401
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Abstract
NPM1 is a crucial gene to consider in the context of the genetics and biology of cancer. NPM1 is frequently overexpressed, mutated, rearranged and deleted in human cancer. Traditionally regarded as a tumour marker and a putative proto-oncogene, it has now also been attributed with tumour-suppressor functions. Therefore, NPM can contribute to oncogenesis through many mechanisms. The aim of this review is to analyse the role of NPM in cancer, and examine how deregulated NPM activity (either gain or loss of function) can contribute to tumorigenesis.
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Affiliation(s)
- Silvia Grisendi
- Cancer Biology & Genetics Program, Department of Pathology, Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA
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402
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Caudill JSC, Sternberg AJ, Li CY, Tefferi A, Lasho TL, Steensma DP. C-terminal nucleophosmin mutations are uncommon in chronic myeloid disorders. Br J Haematol 2006; 133:638-41. [PMID: 16704439 DOI: 10.1111/j.1365-2141.2006.06081.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
C-terminal somatic mutations in nucleophosmin (NPM), a nucleolar shuttling protein that binds p53 and p19(Arf), were recently described in karyotypically normal acute myeloid leukaemia (AML). We analysed primary marrow samples from 150 patients with various chronic myeloid disorders for mutations in the NPM1 gene encoding NPM. NPM1 mutations (tetranucleotide duplication) were detected in three patients, all of whom had chronic myelomonocytic leukaemia (CMML) and a short (<1 year) survival, with rapid progression to overt AML. All other patients were NPM1-wild type in the region analysed. In conclusion, C-terminal NPM mutations are uncommon in chronic myeloid neoplasia, but if present may represent an evolving leukaemic clone.
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Affiliation(s)
- Jonathan S C Caudill
- Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
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403
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404
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Grimm T, Hölzel M, Rohrmoser M, Harasim T, Malamoussi A, Gruber-Eber A, Kremmer E, Eick D. Dominant-negative Pes1 mutants inhibit ribosomal RNA processing and cell proliferation via incorporation into the PeBoW-complex. Nucleic Acids Res 2006; 34:3030-43. [PMID: 16738141 PMCID: PMC1474060 DOI: 10.1093/nar/gkl378] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The nucleolar PeBoW-complex, consisting of Pes1, Bop1 and WDR12, is essential for cell proliferation and processing of ribosomal RNA in mammalian cells. Here we have analysed the physical and functional interactions of Pes1 deletion mutants with the PeBoW-complex. Pes1 mutants M1 and M5, with N- and C-terminal truncations, respectively, displayed a dominant-negative phenotype. Both mutants showed nucleolar localization, blocked processing of the 36S/32S precursors to mature 28S rRNA, inhibited cell proliferation, and induced high p53 levels in proliferating, but not in resting cells. Mutant M1 and M5 proteins associated with large pre-ribosomal complexes and co-immunoprecipitated Bop1 and WDR12 proteins indicating their proper incorporation into the PeBoW-complex. We conclude that the dominant-negative effect of the M1 and M5 mutants is mediated by the impaired function of the PeBoW-complex.
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Affiliation(s)
- Thomas Grimm
- Institute of Clinical Molecular Biology and Tumour Genetics, GSF Research Centre for Environment and Health, Marchioninistrasse 25, 81377 Munich, Germany
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405
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Thiede C, Koch S, Creutzig E, Steudel C, Illmer T, Schaich M, Ehninger G. Prevalence and prognostic impact of NPM1 mutations in 1485 adult patients with acute myeloid leukemia (AML). Blood 2006; 107:4011-20. [PMID: 16455956 DOI: 10.1182/blood-2005-08-3167] [Citation(s) in RCA: 524] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Mutations of the nucleophosmin (NPM1) gene have recently been described in patients with acute myeloid leukemia (AML). To clarify the prevalence as well as the clinical impact of this mutation, we investigated 1485 patients with AML for NPM1 exon 12 mutations using fragment analysis. A 4 bp insert was detected in 408 of 1485 patients (27.5%). Sequence analysis revealed known mutations (type A, B, and D) as well as 13 novel alterations in 229 analyzed cases. NPM1 mutations were most prevalent in patients with normal karyotype (NK) (324 of 709; 45.7%) compared with 58 of 686 with karyotype abnormalities (8.5%; P < .001) and were significantly associated with several clinical parameters (high bone marrow [BM] blasts, high white blood cell [WBC] and platelet counts, female sex). NPM1 alterations were associated with FLT3-ITD mutations, even if restricted to patients with NK (NPM1-mut/FLT3-ITD: 43.8%; versus NPM1-wt/FLT3-ITD: 19.9%; P < .001). The analysis of the clinical impact in 4 groups (NPM1 and FLT3-ITD single mutants, double mutants, and wild-type [wt] for both) revealed that patients having only an NPM1 mutation had a significantly better overall and disease-free survival and a lower cumulative incidence of relapse. In conclusion, NPM1 mutations represent a common genetic abnormality in adult AML. If not associated with FLT3-ITD mutations, mutant NPM1 appears to identify patients with improved response toward treatment.
