Suchergebnisse

Mitosis is largely driven by the highly ordered process of phosphorylation and dephosphorylation. Current estimates from large scale deep phosphor-proteomics analysis suggest that the majority of the proteasome is fully-phosphorylated during mitosis, highlighting the extensive network of events that phosphorylation controls. To better understand these events, we utilised the unique Minardo layout, which displays multi-dimensional information including time which flows around a schematic "circtanglar" cell (Ma et al., 2013). Over 90 events are visually represented on the layout, providing a quick yet comprehensive overview of the key phosphorylation events that regulate entry, progression and exit from mitosis (Burgess et al., 2017). Each phosphorylation event is visually linked to its upstream regulatory kinase or phosphatase, adding an additional layer of information. In addition, the website version (http://www.cell.com/cell/enhanced/odonoghue2), is fully interactive allowing users to click on each phosphosite, with the pop-up box containing direct links to 3D structure, UniProt and most importantly, a simple description along with additional phosphorylation events and direct links to the supporting literature in PubMed. Currently, the information contained within these pop-up boxes is not easily accessible or searchable, limiting its use, consequently in this review we have re-compiled the pop-up boxes to enable easy access to the information and provide a comprehensive compendium of the major phosphorylation events currently known to be essential for mitosis. ; A.B. is supported by CINSW FRL (ID#10/FRL/3-02), The Patricia Helen Guest Fellowship and a NBCF IIRS grant (#IIRS-18-103). S.R. is an Australian Government RTP Scholarship. M.M. is supported by MINECO (SAF2015-69920-R, ERDF-EU, and BFU2014-52125-REDT grants). J.V. and S.I.O'D. are supported by CSIRO's OCE Science Leader programme. The authors thank Benedetta Frida Baldi and Christopher Hammang for creative input.

The E3-ubiquitin ligase APC/C-Cdh1 is essential for endoreduplication but its relevance in the mammalian mitotic cell cycle is still unclear. Here we show that genetic ablation of Cdh1 in the developing nervous system results in hypoplastic brain and hydrocephalus. These defects correlate with enhanced levels of Cdh1 substrates and increased entry into the S phase in neural progenitors. However, cell division is prevented in the absence of Cdh1 due to hyperactivation of cyclin-dependent kinases, replicative stress, induction of p53, G2 arrest and apoptotic death of these progenitor cells. Concomitant ablation of p53 rescues apoptosis but not replicative stress, resulting in the presence of damaged neurons throughout the adult brain. These data indicate that the inactivation of Cdh1 in vivo results in replicative stress, cell cycle arrest and cell death, supporting recent therapeutic proposals aimed to inhibit the APC/C in tumours. ; M.E. was supported by the Spanish Ministry of Economy and Competitiveness (MINECO). This work was funded by grants from the Foundation Ramón Areces and MINECO SAF2012-38215 to M.M.). The Cell Division and Cancer Group of the CNIO are supported by the OncoCycle Programme (S2010/BMD-2470) from the Comunidad de Madrid, the OncoBIO Consolider-Ingenio 2010 Programme (MINECO, CSD2007-00017) and the European Union Seventh Framework Programme (MitoSys project; HEALTH-F5-2010-241548). ; Peer Reviewed

This work is licensed under a Creative Commons Attribution-NonCommercial. ; Cdc14 is an essential phosphatase in yeast but its role in the mammalian cell cycle remains obscure. We report here that Cdc14b-knockout cells display unscheduled induction of multiple cell cycle regulators resulting in early entry into DNA replication and mitosis from quiescence. Cdc14b dephosphorylates Ser5 at the C-terminal domain (CTD) of RNA polymerase II, a major substrate of cyclin-dependent kinases. Lack of Cdc14b results in increased CTD-Ser5 phosphorylation, epigenetic modifications that mark active chromatin, and transcriptional induction of cell cycle regulators. These data suggest a function for mammalian Cdc14 phosphatases in the control of transcription during the cell cycle. ; This work was funded by grants from the Association for International Cancer Research (AICR #08-0188), Foundation Ramón Areces, and the Spanish Ministry of Science and Innovation (MICINN; BFU2008-04293 to M.S.; SAF2009-07973 to M.M.). The Cell Division and Cancer Group of the CNIO is supported by the OncoCycle Programme (S-BIO-0283-2006) from the Comunidad de Madrid, the OncoBIO Consolider-Ingenio 2010 Programme (CSD2007- 00017) from the MICINN, Madrid, and the European Union Seventh Framework Programme (MitoSys project; HEALTH-F5-2010-241548). ; Peer Reviewed

