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A role for centrin 3 in centrosome reproduction
S Middendorp1, T Küntziger, Y Abraham
1Institut Curie, Section Recherche, UMR 144 du CNRS, 75248 Paris Cedex 05, France.
The Journal of Cell Biology
|February 9, 2000
Summary
Human HsCEN3 protein inhibits centrosome duplication in Xenopus embryos and acts as a dominant negative mutant of yeast CDC31. This suggests conserved mechanisms for centrosome reproduction across species.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Centrosome duplication is crucial for bipolar cell division, yet its molecular mechanisms remain unclear.
- The Saccharomyces cerevisiae CDC31 gene is vital for spindle pole body (SPB) duplication, with its product belonging to the calmodulin superfamily.
Purpose of the Study:
- To functionally analyze the human centrin gene HsCEN3, a homolog of CDC31.
- To investigate the role of HsCEN3 in centrosome duplication and cell division.
Main Methods:
- Transient overexpression of wild-type and mutant HsCen3p in human cells.
- Injection of recombinant HsCen3p or its encoding RNA into Xenopus laevis embryos.
- Complementation analysis of HsCEN3 in S. cerevisiae CDC31 mutants.
Main Results:
- HsCen3p localization to centrioles requires a functional fourth EF-hand but does not cause mitotic defects in human cells.
- HsCen3p inhibits centrosome duplication and causes undercleavage in Xenopus embryos.
- HsCEN3 fails to complement S. cerevisiae CDC31 mutations but inhibits SPB duplication, acting as a dominant-negative mutant.
Conclusions:
- The human HsCEN3 protein interferes with conserved centrosome duplication pathways.
- HsCen3p likely functions by sequestering Cdc31p-binding proteins.
- Centrosome reproduction mechanisms are conserved across diverse species despite structural differences.