Human Mps1 protein kinase is required for centrosome duplication and normal mitotic progression.
The mitotic spindle is essential for the maintenance of genetic stability, and in budding yeast its assembly and function depend on the Mps1 protein kinase. Mps1p is required for centrosome duplication and the spindle checkpoint. Several recent reports demonstrate that vertebrate Mps1 proteins regulate the spindle checkpoint, but reports conflict regarding their role in centrosome duplication. Here we provide multiple lines of evidence that the human Mps1 protein (hMps1) is required for centrosome duplication. A recently described rabbit polyclonal antibody against hMps1 specifically recognizes centrosomes in a variety of human cell types. Overexpression of a dominant-negative version of hMps1 (hMps1KD) can prevent centrosome duplication in a variety of cell types, and active hMps1 accelerates centrosome reduplication in U2OS cells. Finally, we demonstrate that disruption of hMps1 function with pools of hMps1-specific small interfering RNAs causes a pleiotropic phenotype resulting from the combination of severe mitotic abnormalities and failures in centrosome duplication. This approach demonstrates that hMps1 is required for centrosome duplication and for the normal progression of mitosis, and suggests that the threshold level of hMps1 function required for centrosome duplication is lower than that required for hMps1 mitotic functions.
Fisk
Harold A
HA
Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309-0347, USA.
Mattison
Christopher P
CP
Winey
Mark
M
D018797:Cell Cycle Proteins; D002460:Cell Line; D045744:Cell Line, Tumor; D018385:Centrosome / Q000648:ultrastructure; D019084:Fluorescent Antibody Technique, Indirect; D005799:Genes, Dominant; D005982:Glutathione Transferase / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D008164:Luminescent Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008938:Mitosis; D010641:Phenotype; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000502:physiology*; D034741:RNA, Small Interfering / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014162:Transfection
D018797:Cell Cycle Proteins; D008164:Luminescent Proteins; D034741:RNA, Small Interfering; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D005982:Glutathione Transferase; D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; C075840:TTK protein, human; D010744:Phosphoric Monoester Hydrolases