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In Keol Baek, Yeun Kyu Jang, Tae H Lee, JooHun Lee
Mammalian cells are capable of de novo centriole formation after the removal of existing centrioles. This suggests that de novo centriole assembly is repressed in normally duplicating cells to maintain a constant number of centrioles in the cells. However, neither the mechanism of de novo centriole assembly nor that of its hypothesized repression is understood due to the lack of an experimental system. We found that the heat shock (HS; 42°C, 2 h) of mouse embryonic fibroblasts caused the separation of centriole pairs, a transient increase in polo-like kinase (Plk) 4 expression, and the formation of a complex containing γ-tubulin, pericentrin, HS protein (Hsp) 90, and Plk4, in approximately half of the cells...
December 9, 2016: Cytoskeleton
Christian Arquint, Erich A Nigg
Centrioles are microtubule-based core components of centrosomes and cilia. They are duplicated exactly once during S-phase progression. Central to formation of each new (daughter) centriole is the formation of a nine-fold symmetrical cartwheel structure onto which microtubule triplets are deposited. In recent years, a module comprising the protein kinase polo-like kinase 4 (PLK4) and the two proteins STIL and SAS-6 have been shown to stay at the core of centriole duplication. Depletion of any one of these three proteins blocks centriole duplication and, conversely, overexpression causes centriole amplification...
October 15, 2016: Biochemical Society Transactions
I Lohse, J M Mason, P J Cao, Melania Pintilie, M R Bray, D W Hedley
BACKGROUND: Polo-like kinase 4 (PKL4) plays a key role in centriole replication. Hence PLK4 inhibition disrupts mitosis, and offers a novel approach to treating chromosomally unstable cancers, including pancreatic cancer. CFI-400945 is a first in class small molecule PLK4 inhibitor, currently undergoing early phase clinical trials. RESULTS: Treatment with CFI-400945 significantly reduced tumor growth and increased survival in four out of the six models tested. Consistent with PLK4 inhibition, we observed reduced expression of the proliferation marker Ki-67 associated with an increase in nuclear diameter during treatment with CFI-400945...
November 25, 2016: Oncotarget
Karineh Kazazian, Christopher D Go, Hannah Wu, Olga Brashavitskaya, Roland S Z Xu, James W Dennis, Anne-Claude Gingras, Carol Swallow
The polo family serine threonine kinase Plk4 has been proposed as a therapeutic target in advanced cancers based on increased expression in primary human cancers, facilitation of tumor growth in murine xenograft models, and centrosomal amplification induced by its overexpression. However, both the causal link between these phenomena and the feasibility of selective Plk4 inhibition remain unclear. Here we characterize Plk4-dependent cancer cell migration and invasion as well as local invasion and metastasis of cancer xenografts...
November 21, 2016: Cancer Research
Marjorie Fournier, Meritxell Orpinell, Cédric Grauffel, Elisabeth Scheer, Jean-Marie Garnier, Tao Ye, Virginie Chavant, Mathilde Joint, Fumiko Esashi, Annick Dejaegere, Pierre Gönczy, László Tora
Lysine acetylation is a widespread post-translational modification regulating various biological processes. To characterize cellular functions of the human lysine acetyltransferases KAT2A (GCN5) and KAT2B (PCAF), we determined their acetylome by shotgun proteomics. One of the newly identified KAT2A/2B substrate is polo-like kinase 4 (PLK4), a key regulator of centrosome duplication. We demonstrate that KAT2A/2B acetylate the PLK4 kinase domain on residues K45 and K46. Molecular dynamics modelling suggests that K45/K46 acetylation impairs kinase activity by shifting the kinase to an inactive conformation...
October 31, 2016: Nature Communications
Marco Gottardo, Giuliano Callaini, Maria Giovanna Riparbelli
Mutations in Klp10A, a microtubule-depolymerising Kinesin-13, lead to overly long centrioles in Drosophila male germ cells. We demonstrated that the loss of Klp10A modifies the distribution of typical proteins involved in centriole assembly and function. In the absence of Klp10A the distribution of Drosophila pericentrin-like protein (Dplp), Sas-4 and Sak/Plk4 that are restricted in control testes to the proximal end of the centriole increase along the centriole length. Remarkably, the cartwheel is lacking or it appears abnormal in mutant centrioles, suggesting that this structure may spatially delimit protein localization...
December 16, 2016: Cell Cycle
Daniel Ian McSkimming, Shima Dastgheib, Timothy R Baffi, Dominic P Byrne, Samantha Ferries, Steven Thomas Scott, Alexandra C Newton, Claire E Eyers, Krzysztof J Kochut, Patrick A Eyers, Natarajan Kannan
Multiple sequence alignments (MSAs) are a fundamental analysis tool used throughout biology to investigate relationships between protein sequence, structure, function, evolutionary history, and patterns of disease-associated variants. However, their widespread application in systems biology research is currently hindered by the lack of user-friendly tools to simultaneously visualize, manipulate and query the information conceptualized in large sequence alignments, and the challenges in integrating MSAs with multiple orthogonal data such as cancer variants and post-translational modifications, which are often stored in heterogeneous data sources and formats...