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Affiliation(s)
- Christian Thiede
- Medizinische Klinik und Poliklinik I, Universitätsklinikum Carl Gustav Carus der Technischen Universität, Fetscherstrasse 74, 01307 Dresden, Germany.
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406
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Enomoto T, Lindström MS, Jin A, Ke H, Zhang Y. Essential role of the B23/NPM core domain in regulating ARF binding and B23 stability. J Biol Chem 2006; 281:18463-72. [PMID: 16679321 DOI: 10.1074/jbc.m602788200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
How cells coordinate inhibition of growth and division during genotoxic events is fundamental to our understanding of the origin of cancer. Despite increasing interest and extensive study, the mechanisms that link regulation of DNA synthesis and ribosomal biogenesis remain elusive. Recently, the tumor suppressor p14(ARF) (ARF) has been shown to interact functionally with the nucleolar protein B23/NPM (B23) and inhibit rRNA biogenesis. However, the molecular basis of the ARF-B23 interaction is hitherto unclear. Here we show that a highly conserved motif in the B23 oligomerization domain is essential for mediating ARF binding in vivo. Mutagenesis of conserved B23 core residues (L102A, G105A, G107A) prevented B23 from interacting with ARF. Modeling of the B23 core indicated that substitutions in the GSGP loop motif could trigger conformational changes in B23 thereby obstructing ARF binding. Interestingly, the GSGP loop mutants were unstable, defective for oligomerization, and delocalized from the nucleolus to the nucleoplasm. B23 core mutants displayed increased ubiquitination and proteasomal degradation. We conclude that the functional integrity of the B23 core motif is required for stability, efficient nucleolar localization as well as ARF binding.
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Affiliation(s)
- Takeharu Enomoto
- Department of Radiation Oncology, University of North Carolina at Chapel Hill, NC 27599-7512, USA
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407
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Zhang Y, Zhang M, Yang L, Xiao Z. NPM1 mutations in myelodysplastic syndromes and acute myeloid leukemia with normal karyotype. Leuk Res 2006; 31:109-11. [PMID: 16678898 DOI: 10.1016/j.leukres.2006.03.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2006] [Revised: 03/06/2006] [Accepted: 03/15/2006] [Indexed: 12/01/2022]
Abstract
Mutations at exon 12 of the nucleophosmin (NPM1) gene are the most frequent acquired molecular abnormalities in adult and pediatric acute myeloid leukaemia (AML) with normal karyotype. We screened 28 patients with new diagnosed primary AML with normal karyotype, 38 patients with myelodysplastic symdromes (MDS) and 19 healthy volunteer for mutations at exon 12 of NPM1 gene. NPM1 mutations were identified in four AML patients and two MDS patients, including one novel sequence variant. As far as we know, this is the first report of NPM1 mutation in patients with MDS in the English literature until now, and our primary data support that NPM1 mutations may be also involved in the pathogenesis of MDS.
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Affiliation(s)
- Yue Zhang
- State Key Laboratory of Experiment Hematology, Institute of Hematology and Blood Disease Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 288 Nanjing Road, Tianjin 300020, PR China
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408
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Rego EM, Ruggero D, Tribioli C, Cattoretti G, Kogan S, Redner RL, Pandolfi PP. Leukemia with distinct phenotypes in transgenic mice expressing PML/RAR alpha, PLZF/RAR alpha or NPM/RAR alpha. Oncogene 2006; 25:1974-9. [PMID: 16331271 DOI: 10.1038/sj.onc.1209216] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recurrent chromosomal translocations involving the RAR alpha locus on chromosome 17 are the hallmark of acute promyelocytic leukemia (APL). The RAR alpha gene fuses to variable partners (PML, PLZF, NPM, NuMA and STAT5B: X genes) leading to the expression of APL-specific fusion proteins with identical RAR alpha moieties. To analyse whether the variable X moiety could affect the activity of the fusion protein in vivo, we generated and characterized, on a comparative basis, NPM/RAR alpha transgenic mice (TM) in which the fusion gene is expressed under the control of a human Cathepsin G (hCG) minigene. We compared the features of the leukemia observed in these TM with those in hCG-PML/RAR alpha and hCG-PLZF/RAR alpha TM. In all three transgenic models, leukemia developed after a variably long latency, with variable penetrance. However, the three leukemias displayed distinct cytomorphological features. hCG-NPM/RAR alpha leukemic cells resembled monoblasts. This phenotype contrasts with what was observed in the hCG-PML/RAR alpha TM model in which the leukemic phase was characterized by the proliferation of promyelocytic blasts. Similarly, hCG-PLZF/RAR alpha TM displayed a different phenotype where terminally differentiated myeloid cells predominated. Importantly, the NPM/RAR alpha oncoprotein was found to localize in the nucleolus, unlike PML/RAR alpha and PLZF/RAR alpha, thus possibly interfering with the normal function of NPM. Similarly to what was observed in human APL patients, we found that NPM/RAR alpha and PML/RAR alpha, but not PLZF/RAR alpha leukemia, was responsive to all-trans retinoic acid (ATRA) or As2O3 treatments. Taken together, our results underscore the critical relevance of the X moiety in dictating the biology of the disease and the activity of the APL fusion oncoprotein.
