Activity of the APCCdh1 form of the anaphase-promoting complex persists until S phase and prevents the premature expression of Cdc20p

Cell cycle progression is driven by waves of cyclin expression coupled with regulated protein degradation. An essential step for initiating mitosis is the inactivation of proteolysis mediated by the anaphase-promoting complex/cyclosome (APC/C) bound to its regulator Cdh1p/Hct1p. Yeast APCCdh1 was proposed previously to be inactivated at Start by G1 cyclin/cyclin-dependent kinase (CDK). Here, we demonstrate that in a normal cell cycle APCCdh1 is inactivated in a graded manner and is not extinguished until S phase. Complete inactivation of APCCdh1 requires S phase cyclins. Further, persistent APCCdh1 activity throughout G1 helps to ensure the proper timing of Cdc20p expression. This suggests that S phase cyclins have an important role in allowing the accumulation of mitotic cyclins and further suggests a regulatory loop among S phase cyclins, APCCdh1, and APCCdc20.

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A Protein Encoded by the Latency-Related Gene of Bovine Herpesvirus 1 Is Expressed in Trigeminal Ganglionic Neurons of Latently Infected Cattle and Interacts with Cyclin-Dependent Kinase 2 during Productive Infection

Journal of Virology ◽

10.1128/jvi.72.10.8133-8142.1998 ◽

1998 ◽

Vol 72 (10) ◽

pp. 8133-8142 ◽

Cited By ~ 43

Author(s):

Yunquan Jiang ◽

Ashfaque Hossain ◽

Maria Teresa Winkler ◽

Todd Holt ◽

Alan Doster ◽

...

Keyword(s):

Cell Cycle ◽

Cell Cycle Progression ◽

Acute Infection ◽

Cyclin A ◽

S Phase ◽

Cyclin Dependent Kinase ◽

Bovine Herpesvirus 1 ◽

Cycle Progression ◽

Latently Infected ◽

Herpesvirus 1

ABSTRACT Despite productive viral gene expression in the peripheral nervous system during acute infection, the bovine herpesvirus 1 (BHV-1) infection cycle is blocked in sensory ganglionic neurons and consequently latency is established. The only abundant viral transcript expressed during latency is the latency-related (LR) RNA. LR gene products inhibit S-phase entry, and binding of the LR protein (LRP) to cyclin A was hypothesized to block cell cycle progression. This study demonstrates LRP is a nuclear protein which is expressed in neurons of latently infected cattle. Affinity chromatography indicated that LRP interacts with cyclin-dependent kinase 2 (cdk2)-cyclin complexes or cdc2-cyclin complexes in transfected human cells or infected bovine cells. After partial purification using three different columns (DEAE-Sepharose, Econo S, and heparin-agarose), LRP was primarily associated with cdk2-cyclin E complexes, an enzyme which is necessary for G1-to-S-phase cell cycle progression. During acute infection of trigeminal ganglia or following dexamethasone-induced reactivation, BHV-1 induces expression of cyclin A in neurons (L. M. Schang, A. Hossain, and C. Jones, J. Virol. 70:3807–3814, 1996). Expression of S-phase regulatory proteins (cyclin A, for example) leads to neuronal apoptosis. Consequently, we hypothesize that interactions between LRP and cell cycle regulatory proteins promote survival of postmitotic neurons during acute infection and/or reactivation.

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The RASSF1A Tumor Suppressor Restrains Anaphase-Promoting Complex/Cyclosome Activity during the G1/S Phase Transition To Promote Cell Cycle Progression in Human Epithelial Cells

Molecular and Cellular Biology ◽

10.1128/mcb.02291-07 ◽

2008 ◽

Vol 28 (10) ◽

pp. 3190-3197 ◽

Cited By ~ 19

Author(s):

Angelique W. Whitehurst ◽

Rosalyn Ram ◽

Latha Shivakumar ◽

Boning Gao ◽

John D. Minna ◽

...