October 12, 2016: Molecular BioSystems
Makiko Tsutsumi, Setsuri Yokoi, Fuyuki Miya, Masafumi Miyata, Mitsuhiro Kato, Nobuhiko Okamoto, Tatsuhiko Tsunoda, Mami Yamasaki, Yonehiro Kanemura, Kenjiro Kosaki, Shinji Saitoh, Hiroki Kurahashi
It has been well documented that variants in genes encoding centrosomal proteins cause primary autosomal recessive microcephaly, although the association between centrosomal defects and the etiology of microcephaly syndromes is not fully understood. Polo-like kinase 4 (PLK4) is one of the centrosomal proteins required for centriole duplication. We here describe a patient with microcephaly and chorioretinopathy that harbors compound heterozygous missense variants, c.[442A>G]; [2336G>A], in the PLK4 gene...
December 2016: European Journal of Human Genetics: EJHG
Sze-Wan Li, Yong Liu, Peter B Sampson, Narendra Kumar Patel, Bryan T Forrest, Louise Edwards, Radoslaw Laufer, Miklos Feher, Fuqiang Ban, Donald E Awrey, Richard Hodgson, Irina Beletskaya, Guodong Mao, Jacqueline M Mason, Xin Wei, Xunyi Luo, Reza Kiarash, Erin Green, Tak W Mak, Guohua Pan, Henry W Pauls
Previous efforts from our laboratory demonstrated that (E)-3-((3-(E)-vinylaryl)-1H-indazol-6-yl)methylene)-indolin-2-ones are potent PLK4 inhibitors with in vivo anticancer efficacy upon IP dosing. As part of a continued effort to develop selective and orally efficacious inhibitors, we examined variations on this theme wherein 'directly-linked' aromatics, pendant from the indazole core, replace the arylvinyl moiety. Herein, we describe the design and optimization of this series which was ultimately superseded by (3-aryl-1H-indazol-6-yl)spiro[cyclopropane-1,3'-indolin]-2'-ones...
October 1, 2016: Bioorganic & Medicinal Chemistry Letters
Brian J Galletta, Carey J Fagerstrom, Todd A Schoborg, Tiffany A McLamarrah, John M Ryniawec, Daniel W Buster, Kevin C Slep, Gregory C Rogers, Nasser M Rusan
The centrosome is the major microtubule-organizing centre of many cells, best known for its role in mitotic spindle organization. How the proteins of the centrosome are accurately assembled to carry out its many functions remains poorly understood. The non-membrane-bound nature of the centrosome dictates that protein-protein interactions drive its assembly and functions. To investigate this massive macromolecular organelle, we generated a 'domain-level' centrosome interactome using direct protein-protein interaction data from a focused yeast two-hybrid screen...
August 25, 2016: Nature Communications
Manuel Bauer, Fabien Cubizolles, Alexander Schmidt, Erich A Nigg
Centrioles are essential for the formation of centrosomes and cilia. While numerical and/or structural centrosomes aberrations are implicated in cancer, mutations in centriolar and centrosomal proteins are genetically linked to ciliopathies, microcephaly, and dwarfism. The evolutionarily conserved mechanisms underlying centrosome biogenesis are centered on a set of key proteins, including Plk4, Sas-6, and STIL, whose exact levels are critical to ensure accurate reproduction of centrioles during cell cycle progression...
October 4, 2016: EMBO Journal
Minhee Kim, Brian P O'Rourke, Rajesh Kumar Soni, Prasad V Jallepalli, Ronald C Hendrickson, Meng-Fu Bryan Tsou
PLK4 is the major kinase driving centriole duplication. Duplication occurs only once per cell cycle, forming one new (or daughter) centriole that is tightly engaged to the preexisting (or mother) centriole. Centriole engagement is known to block the reduplication of mother centrioles, but the molecular identity responsible for the block remains unclear. Here, we show that the centriolar cartwheel, the geometric scaffold for centriole assembly, forms the identity of daughter centrioles essential for the block, ceasing further duplication of the mother centriole to which it is engaged...
August 2, 2016: Cell Reports
Zhenhua Li, Kun Dai, Chijuan Wang, Yawen Song, Feng Gu, Fangfang Liu, Li Fu
PURPOSE: Polo-like kinase 4(PLK4) is an important evolutionarily regulator involved in centrosome duplication. We here investigated the expression of PLK4 mRNA and PLK4 in breast cancer, and evaluated its predictive value for response to taxane-based neoadjuvant chemotherapy. METHOD: The PLK4 mRNA expression was measured in breast cancer tissues and corresponding normal breast tissues from 30 breast cancer patients by quantitative real-time polymerase chain reaction (PCR)...
