title: The Caenorhabditis elegans centrosomal protein SPD-2 is required for both pericentriolar material recruitment and centriole duplication.
abstract: BACKGROUND
  The centrosome is composed of a centriole pair and pericentriolar material (PCM). By marking the site of PCM assembly, the centrioles define the number of centrosomes present in the cell. The PCM, in turn, is responsible for the microtubule (MT) nucleation activity of centrosomes. Therefore, in order to assemble a functional bipolar mitotic spindle, a cell needs to control both centriole duplication and PCM recruitment. To date, however, the molecular mechanisms that govern these two processes still remain poorly understood.
  
  
  RESULTS
  Here we show that SPD-2 is a novel component of the C. elegans centrosome. SPD-2 localizes to the centriole throughout the cell cycle and accumulates on the PCM during mitosis. We show that SPD-2 requires SPD-5 for its accumulation on the PCM and that in the absence of SPD-2, centrosome assembly fails. We further show that centriole duplication is also defective in spd-2(RNAi) embryos, but not in spd-5(RNAi) embryos, where PCM recruitment is efficiently blocked.
  
  
  CONCLUSIONS
  Taken together, our results suggest that SPD-2 may link PCM recruitment and centriole duplication in C. elegans. SPD-2 shares homology with a human centrosome protein, suggesting that this key component of the C. elegans centrosome is evolutionarily conserved.
authors.affiliation: Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany. pelletie@mpi-cbg.de
authors.forename: Laurence
authors.initials: L
authors.lastname: Pelletier
authors.forename: Nurhan
authors.initials: N
authors.lastname: Ozlü
authors.forename: Eva
authors.initials: E
authors.lastname: Hannak
authors.forename: Carrie
authors.initials: C
authors.lastname: Cowan
authors.forename: Bianca
authors.initials: B
authors.lastname: Habermann
authors.forename: Martine
authors.initials: M
authors.lastname: Ruer
authors.forename: Thomas
authors.initials: T
authors.lastname: Müller-Reichert
authors.forename: Anthony A
authors.initials: AA
authors.lastname: Hyman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000378:metabolism; D002502:Centrioles / Q000502:physiology*; D018385:Centrosome / Q000502:physiology*; D019295:Computational Biology; D017931:DNA Primers; D004625:Embryo, Nonmammalian / Q000648:ultrastructure; D049452:Green Fluorescent Proteins; D007150:Immunohistochemistry; D008164:Luminescent Proteins; D008780:Methyltransferases; D008854:Microscopy, Electron; D008870:Microtubules / Q000378:metabolism; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D029742:Caenorhabditis elegans Proteins; D018797:Cell Cycle Proteins; D017931:DNA Primers; D008164:Luminescent Proteins; C486131:SPD-2 protein, C elegans; D049452:Green Fluorescent Proteins; C490112:pcm-1 protein, C elegans; D008780:Methyltransferases