Keyword(s):

Phase Transition ◽

Cell Cycle ◽

Tumor Suppressor ◽

Epithelial Cells ◽

Cyclin D1 ◽

Cell Cycle Progression ◽

S Phase ◽

Phase Cell ◽

Anaphase Promoting Complex ◽

Cycle Progression

ABSTRACT Multiple molecular lesions in human cancers directly collaborate to deregulate proliferation and suppress apoptosis to promote tumorigenesis. The candidate tumor suppressor RASSF1A is commonly inactivated in a broad spectrum of human tumors and has been implicated as a pivotal gatekeeper of cell cycle progression. However, a mechanistic account of the role of RASSF1A gene inactivation in tumor initiation is lacking. Here we have employed loss-of-function analysis in human epithelial cells for a detailed investigation of the contribution of RASSF1 to cell cycle progression. We found that RASSF1A has dual opposing regulatory connections to G1/S phase cell cycle transit. RASSF1A associates with the Ewing sarcoma breakpoint protein, EWS, to limit accumulation of cyclin D1 and restrict exit from G1. Surprisingly, we found that RASSF1A is also required to restrict SCFβTrCP activity to allow G/S phase transition. This restriction is required for accumulation of the anaphase-promoting complex/cyclosome (APC/C) inhibitor Emi1 and the concomitant block of APC/C-dependent cyclin A turnover. The consequence of this relationship is inhibition of cell cycle progression in normal epithelial cells upon RASSF1A depletion despite elevated cyclin D1 concentrations. Progression to tumorigenicity upon RASSF1A gene inactivation should therefore require collaborating genetic aberrations that bypass the consequences of impaired APC/C regulation at the G1/S phase cell cycle transition.

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Differential induction of ‘metabolic genes’ after mitogen stimulation and during normal cell cycle progression

Journal of Cell Science ◽

10.1242/jcs.107.1.241 ◽

1994 ◽

Vol 107 (1) ◽

pp. 241-252 ◽

Cited By ~ 1

Author(s):

C. Burger ◽

M. Wick ◽

S. Brusselbach ◽

R. Muller

Keyword(s):

Cell Cycle ◽

Normal Cell ◽

Cell Cycle Progression ◽

S Phase ◽

Cycle Progression ◽

Genes Encoding ◽

A Cell ◽

Induced Genes ◽

Cycle Dependent ◽

Normal Cell Cycle

Mitogenic stimulation of quiescent cells not only triggers the cell division cycle but also induces an increase in cell volume, associated with an activation of cellular metabolism. It is therefore likely that genes encoding enzymes and other proteins involved in energy metabolism and biosynthetic pathways represent a major class of mitogen-induced genes. In the present study, we investigated in the non-established human fibroblast line WI-38 the induction by mitogens of 17 genes whose products play a role in different metabolic processes. We show that these genes fall into 4 different categories, i.e. non-induced genes, immediate early (IE) primary genes, delayed early (DE) secondary genes and late genes reaching peak levels in S-phase. In addition, we have analysed the regulation of these genes during normal cell cycle progression, using HL-60 cells separated by counterflow elutriation. A clear cell cycle regulation was seen with those genes that are induced in S-phase, i.e. thymidine kinase, thymidylate synthase and dihydrofolate reductase. In addition, two DE genes showed a cell cycle dependent expression. Ornithine decarboxylase mRNA increased around mid-G1, reaching maximum levels in S/G2, while hexokinase mRNA expression was highest in early G1. In contrast, the expression of other DE and IE genes did not fluctuate during the cell cycle, a result that was confirmed with elutriated WI-38 and serum-stimulated HL-60 cells. These observations suggest that G0-->S and G1-->S transition are distinct processes, exhibiting characteristic programmes of gene regulation, and merging around S-phase entry.

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Cortactin Modulates RhoA Activation and Expression of Cip/Kip Cyclin-Dependent Kinase Inhibitors To Promote Cell Cycle Progression in 11q13-Amplified Head and Neck Squamous Cell Carcinoma Cells

Molecular and Cellular Biology ◽

10.1128/mcb.00249-10 ◽

2010 ◽

Vol 30 (21) ◽

pp. 5057-5070 ◽

Cited By ~ 17

Author(s):

David R. Croucher ◽

Danny Rickwood ◽

Carole M. Tactacan ◽

Elizabeth A. Musgrove ◽

Roger J. Daly

Keyword(s):