2016: Journal of Cancer
Kathrin Brunk, Mei Zhu, Felix Bärenz, Anne-Sophie Kratz, Uta Haselmann-Weiss, Claude Antony, Ingrid Hoffmann
Centrioles are core components of centrosomes, the major microtubule-organizing centers of animal cells, and act as basal bodies for cilia formation. Control of centriole number is therefore crucial for genome stability and embryogenesis. Centriole duplication requires the serine/threonine protein kinase Plk4. Here, we identify Cep78 as a human centrosomal protein and a new interaction partner of Plk4. Cep78 is mainly a centriolar protein that localizes to the centriolar wall. Furthermore, we find that Plk4 binds to Cep78 through its N-terminal domain but that Cep78 is not an in vitro Plk4 substrate...
July 15, 2016: Journal of Cell Science
S David Hudnall, Hailong Meng, Larissa Lozovatsky, Peining Li, Matthew Strout, Steven H Kleinstein
Genetic analysis of classical Hodgkin lymphoma (cHL) has been hampered by the paucity of Hodgkin cells in biopsies and their poor growth in vitro. However, a wealth of information has been obtained from cHL cell lines. Here we report results of whole-exome sequencing and karyotypic analysis of five cHL cell lines. Four genes with potentially pathogenic single nucleotide variants (SNV) were detected in three cell lines. SNV were also detected in seventeen HL-related genes and three mitosis-related genes. Copy number variants were detected in four HL-related genes in all five cell lines...
April 27, 2016: Leukemia & Lymphoma
Sihem Zitouni, Maria E Francia, Filipe Leal, Susana Montenegro Gouveia, Catarina Nabais, Paulo Duarte, Samuel Gilberto, Daniela Brito, Tyler Moyer, Steffi Kandels-Lewis, Midori Ohta, Daiju Kitagawa, Andrew J Holland, Eric Karsenti, Thierry Lorca, Mariana Lince-Faria, Mónica Bettencourt-Dias
Centrioles are essential for the assembly of both centrosomes and cilia. Centriole biogenesis occurs once and only once per cell cycle and is temporally coordinated with cell-cycle progression, ensuring the formation of the right number of centrioles at the right time. The formation of new daughter centrioles is guided by a pre-existing, mother centriole. The proximity between mother and daughter centrioles was proposed to restrict new centriole formation until they separate beyond a critical distance. Paradoxically, mother and daughter centrioles overcome this distance in early mitosis, at a time when triggers for centriole biogenesis Polo-like kinase 4 (PLK4) and its substrate STIL are abundant...
May 9, 2016: Current Biology: CB
Ryan A Denu, Lauren M Zasadil, Craig Kanugh, Jennifer Laffin, Beth A Weaver, Mark E Burkard
BACKGROUND: Centrosome amplification (CA) has been reported in nearly all types of human cancer and is associated with deleterious clinical factors such as higher grade and stage. However, previous reports have not shown how CA affects cellular differentiation and clinical outcomes in breast cancer. METHODS: We analyzed centrosomes by immunofluorescence and compared to ploidy and chromosomal instability (CIN) as assessed by 6-chromosome FISH in a cohort of 362 breast cancers with median clinical follow-up of 8...
January 29, 2016: BMC Cancer
Jacqueline G Miller, Yan Liu, Christopher W Williams, Harold E Smith, Kevin F O'Connell
Centrioles play critical roles in the organization of microtubule-based structures, from the mitotic spindle to cilia and flagella. In order to properly execute their various functions, centrioles are subjected to stringent copy number control. Central to this control mechanism is a precise duplication event that takes place during S phase of the cell cycle and involves the assembly of a single daughter centriole in association with each mother centriole . Recent studies have revealed that posttranslational control of the master regulator Plk4/ZYG-1 kinase and its downstream effector SAS-6 is key to ensuring production of a single daughter centriole...
January 15, 2016: G3: Genes—Genomes—Genetics
Akiko Hori, Karin Barnouin, Ambrosius P Snijders, Takashi Toda
Centrioles are the major constituents of the animal centrosome, in which Plk4 kinase serves as a master regulator of the duplication cycle. Many eukaryotes also contain numerous peripheral particles known as centriolar satellites. While centriolar satellites aid centriole assembly and primary cilium formation, it is unknown whether Plk4 plays any regulatory roles in centriolar satellite integrity. Here we show that Plk4 is a critical determinant of centriolar satellite organisation. Plk4 depletion leads to the dispersion of centriolar satellites and perturbed ciliogenesis...
March 2016: EMBO Reports
Paula A Coelho, Leah Bury, Marta N Shahbazi, Kifayathullah Liakath-Ali, Peri H Tate, Sam Wormald, Christopher J Hindley, Meritxell Huch, Joy Archer, William C Skarnes, Magdalena Zernicka-Goetz, David M Glover
To address the long-known relationship between supernumerary centrosomes and cancer, we have generated a transgenic mouse that permits inducible expression of the master regulator of centriole duplication, Polo-like-kinase-4 (Plk4). Over-expression of Plk4 from this transgene advances the onset of tumour formation that occurs in the absence of the tumour suppressor p53. Plk4 over-expression also leads to hyperproliferation of cells in the pancreas and skin that is enhanced in a p53 null background. Pancreatic islets become enlarged following Plk4 over-expression as a result of equal expansion of α- and β-cells, which exhibit centrosome amplification...
December 2015: Open Biology
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