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Affiliation(s)
- E M Rego
- Cancer Biology and Genetics Program, Department of Pathology, Memorial Sloan-Kettering Cancer Center, Sloan Kettering Institute, New York, NY 10021, USA
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409
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Yu Y, Maggi LB, Brady SN, Apicelli AJ, Dai MS, Lu H, Weber JD. Nucleophosmin is essential for ribosomal protein L5 nuclear export. Mol Cell Biol 2006; 26:3798-809. [PMID: 16648475 PMCID: PMC1488996 DOI: 10.1128/mcb.26.10.3798-3809.2006] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2005] [Revised: 12/07/2005] [Accepted: 02/24/2006] [Indexed: 12/20/2022] Open
Abstract
Nucleophosmin (NPM/B23) is a key regulator in the regulation of a number of processes including centrosome duplication, maintenance of genomic integrity, and ribosome biogenesis. While the mechanisms underlying NPM function are largely uncharacterized, NPM loss results in severe dysregulation of developmental and growth-related events. We show that NPM utilizes a conserved CRM1-dependent nuclear export sequence in its amino terminus to enable its shuttling between the nucleolus/nucleus and cytoplasm. In search of NPM trafficking targets, we biochemically purified NPM-bound protein complexes from HeLa cell lysates. Consistent with NPM's proposed role in ribosome biogenesis, we isolated ribosomal protein L5 (rpL5), a known chaperone for the 5S rRNA. Direct interaction of NPM with rpL5 mediated the colocalization of NPM with maturing nuclear 60S ribosomal subunits, as well as newly exported and assembled 80S ribosomes and polysomes. Inhibition of NPM shuttling or loss of NPM blocked the nuclear export of rpL5 and 5S rRNA, resulting in cell cycle arrest and demonstrating that NPM and its nuclear export provide a unique and necessary chaperoning activity to rpL5/5S.
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MESH Headings
- Active Transport, Cell Nucleus
- Amino Acid Sequence
- Animals
- Blotting, Western
- Cell Nucleus/metabolism
- Chromatography, Liquid
- Consensus Sequence
- Conserved Sequence
- Electrophoresis, Polyacrylamide Gel
- Evolution, Molecular
- Fluorescent Dyes
- Green Fluorescent Proteins/metabolism
- HeLa Cells
- Humans
- In Situ Hybridization, Fluorescence
- Indoles
- Karyopherins/metabolism
- Mice
- Molecular Sequence Data
- NIH 3T3 Cells
- Nuclear Proteins/chemistry
- Nuclear Proteins/metabolism
- Nuclear Proteins/physiology
- Nucleophosmin
- Precipitin Tests
- Proteome/analysis
- Proteomics
- RNA Interference
- Receptors, Cytoplasmic and Nuclear/metabolism
- Rhodamines
- Ribosomal Proteins/metabolism
- Sequence Homology, Amino Acid
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Subcellular Fractions/chemistry
- Exportin 1 Protein
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Affiliation(s)
- Yue Yu
- Department of Internal Medicine, Division of Molecular Oncology, Siteman Cancer Center, Washington University School of Medicine, Campus Box 8069, 660 South Euclid Avenue, St. Louis, Missouri 63110, USA
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410
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Abstract
It has been over a decade since mutations in BRCA1 and BRCA2 were found to be associated with a small number of familial breast cancer cases. BRCA1 is a large protein that interacts with many other proteins that have diverse functions, so it has been a challenge to determine how defects in its function could lead to cancer. One particular protein, BARD1, seems to be an important regulator of the tumour-suppressor function of BRCA1, as well as acting as a tumour suppressor itself. BARD1 is indispensable for cell viability, so loss-of-function mutations are rare, but mutations and truncations that alter its function might be involved in the pathogenesis of breast cancer.
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Affiliation(s)
- Irmgard Irminger-Finger
- Biology of Aging Laboratory, Department of Geriatrics, Geneva University and University Hospitals, 30, Bloulevard de la Cluse, CH-1211 Geneva, Switzerland.
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411
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Frehlick LJ, Eirín-López JM, Jeffery ED, Hunt DF, Ausió J. The characterization of amphibian nucleoplasmins yields new insight into their role in sperm chromatin remodeling. BMC Genomics 2006; 7:99. [PMID: 16646973 PMCID: PMC1479337 DOI: 10.1186/1471-2164-7-99] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Accepted: 04/28/2006] [Indexed: 12/04/2022] Open
Abstract
Background Nucleoplasmin is a nuclear chaperone protein that has been shown to participate in the remodeling of sperm chromatin immediately after fertilization by displacing highly specialized sperm nuclear basic proteins (SNBPs), such as protamine (P type) and protamine-like (PL type) proteins, from the sperm chromatin and by the transfer of histone H2A-H2B. The presence of SNBPs of the histone type (H type) in some organisms (very similar to the histones found in somatic tissues) raises uncertainty about the need for a nucleoplasmin-mediated removal process in such cases and poses a very interesting question regarding the appearance and further differentiation of the sperm chromatin remodeling function of nucleoplasmin and the implicit relationship with SNBP diversity The amphibians represent an unique opportunity to address this issue as they contain genera with SNBPs representative of each of the three main types: Rana (H type); Xenopus (PL type) and Bufo (P type). Results In this work, the presence of nucleoplasmin in oocyte extracts from these three organisms has been assessed using Western Blotting. We have used mass spectrometry and cloning techniques to characterize the full-length cDNA sequences of Rana catesbeiana and Bufo marinus nucleoplasmin. Northern dot blot analysis shows that nucleoplasmin is mainly transcribed in the egg of the former species. Phylogenetic analysis of nucleoplasmin family members from various metazoans suggests that amphibian nucleoplasmins group closely with mammalian NPM2 proteins. Conclusion We have shown that these organisms, in striking contrast to their SNBPs, all contain nucleoplasmins with very similar primary structures. This result has important implications as it suggests that nucleoplasmin's role in chromatin assembly during early zygote development could have been complemented by the acquisition of a new function of non-specifically removing SNBPs in sperm chromatin remodeling. This acquired function would have been strongly determined by the constraints imposed by the appearance and differentiation of SNBPs in the sperm.