Tumorigenesis induces actin cortex remodeling, which makes cancerous cells softer. Cell deformability is largely determined by myosin-driven cortical tension and actin fiber architecture at the cell cortex. However, it is still unclear what the weight of each contribution is, and how these contributions change during cancer development. Moreover, little attention has been paid to the effect of energy metabolism on this phenomenon and its reprogramming in cancer. Here, we perform precise two-dimensional mechanical phenotyping based on power-law rheology to unveil the contributions of myosin II, actin fiber architecture and energy metabolism to the deformability of healthy (MCF-10A), noninvasive cancerous (MCF-7), and metastatic (MDA-MB-231) human breast epithelial cells. Contrary to the perception that the actin cortex is a passive structure that provides mechanical resistance to the cell, we find that this is only true when the actin cortex is activated by metabolic processes. The results show marked differences in the nature of the active processes that build up cell stiffness, namely that healthy cells use ATP-driven actin polymerization whereas metastatic cells use myosin II activity. Noninvasive cancerous cells exhibit an anomalous behavior, as their stiffness is not as affected by the lack of nutrients and ATP, suggesting that energy metabolism reprogramming is used to sustain active processes at the actin cortex. ; This work was supported by the European Union's Horizon 2020 research and innovation program under European Research Council Grant 681275-LIQUIDMASS-ERCCoG-2015, under Grant Agreement No. 731868 – VIRUSCAN and by the Spanish Science, Innovation and Universities Ministry through project CELLTANGLE reference RTI2018-099369-B-I00; by the Comunidad de Madrid (iLUNG B2017/BMD-3884) with support from EU (FEDER, FSE) and Ramón y Cajal grant RYC-2017-21640 to P.M.K. The service from the X-SEM Laboratory is funded by MCIU (CSIC13-4E-1794) and EU (FEDER, FSE).

The cell cycle is a tightly regulated process that is controlled by the conserved cyclin-dependent kinase (CDK)-cyclin protein complex1. However, control of the G0-to-G1 transition is not completely understood. Here we demonstrate that p38 MAPK gamma (p38γ) acts as a CDK-like kinase and thus cooperates with CDKs, regulating entry into the cell cycle. p38γ shares high sequence homology, inhibition sensitivity and substrate specificity with CDK family members. In mouse hepatocytes, p38γ induces proliferation after partial hepatectomy by promoting the phosphorylation of retinoblastoma tumour suppressor protein at known CDK target residues. Lack of p38γ or treatment with the p38γ inhibitor pirfenidone protects against the chemically induced formation of liver tumours. Furthermore, biopsies of human hepatocellular carcinoma show high expression of p38γ, suggesting that p38γ could be a therapeutic target in the treatment of this disease. ; G.S. (RYC-2009-04972), F.J.C. (RYC-2014-15242), and Y.A.N. (RYC-2015-17438) are investigators of the Ramón y Cajal Program. E.M. and M.T. were awarded La Caixa fellowships and R.R.-B. was a fellow of the Fundación Ramón Areces-UAM and FPU. B.G.-T. is a fellow of the FPI Severo Ochoa CNIC program (SVP-2013-067639). F.J.C. is a Gilead Liver Research Scholar. This work was funded by grants supported in part by funds from the European Regional Development Fund: the European Union's Seventh Framework Programme (FP7/2007-2013) ERC 260464, EFSD/Lilly European Diabetes Research Programme Dr Sabio, 2017 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation (InvestigadoresBBVA-2017) IN[17]_BBM_BAS_0066, MINECO-FEDER SAF2016-79126-R, and Comunidad de Madrid IMMUNOTHERCAN-CM S2010/BMD-2326 and B2017/ BMD-3733 to G.S.; Juan de la Cierva and MINECO SAF2014-61233-JIN to A.T.-L.; the European Community for MSCA-IF-2014-EF-661160-MetAccembly grant to F.F.; Spanish MINECO CTQ2014-59212-P, European Community for CIG project (PCIG14-GA-2013-630978), and European Research Council (ERC) under the European Union's Horizon 2020 (ERC-2015-StG-679001- NetMoDEzyme) to S.O.; the German Research Foundation (SFB/TRR57/P04 and DFG NE 2128/2-1) and MINECO SAF2017-87919R to Y.A.N.; EXOHEP-CM S2017/BMD-3727 and the COST Action CA17112, MINECO SAF2016-78711, and the AMMF Cholangiocarcinoma Charity 2018/117 to F.J.C.; MINECO (SAF2015-69920-R co-funded by ERDF-EU), the Consolider-Ingenio 2010 Programme (SAF2014-57791-REDC), Excellence Network CellSYS (BFU2014- 52125-REDT), and the iLUNG Programme (B2017/BMD-3884) from the Comunidad de Madrid to M. Malumbres; MINECO SAF2015-67077-R and SAF2017-89901-R to J.B.; MINECO (BIO2015-67580-P), Carlos III Institute of Health-Fondo de Investigación Sanitaria (ProteoRed PRB3, IPT17/0019 - ISCIII-SGEFI/ERDF), Fundación La Marató and 'La Caixa' Banking Foundation (HR17-00247) to J.V.; ISCIII and FEDER PI16/01548 and Junta de Castilla y León GRS 1362/A/16 and INT/M/17/17 to M. Marcos; Junta de Castilla y León GRS 1356/A/16 and GRS 1587/A/17 to J.L.-T.; and MCNU (SAF2017- 84494-C2-1-R) to J.R.-C. The CNIC is supported by the Ministerio de Ciencia, Innovación y Universidades (MCNU) and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505). ; Sí