Cell Cycle ◽

Squamous Cell Carcinoma ◽

Cell Carcinoma ◽

Cell Cycle Progression ◽

Kinase Inhibitors ◽

S Phase ◽

Cyclin Dependent Kinase ◽

Cycle Progression ◽

Fadu Cells ◽

Phase Entry

ABSTRACT The cortactin oncoprotein is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC), often due to amplification of the encoding gene (CTTN). While cortactin overexpression enhances invasive potential, recent research indicates that it also promotes cell proliferation, but how cortactin regulates the cell cycle machinery is unclear. In this article we report that stable short hairpin RNA-mediated cortactin knockdown in the 11q13-amplified cell line FaDu led to increased expression of the Cip/Kip cyclin-dependent kinase inhibitors (CDKIs) p21WAF1/Cip1, p27Kip1, and p57Kip2 and inhibition of S-phase entry. These effects were associated with increased binding of p21WAF1/Cip1 and p27Kip1 to cyclin D1- and E1-containing complexes and decreased retinoblastoma protein phosphorylation. Cortactin regulated expression of p21WAF1/Cip1 and p27Kip1 at the transcriptional and posttranscriptional levels, respectively. The direct roles of p21WAF1/Cip1, p27Kip1, and p57Kip2 downstream of cortactin were confirmed by the transient knockdown of each CDKI by specific small interfering RNAs, which led to partial rescue of cell cycle progression. Interestingly, FaDu cells with reduced cortactin levels also exhibited a significant diminution in RhoA expression and activity, together with decreased expression of Skp2, a critical component of the SCF ubiquitin ligase that targets p27Kip1 and p57Kip2 for degradation. Transient knockdown of RhoA in FaDu cells decreased expression of Skp2, enhanced the level of Cip/Kip CDKIs, and attenuated S-phase entry. These findings identify a novel mechanism for regulation of proliferation in 11q13-amplified HNSCC cells, in which overexpressed cortactin acts via RhoA to decrease expression of Cip/Kip CDKIs, and highlight Skp2 as a downstream effector for RhoA in this process.

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A Cds1-Mediated Checkpoint Protects the MBF Activator Rep2 from Ubiquitination by Anaphase-Promoting Complex/Cyclosome-Ste9 at S-Phase Arrest in Fission Yeast

Molecular and Cellular Biology ◽

10.1128/mcb.00562-09 ◽

2009 ◽

Vol 29 (18) ◽

pp. 4959-4970 ◽

Cited By ~ 8

Author(s):

Zhaoqing Chu ◽

Majid Eshaghi ◽

Suk Yean Poon ◽

Jianhua Liu

Keyword(s):

Cell Cycle ◽

Cell Cycle Progression ◽

Transcriptional Activity ◽

S Phase ◽

Anaphase Promoting Complex ◽

Cell Recovery ◽

Cycle Progression ◽

Phase Arrest ◽

S Phase Arrest

ABSTRACT Transcription of the MluI cell cycle box (MCB) motif-containing genes at G1 phase is regulated by the MCB-binding factors (MBF) (also called DSC1) in Schizosaccharomyces pombe. Upon S-phase arrest, the MBF transcriptional activity is induced through the accumulation of the MBF activator Rep2. In this study, we show that the turnover of Rep2 is attributable to ubiquitin-mediated proteolysis. Levels of Rep2 oscillate during the cell cycle, with a peak at G1 phase, coincident with the MBF activity. Furthermore, we show that Rep2 ubiquitination requires the function of the E3 ligase anaphase-promoting complex/cyclosome (APC/C). Ste9 can be phosphorylated by the checkpoint kinase Cds1 in vitro, and its inhibition/phosphorylation at S-phase arrest is dependent on the function of Cds1. Our data indicate that the Cds1-dependent stabilization of Rep2 is achieved through the inhibition/phosphorylation of APC/C-Ste9 at the onset of S-phase arrest. Stabilization of Rep2 is important for stimulating transcription of the MBF-dependent genes to ensure a sufficient supply of proteins essential for cell recovery from S-phase arrest. We propose that oscillation of Rep2 plays a role in regulation of periodic transcription of the MBF-dependent genes during cell cycle progression.