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Affiliation(s)
- Lindsay J Frehlick
- Department of Biochemistry and Microbiology, University of Victoria, Petch Building, Victoria, BC, V8W 3P6, Canada
| | - José María Eirín-López
- Department of Biochemistry and Microbiology, University of Victoria, Petch Building, Victoria, BC, V8W 3P6, Canada
- Departamento de Biología Celular y Molecular, Universidade da Coruña, Campus de A Zapateira s/n, E-15071, Spain
| | - Erin D Jeffery
- Department of Chemistry and Pathology, University of Virginia, Charlottesville, VA 22901, USA
| | - Donald F Hunt
- Department of Chemistry and Pathology, University of Virginia, Charlottesville, VA 22901, USA
| | - Juan Ausió
- Department of Biochemistry and Microbiology, University of Victoria, Petch Building, Victoria, BC, V8W 3P6, Canada
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412
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Cathelin S, Rébé C, Haddaoui L, Simioni N, Verdier F, Fontenay M, Launay S, Mayeux P, Solary E. Identification of proteins cleaved downstream of caspase activation in monocytes undergoing macrophage differentiation. J Biol Chem 2006; 281:17779-88. [PMID: 16636047 DOI: 10.1074/jbc.m600537200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
We have shown previously that caspases were specifically involved in the differentiation of peripheral blood monocytes into macrophages while not required for monocyte differentiation into dendritic cells. To identify caspase targets in monocytes undergoing macrophagic differentiation, we used the human monocytic leukemic cell line U937, whose macrophagic differentiation induced by exposure to 12-O-tetradecanoylphorbol 13-acetate (TPA) can be prevented by expression of the baculovirus caspase-inhibitory protein p35. A comparative two-dimensional gel proteomic analysis of empty vector- and p35-transfected cells after 12 h of exposure to 20 nm TPA, followed by mass spectrometry analysis, identified 38 differentially expressed proteins. Those overexpressed in p35-expressing cells (n = 16) were all full-length, whereas half of those overexpressed in control cells (n = 22) were N- or C-terminal cleavage fragments. The cleavage or degradation of seven of these proteins was confirmed in peripheral blood monocytes undergoing macrophage colony-stimulating factor-induced macrophagic differentiation. In U937 cells exposed to TPA, these proteolytic events can be inhibited by expression of a caspase-8 dominant negative mutant or the cowpox virus CrmA caspase inhibitor. These cleavages provide new insights to analyze the role of caspases in this specific differentiation program.
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Affiliation(s)
- Séverine Cathelin
- INSERM UMR 517, IFR 100, Faculty of Medicine, 7 Boulevard Jeanne d'Arc, F-21079 Dijon Cedex, France
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413
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Li J, Sejas DP, Rani R, Koretsky T, Bagby GC, Pang Q. Nucleophosmin regulates cell cycle progression and stress response in hematopoietic stem/progenitor cells. J Biol Chem 2006; 281:16536-45. [PMID: 16608843 DOI: 10.1074/jbc.m601386200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Nucleophosmin (NPM) is a multifunctional protein frequently overexpressed in actively proliferating cells. Strong evidence indicates that NPM is required for embryonic development and genomic stability. Here we report that NPM enhances the proliferative potential of hematopoietic stem cells (HSCs) and increases their survival upon stress challenge. Both short term liquid culture and clonogenic progenitor cell assays show a selective expansion of NPM-overexpressing HSCs. Interestingly, HSCs infected with NPM retrovirus show significantly reduced commitment to myeloid differentiation compared with vector-transduced cells, and majority of the NPM-overexpressing cells remains primitive during a 5-day culture. Bone marrow transplantation experiments demonstrate that NPM promotes the self-renewal of long term repopulating HSCs while attenuated their commitment to myeloid differentiation. NPM overexpression induces rapid entry of HSCs into the cell cycle and suppresses the expression of several negative cell cycle regulators that are associated with G(1)-to-S transition. NPM knockdown elevates expression of these negative regulators and exacerbates stress-induced cell cycle arrest. Finally, overexpression of NPM promotes the survival and recovery of HSCs and progenitors after exposure to DNA damage, oxidative stress, and hematopoietic injury both in vivo and in vitro. DNA repair kinetics study suggests that NPM has a role in reducing the susceptibility of chromosomal DNA to damage rather than promoting DNA damage repair. Together, these results indicate that NPM plays an important role in hematopoiesis via mechanisms involving modulation of HSC/progenitor cell cycle progression and stress response.
