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Drosophila Ana2 is a conserved centriole duplication factor.

Stevens NR, Dobbelaere J, Brunk K, Franz A, Raff JW - J. Cell Biol. (2010)

Bottom Line: Functional orthologues of all but SAS-5 have been found in other species.Asl is now known to be essential for centriole duplication in flies, but no equivalent protein has been found in worms.We propose that members of the SAS-5/Ana2/STIL family of proteins are key conserved components of the centriole duplication machinery.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Gurdon Institute, Cambridge, England CB2 1QN, UK.

ABSTRACT
In Caenorhabditis elegans, five proteins are required for centriole duplication: SPD-2, ZYG-1, SAS-5, SAS-6, and SAS-4. Functional orthologues of all but SAS-5 have been found in other species. In Drosophila melanogaster and humans, Sak/Plk4, DSas-6/hSas-6, and DSas-4/CPAP-orthologues of ZYG-1, SAS-6, and SAS-4, respectively-are required for centriole duplication. Strikingly, all three fly proteins can induce the de novo formation of centriole-like structures when overexpressed in unfertilized eggs. Here, we find that of eight candidate duplication factors identified in cultured fly cells, only two, Ana2 and Asterless (Asl), share this ability. Asl is now known to be essential for centriole duplication in flies, but no equivalent protein has been found in worms. We show that Ana2 is the likely functional orthologue of SAS-5 and that it is also related to the vertebrate STIL/SIL protein family that has been linked to microcephaly in humans. We propose that members of the SAS-5/Ana2/STIL family of proteins are key conserved components of the centriole duplication machinery.

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Overexpression of Ana2 or Asl drives de novo formation of centriole-like structures. (A and B) Unfertilized eggs laid by UAS-Ana2-GFP (A) or UAS-Asl-GFP (B) mothers containing numerous MT asters (stained for tubulin). Arrows indicate the polar bodies. (C and D) Single asters from UAS-Ana2-GFP (C) or UAS-Asl-GFP (D) eggs stained for tubulin (blue) and DSas-4 (red). GFP is in green. Each aster contains several structures that stain for centriole markers. Bars: (A and B) 20 µm; (C and D) 2 µm.
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fig1: Overexpression of Ana2 or Asl drives de novo formation of centriole-like structures. (A and B) Unfertilized eggs laid by UAS-Ana2-GFP (A) or UAS-Asl-GFP (B) mothers containing numerous MT asters (stained for tubulin). Arrows indicate the polar bodies. (C and D) Single asters from UAS-Ana2-GFP (C) or UAS-Asl-GFP (D) eggs stained for tubulin (blue) and DSas-4 (red). GFP is in green. Each aster contains several structures that stain for centriole markers. Bars: (A and B) 20 µm; (C and D) 2 µm.

Mentions: GFP-Sak, GFP–DSas-6, and DSas-4–GFP share the unique ability to drive de novo formation of centriole-like structures in unfertilized eggs when highly overexpressed from the upstream activation sequence (UAS) promoter (Peel et al., 2007; Rodrigues-Martins et al., 2007b). UAS-GFP-Sak and UAS-GFP–DSas-6 induce these structures in ∼95% of unfertilized eggs, whereas UAS–DSas-4–GFP does so in ∼60% of unfertilized eggs (Peel et al., 2007). We wondered if we could use this assay to identify other components likely to function upstream in the centriole duplication pathway. We therefore generated transgenic lines carrying GFP fusions to all eight potential duplication factors under the control of the UAS promoter, which allowed us to overexpress them in unfertilized eggs (Fig. S1). Strikingly, only Ana2 (in 97% of eggs) and Asl (in 33% of eggs) were able to drive de novo formation of centriole-like structures (Fig. 1).


Drosophila Ana2 is a conserved centriole duplication factor.

Stevens NR, Dobbelaere J, Brunk K, Franz A, Raff JW - J. Cell Biol. (2010)

Overexpression of Ana2 or Asl drives de novo formation of centriole-like structures. (A and B) Unfertilized eggs laid by UAS-Ana2-GFP (A) or UAS-Asl-GFP (B) mothers containing numerous MT asters (stained for tubulin). Arrows indicate the polar bodies. (C and D) Single asters from UAS-Ana2-GFP (C) or UAS-Asl-GFP (D) eggs stained for tubulin (blue) and DSas-4 (red). GFP is in green. Each aster contains several structures that stain for centriole markers. Bars: (A and B) 20 µm; (C and D) 2 µm.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2819680&req=5

fig1: Overexpression of Ana2 or Asl drives de novo formation of centriole-like structures. (A and B) Unfertilized eggs laid by UAS-Ana2-GFP (A) or UAS-Asl-GFP (B) mothers containing numerous MT asters (stained for tubulin). Arrows indicate the polar bodies. (C and D) Single asters from UAS-Ana2-GFP (C) or UAS-Asl-GFP (D) eggs stained for tubulin (blue) and DSas-4 (red). GFP is in green. Each aster contains several structures that stain for centriole markers. Bars: (A and B) 20 µm; (C and D) 2 µm.
Mentions: GFP-Sak, GFP–DSas-6, and DSas-4–GFP share the unique ability to drive de novo formation of centriole-like structures in unfertilized eggs when highly overexpressed from the upstream activation sequence (UAS) promoter (Peel et al., 2007; Rodrigues-Martins et al., 2007b). UAS-GFP-Sak and UAS-GFP–DSas-6 induce these structures in ∼95% of unfertilized eggs, whereas UAS–DSas-4–GFP does so in ∼60% of unfertilized eggs (Peel et al., 2007). We wondered if we could use this assay to identify other components likely to function upstream in the centriole duplication pathway. We therefore generated transgenic lines carrying GFP fusions to all eight potential duplication factors under the control of the UAS promoter, which allowed us to overexpress them in unfertilized eggs (Fig. S1). Strikingly, only Ana2 (in 97% of eggs) and Asl (in 33% of eggs) were able to drive de novo formation of centriole-like structures (Fig. 1).

Bottom Line: Functional orthologues of all but SAS-5 have been found in other species.Asl is now known to be essential for centriole duplication in flies, but no equivalent protein has been found in worms.We propose that members of the SAS-5/Ana2/STIL family of proteins are key conserved components of the centriole duplication machinery.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Gurdon Institute, Cambridge, England CB2 1QN, UK.

ABSTRACT
In Caenorhabditis elegans, five proteins are required for centriole duplication: SPD-2, ZYG-1, SAS-5, SAS-6, and SAS-4. Functional orthologues of all but SAS-5 have been found in other species. In Drosophila melanogaster and humans, Sak/Plk4, DSas-6/hSas-6, and DSas-4/CPAP-orthologues of ZYG-1, SAS-6, and SAS-4, respectively-are required for centriole duplication. Strikingly, all three fly proteins can induce the de novo formation of centriole-like structures when overexpressed in unfertilized eggs. Here, we find that of eight candidate duplication factors identified in cultured fly cells, only two, Ana2 and Asterless (Asl), share this ability. Asl is now known to be essential for centriole duplication in flies, but no equivalent protein has been found in worms. We show that Ana2 is the likely functional orthologue of SAS-5 and that it is also related to the vertebrate STIL/SIL protein family that has been linked to microcephaly in humans. We propose that members of the SAS-5/Ana2/STIL family of proteins are key conserved components of the centriole duplication machinery.

Show MeSH
Related in: MedlinePlus