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Golgi-associated RhoBTB3 targets Cyclin E for ubiquitylation and promotes cell cycle progression

The Journal of Cell Biology ◽

10.1083/jcb.201305158 ◽

2013 ◽

Vol 203 (2) ◽

pp. 233-250 ◽

Cited By ~ 28

Author(s):

Albert Lu ◽

Suzanne R. Pfeffer

Keyword(s):

Cell Cycle ◽

Cell Cycle Progression ◽

Cyclin E ◽

Cell Cycle Control ◽

S Phase ◽

Cycle Progression ◽

Ubiquitin Ligase Complex ◽

Golgi Fragmentation ◽

Ring E3 ◽

Normal Cell Cycle

Cyclin E regulates the cell cycle transition from G1 to S phase and is degraded before entry into G2 phase. Here we show that RhoBTB3, a Golgi-associated, Rho-related ATPase, regulates the S/G2 transition of the cell cycle by targeting Cyclin E for ubiquitylation. Depletion of RhoBTB3 arrested cells in S phase, triggered Golgi fragmentation, and elevated Cyclin E levels. On the Golgi, RhoBTB3 bound Cyclin E as part of a Cullin3 (CUL3)-dependent RING–E3 ubiquitin ligase complex comprised of RhoBTB3, CUL3, and RBX1. Golgi association of this complex was required for its ability to catalyze Cyclin E ubiquitylation and allow normal cell cycle progression. These experiments reveal a novel role for a Ras superfamily member in catalyzing Cyclin E turnover during S phase, as well as an unexpected, essential role for the Golgi as a ubiquitylation platform for cell cycle control.

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The Stress-activated Protein Kinase Hog1 Mediates S Phase Delay in Response to Osmostress

Molecular Biology of the Cell ◽

10.1091/mbc.e09-02-0129 ◽

2009 ◽

Vol 20 (15) ◽

pp. 3572-3582 ◽

Cited By ~ 42

Author(s):

Gilad Yaakov ◽

Alba Duch ◽

María García-Rubio ◽

Josep Clotet ◽

Javier Jimenez ◽

...

Keyword(s):

Cell Cycle ◽

Cell Cycle Progression ◽

Kinase Activity ◽

S Phase ◽

Cyclin Dependent Kinase ◽

Cycle Progression ◽

Replication Complex ◽

Extracellular Stimuli ◽

Phase Progression ◽

Cell Cycle Machinery

Control of cell cycle progression by stress-activated protein kinases (SAPKs) is essential for cell adaptation to extracellular stimuli. Exposure of yeast to osmostress activates the Hog1 SAPK, which modulates cell cycle progression at G1 and G2 by the phosphorylation of elements of the cell cycle machinery, such as Sic1 and Hsl1, and by down-regulation of G1 and G2 cyclins. Here, we show that upon stress, Hog1 also modulates S phase progression. The control of S phase is independent of the S phase DNA damage checkpoint and of the previously characterized Hog1 cell cycle targets Sic1 and Hsl1. Hog1 uses at least two distinct mechanisms in its control over S phase progression. At early S phase, the SAPK prevents firing of replication origins by delaying the accumulation of the S phase cyclins Clb5 and Clb6. In addition, Hog1 prevents S phase progression when activated later in S phase or cells containing a genetic bypass for cyclin-dependent kinase activity. Hog1 interacts with components of the replication complex and delays phosphorylation of the Dpb2 subunit of the DNA polymerase. The two mechanisms of Hog1 action lead to delayed firing of origins and prolonged replication, respectively. The Hog1-dependent delay of replication could be important to allow Hog1 to induce gene expression before replication.

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Cyclin-dependent kinase control of motile ciliogenesis

eLife ◽

10.7554/elife.36375 ◽

2018 ◽

Vol 7 ◽

Cited By ~ 16

Author(s):

Eszter K Vladar ◽

Miranda B Stratton ◽

Maxwell L Saal ◽

Glicella Salazar-De Simone ◽

Xiangyuan Wang ◽

...