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Affiliation(s)
- June Li
- Division of Experimental Hematology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
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414
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Palaniswamy V, Moraes KCM, Wilusz CJ, Wilusz J. Nucleophosmin is selectively deposited on mRNA during polyadenylation. Nat Struct Mol Biol 2006; 13:429-35. [PMID: 16604083 PMCID: PMC2811576 DOI: 10.1038/nsmb1080] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Accepted: 03/06/2006] [Indexed: 12/19/2022]
Abstract
Nucleophosmin (NPM), an abundant, predominantly nucleolar protein that influences numerous cellular processes, was shown to specifically associate with the bodies of messenger RNAs as a result of the process of 3'-end formation. NPM deposition requires polyadenylation but not the 3' cleavage event to occur on the transcript. Furthermore, the protein does not associate with RNAs bearing a preformed poly(A) tail or with mRNAs that have undergone cleavage but not polyadenylation. A region within 10 bases upstream of the AAUAAA element is required for NPM association, but deposition of the protein seems to be sequence independent. NPM association with poly(A)(+) mRNAs was also demonstrated in vivo. NPM, therefore, represents a mark left on transcripts as a result of 3'-end processing and may have a role in one or more of a variety of post-transcriptional processes influenced by the polyadenylation event.
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Affiliation(s)
- Viswanathan Palaniswamy
- Department of Microbiology, Immunology & Pathology, Colorado State University, 1619 Campus Delivery, Fort Collins, Colorado 80523, USA
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415
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Falini B, Bigerna B, Pucciarini A, Tiacci E, Mecucci C, Morris SW, Bolli N, Rosati R, Hanissian S, Ma Z, Sun Y, Colombo E, Arber DA, Pacini R, La Starza R, Verducci Galletti B, Galletti BV, Liso A, Martelli MP, Diverio D, Pelicci PG, Lo Coco F, Coco FL, Martelli MF. Aberrant subcellular expression of nucleophosmin and NPM-MLF1 fusion protein in acute myeloid leukaemia carrying t(3;5): a comparison with NPMc+ AML. Leukemia 2006; 20:368-71. [PMID: 16341033 DOI: 10.1038/sj.leu.2404068] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
MESH Headings
- Acute Disease
- Cell Nucleus/metabolism
- Chromosomes, Human, Pair 3/genetics
- Chromosomes, Human, Pair 5/genetics
- Cytoplasm/metabolism
- Gene Expression Regulation, Leukemic
- Humans
- Leukemia, Myeloid/drug therapy
- Leukemia, Myeloid/genetics
- Nuclear Proteins/biosynthesis
- Nuclear Proteins/genetics
- Nucleophosmin
- Oncogene Proteins, Fusion/analysis
- Oncogene Proteins, Fusion/biosynthesis
- Oncogene Proteins, Fusion/genetics
- Subcellular Fractions/chemistry
- Translocation, Genetic/genetics
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416
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Chou WC, Tang JL, Lin LI, Yao M, Tsay W, Chen CY, Wu SJ, Huang CF, Chiou RJ, Tseng MH, Lin DT, Lin KH, Chen YC, Tien HF. Nucleophosmin Mutations in De novo Acute Myeloid Leukemia: The Age-Dependent Incidences and the Stability during Disease Evolution. Cancer Res 2006; 66:3310-6. [PMID: 16540685 DOI: 10.1158/0008-5472.can-05-4316] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Nucleophosmin (NPM) mutations have been found in a significant proportion of adults with de novo acute myeloid leukemia (AML), especially in those of a normal karyotype. These results provide a basis for studies of the pathogenesis in this specific subgroup of AML. In this study, NPM mutations were analyzed in 173 Chinese patients of de novo AML, including adults and children. We found that NPM mutations were present in 19.1% of the overall population and 40.3% of those with a normal karyotype. Adults had a significantly higher incidence of NPM mutations than children [32 of 126 (25.4%) versus 1 of 47 (2.1%), P < 0.001]. NPM mutations were closely associated with normal karyotype (P < 0.001) and internal tandem duplication of FLT3 (P = 0.002), but negatively associated with CEBPA mutations (P = 0.032) and expression of CD34 (P < 0.001) and HLA-DR (P = 0.003). Serial analyses of NPM mutations showed the mutation disappeared at complete remission, but the same mutation reappeared at relapse, except for one who lost the mutation at the second relapse, when new cytogenetic abnormalities emerged. None acquired novel mutations during the follow-up period. In conclusion, NPM mutations occur in an age-dependent fashion. Moreover, the findings that NPM mutations are stable during disease evolution and closely associated with disease status make it a potential marker for monitoring minimal residual disease.
