schizont, during schizont and gametocyte and oocyst
  • Comment: centrosome

PF10_0271 (CEN3) centrin-3

Experimental localisation: nuclear membrane during schizont, area near nucleus during schizont, schizont, gametocyte, oocyst
  • Species: Plasmodium falciparum
  • Quote inferring localisation: "A careful three-dimensional visualization of the images confirmed that PfCEN3 reactivity is localized on the "outer" side and not "inside" of the central mass of the DAPI-stained DNA."
  • Microscopy type: Light
  • Microscopy method: polyclonal antibody directly to protein
  • Strain: 3D7
  • Gene model mapping comments: Taken directly from paper
  • Localisation record: nuclear membrane and area near nucleus during schizont, during schizont and gametocyte and oocyst
  • Comment: gene model inconsistent has been corrected in PlasmoDB

PF11_0066 (CEN4) centrin-4

Experimental localisation: schizont, gametocyte, oocyst
  • Species: Plasmodium falciparum
  • Quote inferring localisation: "Asexual blood stage schizonts (A); gametocyte stage (B); and oocyst stage (C) P. falciparum parasites were probed against mouse anti-PfCEN1, -2, -3, and -4 antibodies."
  • Microscopy type: Light
  • Microscopy method: polyclonal antibody directly to protein
  • Strain: 3D7
  • Gene model mapping comments: Taken directly from paper
  • Localisation record: during schizont and gametocyte and oocyst
  • Comment: gene model inconsistent has been corrected in PlasmoDB

PFI0875w (grp, Hsp70-2, BiP) heat shock protein 70

Experimental localisation: endoplasmic reticulum
  • Species: Plasmodium falciparum
  • Quote inferring localisation: "To confirm that PfCEN3 localizes to centrosomes in the nuclear membrane, parasite ER/nuclear membrane was stained with anti-BiP antibody, which labels an ER resident protein."
  • Microscopy type: Light
  • Microscopy method: polyclonal antibody directly to protein
  • Strain: 3D7
  • Gene model mapping comments: inferred from another publication
  • Localisation record: ER

PFI0180w (A-tubulin) alpha tubulin 1

Experimental localisation: mitotic spindle in nucleus during schizont, microtubule during schizont
  • Species: Plasmodium falciparum
  • Quote inferring localisation: "Wide field and three-dimensional confocal microscopy show that the prominent tubulin structures are enclosed within the nuclear membrane and that these microtubules extend into the nuclear DNA (Fig. 6D). These results are in agreement with previous studies (7, 8, 52), and it is reasonable to infer that the anti--tubulin reactivity inside the parasite nucleus indeed labels the mitotic spindle."
  • Microscopy type: Light
  • Microscopy method: polyclonal antibody directly to protein
  • Strain: 3D7
  • Gene model mapping comments: annotation matches
  • Localisation record: mitotic spindle in nucleus and microtubules during schizont