Keyword(s):

Cell Cycle ◽

Dna Replication ◽

Cell Cycle Progression ◽

S Phase ◽

Cell Cycle Regulators ◽

Airway Epithelial ◽

Cyclin Dependent Kinase ◽

Cycle Progression ◽

Multiciliated Cells ◽

Cell Cycle Machinery

Cycling cells maintain centriole number at precisely two per cell in part by limiting their duplication to S phase under the control of the cell cycle machinery. In contrast, postmitotic multiciliated cells (MCCs) uncouple centriole assembly from cell cycle progression and produce hundreds of centrioles in the absence of DNA replication to serve as basal bodies for motile cilia. Although some cell cycle regulators have previously been implicated in motile ciliogenesis, how the cell cycle machinery is employed to amplify centrioles is unclear. We use transgenic mice and primary airway epithelial cell culture to show that Cdk2, the kinase responsible for the G1 to S phase transition, is also required in MCCs to initiate motile ciliogenesis. While Cdk2 is coupled with cyclins E and A2 during cell division, cyclin A1 is required during ciliogenesis, contributing to an alternative regulatory landscape that facilitates centriole amplification without DNA replication.

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The PP2A-B56 Phosphatase Opposes Cyclin E Autocatalytic Degradation via Site-Specific Dephosphorylation

Molecular and Cellular Biology ◽

10.1128/mcb.00657-16 ◽

2017 ◽

Vol 37 (8) ◽

Cited By ~ 5

Author(s):

Ryan J. Davis ◽

Jherek Swanger ◽

Bridget T. Hughes ◽

Bruce E. Clurman

Keyword(s):

Cell Cycle ◽

Ubiquitin Ligase ◽

Cell Cycle Progression ◽

Cyclin E ◽

Phosphorylation Site ◽

S Phase ◽

Cyclin Dependent Kinase ◽

Cycle Progression ◽

Cdk2 Activity ◽

Interphase Cells

ABSTRACT Cyclin E, in conjunction with its catalytic partner cyclin-dependent kinase 2 (CDK2), regulates cell cycle progression as cells exit quiescence and enter S-phase. Multiple mechanisms control cyclin E periodicity during the cell cycle, including phosphorylation-dependent cyclin E ubiquitylation by the SCFFbw7 ubiquitin ligase. Serine 384 (S384) is the critical cyclin E phosphorylation site that stimulates Fbw7 binding and cyclin E ubiquitylation and degradation. Because S384 is autophosphorylated by bound CDK2, this presents a paradox as to how cyclin E can evade autocatalytically induced degradation in order to phosphorylate its other substrates. We found that S384 phosphorylation is dynamically regulated in cells and that cyclin E is specifically dephosphorylated at S384 by the PP2A-B56 phosphatase, thereby uncoupling cyclin E degradation from cyclin E-CDK2 activity. Furthermore, the rate of S384 dephosphorylation is high in interphase but low in mitosis. This provides a mechanism whereby interphase cells can oppose autocatalytic cyclin E degradation and maintain cyclin E-CDK2 activity while also enabling cyclin E destruction in mitosis, when inappropriate cyclin E expression is genotoxic.

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Budding yeast relies on G1 cyclin specificity to couple cell cycle progression with morphogenetic development

Science Advances ◽

10.1126/sciadv.abg0007 ◽

2021 ◽

Vol 7 (23) ◽

pp. eabg0007

Author(s):

Deniz Pirincci Ercan ◽

Florine Chrétien ◽

Probir Chakravarty ◽

Helen R. Flynn ◽

Ambrosius P. Snijders ◽

...

Keyword(s):

Cell Cycle ◽

Cell Cycle Progression ◽

Budding Yeast ◽

Quantitative Model ◽

Cyclin Dependent Kinase ◽

Cycle Progression ◽

Model Cell ◽

Mitotic Cyclin ◽

Substrate Phosphorylation ◽

The Cost

Two models have been put forward for cyclin-dependent kinase (Cdk) control of the cell cycle. In the qualitative model, cell cycle events are ordered by distinct substrate specificities of successive cyclin waves. Alternatively, in the quantitative model, the gradual rise of Cdk activity from G1 phase to mitosis leads to ordered substrate phosphorylation at sequential thresholds. Here, we study the relative contributions of qualitative and quantitative Cdk control in Saccharomyces cerevisiae. All S phase and mitotic cyclins can be replaced by a single mitotic cyclin, albeit at the cost of reduced fitness. A single cyclin can also replace all G1 cyclins to support ordered cell cycle progression, fulfilling key predictions of the quantitative model. However, single-cyclin cells fail to polarize or grow buds and thus cannot survive. Our results suggest that budding yeast has become dependent on G1 cyclin specificity to couple cell cycle progression to essential morphogenetic events.

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