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Affiliation(s)
- Wen-Chien Chou
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
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417
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Niimi H, Harada H, Harada Y, Ding Y, Imagawa J, Inaba T, Kyo T, Kimura A. Hyperactivation of the RAS signaling pathway in myelodysplastic syndrome with AML1/RUNX1 point mutations. Leukemia 2006; 20:635-44. [PMID: 16467864 DOI: 10.1038/sj.leu.2404136] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
AML1/RUNX1 mutations have been reported frequently in myelodysplastic syndrome (MDS) patients, especially those diagnosed with refractory anemia with excess blast (RAEB), RAEB in transformation (RAEBt), or AML following MDS (these categories are defined as MDS/AML). Although AML1 mutations are suspected to play a pivotal role in the development of MDS/AML, acquisition of additional genetic alterations is also necessary. We analyzed gene alterations in MDS/AML patients with AML1 mutations, comparing them to alterations in those without an AML1 mutation. AML1 mutations were significantly associated with -7/7q-, whereas MDS/AML patients without AML1 mutations showed a high frequency of -5/5q- and a complex karyotype. Patients with AML1 mutations showed more mutations of their FLT3, N-RAS, PTPN11, and NF1 genes, resulting in a significantly higher mutation frequency for receptor tyrosine kinase (RTK)-RAS signaling pathways in AML1-mutated MDS/AML patients compared to AML1-wild-type MDS/AML patients (38% versus 6.3%, P < 0.0001). Conversely, p53 mutations were detected only in patients without AML1 mutations. Furthermore, blast cells of the AML1-mutated patients expressing surface c-KIT, and SHP-2 mutants contributed to prolonged and enhanced extracellular signal-regulated kinase activation following stem cell factor stimulation. Our results suggest that MDS/AML arising from AML1/RUNX1 mutations has a significant association with -7/7q- alteration, and frequently involves RTK-RAS signaling pathway activation.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Antineoplastic Combined Chemotherapy Protocols/therapeutic use
- Cell Line, Tumor
- Chromosome Aberrations
- Core Binding Factor Alpha 2 Subunit/genetics
- Cytogenetic Analysis
- DNA Mutational Analysis/methods
- Epidermal Growth Factor/pharmacology
- Extracellular Signal-Regulated MAP Kinases/drug effects
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Female
- Genes, ras
- Granulocyte-Macrophage Colony-Stimulating Factor/pharmacology
- Humans
- Intracellular Signaling Peptides and Proteins/genetics
- Leukemia, Myeloid, Acute/drug therapy
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/metabolism
- Ligands
- Male
- Middle Aged
- Myelodysplastic Syndromes/genetics
- Myelodysplastic Syndromes/metabolism
- Point Mutation
- Protein Tyrosine Phosphatase, Non-Receptor Type 11
- Protein Tyrosine Phosphatases/genetics
- Sensitivity and Specificity
- Signal Transduction
- Tumor Cells, Cultured
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Affiliation(s)
- H Niimi
- Department of Hematology/Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan
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418
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Kwok C, Zeisig BB, Dong S, So CWE. Forced homo-oligomerization of RARalpha leads to transformation of primary hematopoietic cells. Cancer Cell 2006; 9:95-108. [PMID: 16473277 DOI: 10.1016/j.ccr.2006.01.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Revised: 12/19/2005] [Accepted: 01/10/2006] [Indexed: 11/18/2022]
Abstract
Almost 100% of APL patients carry chimeric transcripts encoding truncated RARalpha fused to homo-oligomerization domains from partner proteins. To gain further insights into the cellular transformation mechanisms mediated by RARalpha fusion proteins, thorough structure/function analyses have been performed and identified the POZ homo-oligomerization domain as the minimal transformation domain that is necessary and sufficient for PLZF-RARalpha-mediated in vitro transformation of primary hematopoietic cells. A transformation-incompetent PLZF-RARalpha mutant defective in homo-oligomerization but not corepressor interaction could be rescued by synthetic FKBP-oligomerization domains. Furthermore, an artificial FKBP-RARalpha construct not only mimicked various biochemical properties of bona fide RARalpha fusion proteins but also mediated an ATRA-dependent transformation. Taken together, these findings endorse an oligomerization-dependent mechanism for RARalpha-mediated transformation and suggest a potential avenue for molecular therapy.
