Inhibition of centrosome protein assembly leads to p53-dependent exit from the cell cycle.
Previous evidence has indicated that an intact centrosome is essential for cell cycle progress and that elimination of the centrosome or depletion of individual centrosome proteins prevents the entry into S phase. To investigate the molecular mechanisms of centrosome-dependent cell cycle progress, we performed RNA silencing experiments of two centrosome-associated proteins, pericentriolar material 1 (PCM-1) and pericentrin, in primary human fibroblasts. We found that cells depleted of PCM-1 or pericentrin show lower levels of markers for S phase and cell proliferation, including cyclin A, Ki-67, proliferating cell nuclear antigen, minichromosome maintenance deficient 3, and phosphorylated retinoblastoma protein. Also, the percentage of cells undergoing DNA replication was reduced by >50%. At the same time, levels of p53 and p21 increased in these cells, and cells were predisposed to undergo senescence. Conversely, depletion of centrosome proteins in cells lacking p53 did not cause any cell cycle arrest. Inhibition of p38 mitogen-activated protein kinase rescued cell cycle activity after centrosome protein depletion, indicating that p53 is activated by the p38 stress pathway.
Srsen
Vlastimil
V
Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, Scotland, UK.
Gnadt
Nicole
N
Dammermann
Alexander
A
Merdes
Andreas
A
D000818:Animals; D000906:Antibodies; D000941:Antigens / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D001324:Autoantigens / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018385:Centrosome / Q000378:metabolism*; D019925:Cyclin A / Q000378:metabolism; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D004261:DNA Replication; D005347:Fibroblasts; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering; D016160:Retinoblastoma Protein / Q000378:metabolism; D016196:S Phase; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D000906:Antibodies; D000941:Antigens; D001324:Autoantigens; D018797:Cell Cycle Proteins; D019925:Cyclin A; D050759:Cyclin-Dependent Kinase Inhibitor p21; D019394:Ki-67 Antigen; C086074:PCM1 protein, human; D018809:Proliferating Cell Nuclear Antigen; D034741:RNA, Small Interfering; D016160:Retinoblastoma Protein; D016159:Tumor Suppressor Protein p53; C086178:pericentrin; D048051:p38 Mitogen-Activated Protein Kinases