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Affiliation(s)
- Colin Kwok
- Haemato-Oncology Section, The Institute of Cancer Research, 237 Fulham Road, South Kensington, London SW3 6JB, United Kingdom
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419
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Ma XH, Hu SJ, Ni H, Zhao YC, Tian Z, Liu JL, Ren G, Liang XH, Yu H, Wan P, Yang ZM. Serial analysis of gene expression in mouse uterus at the implantation site. J Biol Chem 2006; 281:9351-60. [PMID: 16434403 DOI: 10.1074/jbc.m511512200] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Although oligonucleotide chips, cDNA microarrays, differential display reverse transcription-PCR, and other approaches have been used to screen implantation-related molecules, the mechanism by which embryo implantation occurs is still unknown. The aim of this study was to profile the differential gene expression between interimplantation site and implantation site in mouse uterus on day 5 of pregnancy by serial analysis of gene expression (SAGE). In our two SAGE libraries of 11-bp tags, the total numbers of tags sequenced were 48,121 for the interimplantation site and 50,227 for the implantation site. There were 1,039 tags specifically expressed at interimplantation site, and 1,252 tags specifically expressed at the implantation site. Based on the p value, there were 195 tags significantly up-regulated at the interimplantation site and 261 tags significantly up-regulated at the implantation site, of which 100 genes were single matched at the interimplantation site and 127 genes were single matched at the implantation site, respectively. By reverse transcription-PCR, the tag ratio between the implantation site and interimplantation site was verified on 14 significantly changed genes. Using in situ hybridization, 1810014L12Rik, Psmb5, Cd63, Npm1, Fads3, and Tagln2 were shown to be highly expressed at the implantation site compared with the interimplantation site. Compared with the interimplantation site, Ddx39 was strongly expressed in the subluminal stromal cells at the implantation site on day 5 of pregnancy. Ddx39 expression at the implantation site was specifically induced by active blastocysts. Additionally, Ddx39 expression was significantly up-regulated by estrogen in the ovariectomized mice. In our SAGE data, many implantation-related genes were identified in mouse uterus. Our data could be a valuable source for future study on embryo implantation.
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Affiliation(s)
- Xing-Hong Ma
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
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420
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Gonda K, Wudel J, Nelson D, Katoku-Kikyo N, Reed P, Tamada H, Kikyo N. Requirement of the protein B23 for nucleolar disassembly induced by the FRGY2a family proteins. J Biol Chem 2006; 281:8153-60. [PMID: 16415342 PMCID: PMC2222668 DOI: 10.1074/jbc.m512890200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In Xenopus somatic cell nuclear cloning, the nucleoli of donor nuclei rapidly and almost completely disappear in egg cytoplasm. We previously showed that the germ cell-specific proteins FRGY2a and FRGY2b were responsible for this unusually drastic nucleolar disassembly. The nucleolar disassembly occurs without inhibition of pre-rRNA transcription, a well known trigger for nucleolar segregation, and the mechanism for the nucleolar disassembly by FRGY2a and FRGY2b remains largely unknown. In this study, we searched for FRGY2a-interacting proteins and investigated the functional consequences of their interactions through a series of experiments. We showed that during the nucleolar disassembly, FRGY2a localized to the nucleoli of isolated nuclei and was capable of disassembling purified nucleoli, suggesting a direct interaction between FRGY2a and nucleolar components. Using a His tag pulldown approach, we identified the abundant and multifunctional nucleolar protein B23 as a potential target of FRGY2a and its related human protein YB1. A specific interaction between FRGY2a/YB1 and B23 was confirmed by co-immunoprecipitation. Finally, B23 knockdown using short interfering RNA and a subsequent add-back experiment confirmed that B23 was necessary for nucleolar disassembly by YB1. We propose that FRGY2a and YB1 disassemble nucleoli by sequestering B23, which is associated with pre-ribosomes and other structurally important nucleolar components.
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Affiliation(s)
| | | | | | | | | | | | - Nobuaki Kikyo
- To whom correspondence should be addressed: Stem Cell Institute, Division of Hematology, Oncology and Transplantation, Dept. of Medicine, University of Minnesota, MMC 716, 420 Delaware St. SE, Minneapolis, MN 55455. Tel.: 612-624-0498; Fax: 612-624-2436; E-mail:
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421
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Berger R, Busson M, Baranger L, Hélias C, Lessard M, Dastugue N, Speleman F. Loss of the NPM1 gene in myeloid disorders with chromosome 5 rearrangements. Leukemia 2005; 20:319-21. [PMID: 16341035 DOI: 10.1038/sj.leu.2404063] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The assignment with chromosome banding techniques of the breakpoints of the recurrent translocation t(3;5) which leads to NPM1/MLF1 gene fusion in myeloid malignancies has not been unequivocal. In order to assess whether this is due to uncertainty in interpretation of the observed banding pattern or whether it reflects true genomic heterogeneity, we decided to analyze the breakpoint positions using fluorescence in situ (FISH) techniques in eight patients with myeloid malignancies and rearrangements of chromosomes 3 and 5. In three patients, colocalization of the NPM1 and MLF1 spanning BACs was demonstrated and NPM1/MLF1 fusion shown by PCR in one while in the remaining cases breakpoints were located outside the NPM1 and MLF1 loci. Interestingly, loss of a copy of the NPM1 gene was found in three of these latter patients. This findings suggest that haploinsufficiency of NPM1 may play a role in subtypes of myelodysplasias and leukemias.
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Affiliation(s)
- R Berger
- 1EMI 0210 Hôpital Necker-Enfants Malades, Paris, France.
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422
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Shinmura K, Tarapore P, Tokuyama Y, George KR, Fukasawa K. Characterization of centrosomal association of nucleophosmin/B23 linked to Crm1 activity. FEBS Lett 2005; 579:6621-34. [PMID: 16297385 DOI: 10.1016/j.febslet.2005.10.057] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2005] [Revised: 10/20/2005] [Accepted: 10/28/2005] [Indexed: 11/24/2022]
Abstract
Nucleophosmin (NPM)/B23 is a multifunctional protein, involving in a wide variety of basic cellular processes, including ribosome assembly, DNA duplication, nucleocytoplasmic trafficking, and centrosome duplication. It has previously been shown that NPM/B23 localizes to centrosomes, and dissociate from centrosomes upon phosphorylation by Cdk2/cyclin E. However, detail characterization of centrosomal association of NPM/B23 has been hampered by the lack of appropriate antibodies that efficiently detects centrosomally localized NPM/B23, as well as by apparent loss of natural behavior of NPM/B23 when tagged with fluorescent proteins. Here, by the use of newly generated anti-NPM/B23 antibody, we conducted a careful analysis of centrosomal localization of NPM/B23. We found that NPM/B23 localizes between the paired centrioles of unduplicated centrosomes, suggesting the role of NPM/B23 in the centriole pairing. Upon initiation of centrosome duplication, some NPM/B23 proteins remain at mother centrioles of the parental centriole pairs. We further found that inhibition of Crm1 nuclear export receptor results in both accumulation of cyclin E at centrosomes and efficient dissociation of NPM/B23 from centrosomes.
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Affiliation(s)
- Kazuya Shinmura
- Department of Cell Biology, University of Cincinnati College of Medicine, P.O. Box 670521 (3125 Eden Avenue), Cincinnati, OH 45267-0521, United States
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423
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Bettencourt-Dias M, Rodrigues-Martins A, Carpenter L, Riparbelli M, Lehmann L, Gatt MK, Carmo N, Balloux F, Callaini G, Glover DM. SAK/PLK4 is required for centriole duplication and flagella development. Curr Biol 2005; 15:2199-207. [PMID: 16326102 DOI: 10.1016/j.cub.2005.11.042] [Citation(s) in RCA: 467] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2005] [Revised: 10/27/2005] [Accepted: 11/11/2005] [Indexed: 11/24/2022]
Abstract
BACKGROUND SAK/PLK4 is a distinct member of the polo-like kinase family. SAK-/- mice die during embryogenesis, whereas SAK+/- mice develop liver and lung tumors and SAK+/- MEFs show mitotic abnormalities. However, the mechanism underlying these phenotypes is still not known. RESULTS Here, we show that downregulation of SAK in Drosophila cells, by mutation or RNAi, leads to loss of centrioles, the core structures of centrosomes. Such cells are able to undergo repeated rounds of cell division, but display broad disorganized mitotic spindle poles. We also show that SAK mutants lose their centrioles during the mitotic divisions preceding male meiosis but still produce cysts of 16 primary spermatocytes as in the wild-type. Mathematical modeling of the stereotyped cell divisions of spermatogenesis can account for such loss by defective centriole duplication. The majority of spermatids in SAK mutants lack centrioles and so are unable to make sperm axonemes. Finally, we show that depletion of SAK in human cells also prevents centriole duplication and gives rise to mitotic abnormalities. CONCLUSIONS SAK/PLK4 is necessary for centriole duplication both in Drosophila and human cells. Drosophila cells tolerate the lack of centrioles and undertake mitosis but cannot form basal bodies and hence flagella. Human cells depleted of SAK show error-prone mitosis, likely to underlie its tumor-suppressor role.
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Affiliation(s)
- M Bettencourt-Dias
- Cancer Research UK Cell Cycle Genetics Research Group, Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, United Kingdom.
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424
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Budhu AS, Wang XW. Loading and unloading: orchestrating centrosome duplication and spindle assembly by Ran/Crm1. Cell Cycle 2005; 4:1510-4. [PMID: 16294017 PMCID: PMC1402358 DOI: 10.4161/cc.4.11.2187] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The cell cycle is an intricate process of DNA replication and cell division that concludes with the formation of two genetically equivalent daughter cells. In this progression, the centrosome is duplicated once and only once during the G1/S transition to produce the bipolar spindle and ensure proper chromosome segregation. The presence of multiple centrosomes in cancer cells suggests that this process is mis-regulated during carcinogenesis. This suggests that certain factors exist that license the progression of centrosome duplication and serve to inhibit further duplications during a single cell cycle. Recent studies suggest that the Ran/Crm1 complex not only regulates nucleocytoplasmic transport but is also independently involved in mitotic spindle assembly. Factors that are capable of interacting with Ran/Crm1 through their nuclear export sequences, such as cyclins/cdks, p53 and Brca1/2, may potentially function as centrosome checkpoints akin to the G1/S and G2/M checkpoints of the cell cycle. Our recent findings indicate that nucleophosmin, a protein whose trafficking is mediated by the Ran/Crm1 network, is one of such checkpoint factors for maintaining proper centrosome duplication. We propose that Ran/Crm1 may act as a 'loading dock' to coordinate various checkpoint factors in regulating the fidelity of centrosome duplication during cell cycle progression, and the disruption of these processes may lead to genomic instability and an acceleration of oncogenesis.
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Affiliation(s)
- Anuradha S. Budhu
- Liver Carcinogenesis Section; Laboratory of Human Carcinogenesis; Center for Cancer Research; NCI; NIH; Bethesda, Maryland USA
| | - Xin W. Wang
- Liver Carcinogenesis Section; Laboratory of Human Carcinogenesis; Center for Cancer Research; NCI; NIH; Bethesda, Maryland USA
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