Induction of UGT1A1 and CYP2B6 by an Antimitogenic Factor in HepG2 Cells Is Mediated through Suppression of Cyclin-Dependent Kinase 2 Activity: Cell Cycle-Dependent Expression

2009 ◽  
Vol 38 (1) ◽  
pp. 177-186 ◽  
Author(s):  
Junko Sugatani ◽  
Makoto Osabe ◽  
Masatoshi Kurosawa ◽  
Naomi Kitamura ◽  
Akira Ikari ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Hepg2 Cells ◽  
Cyclin Dependent Kinase ◽  
Cycle Dependent

scholarly journals Cdk1 promotes cytokinesis in fission yeast through activation of the septation initiation network

2014 ◽  
Vol 25 (15) ◽  
pp. 2250-2259 ◽  
Author(s):  
Nicole Rachfall ◽  
Alyssa E. Johnson ◽  
Sapna Mehta ◽  
Jun-Song Chen ◽  
Kathleen L. Gould
Keyword(s):  
Cell Cycle ◽  
Spindle Pole Body ◽  
Complete Removal ◽  
Spindle Pole ◽  
Cyclin Dependent Kinase ◽  
Gtpase Activating Protein ◽  
Pole Body ◽  
Kinase Cascade ◽  
Septation Initiation Network ◽  
Cycle Dependent

In Schizosaccharomyces pombe, late mitotic events are coordinated with cytokinesis by the septation initiation network (SIN), an essential spindle pole body (SPB)–associated kinase cascade, which controls the formation, maintenance, and constriction of the cytokinetic ring. It is not fully understood how SIN initiation is temporally regulated, but it depends on the activation of the GTPase Spg1, which is inhibited during interphase by the essential bipartite GTPase-activating protein Byr4-Cdc16. Cells are particularly sensitive to the modulation of Byr4, which undergoes cell cycle–dependent phosphorylation presumed to regulate its function. Polo-like kinase, which promotes SIN activation, is partially responsible for Byr4 phosphorylation. Here we show that Byr4 is also controlled by cyclin-dependent kinase (Cdk1)–mediated phosphorylation. A Cdk1 nonphosphorylatable Byr4 phosphomutant displays severe cell division defects, including the formation of elongated, multinucleate cells, failure to maintain the cytokinetic ring, and compromised SPB association of the SIN kinase Cdc7. Our analyses show that Cdk1-mediated phosphoregulation of Byr4 facilitates complete removal of Byr4 from metaphase SPBs in concert with Plo1, revealing an unexpected role for Cdk1 in promoting cytokinesis through activation of the SIN pathway.

scholarly journals Biochemical analyses reveal amino acid residues critical for cell cycle-dependent phosphorylation of human Cdc14A phosphatase by cyclin-dependent kinase 1

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Sara Ovejero ◽  
Patricia Ayala ◽  
Marcos Malumbres ◽  
Felipe X. Pimentel-Muiños ◽  
Avelino Bueno ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Amino Acid ◽  
Amino Acid Residues ◽  
Cyclin Dependent Kinase ◽  
Biochemical Analyses ◽  
Cycle Dependent

scholarly journals Two distinct ubiquitin-proteolysis pathways in the fission yeast cell cycle

1999 ◽  
Vol 354 (1389) ◽  
pp. 1551-1557 ◽  
Author(s):  
Takashi Toda ◽  
Itziar Ochotorena ◽  
Kin-ichiro Kominami
Keyword(s):  
Cell Cycle ◽  
Fission Yeast ◽  
Cell Cycle Control ◽  
Eukaryotic Cell ◽  
Cdk Inhibitor ◽  
Cyclin Dependent Kinase ◽  
Anaphase Promoting Complex ◽  
Repeat Proteins ◽  
Cycle Dependent ◽  
Universal Mechanism

The SCF complex (Skp1-Cullin-1-F-box) and the APC/cyclosome (anaphase-promoting complex) are two ubiquitin ligases that play a crucial role in eukaryotic cell cycle control. In fission yeast F-box/WD-repeat proteins Pop1 and Pop2, components of SCF are required for cell-cycle-dependent degradation of the cyclin-dependent kinase (CDK) inhibitor Rum1 and the S-phase regulator Cdc18. Accumulation of these proteins in pop1 and pop2 mutants leads to re-replication and defects in sexual differentiation. Despite structural and functional similarities, Pop1 and Pop2 are not redundant homologues. Instead, these two proteins form heterodimers as well as homodimers, such that three distinct complexes, namely SCF Pop1/Pop1 , SCF Pop1/Pop2 and SCF Pop2/Pop2 , appear to exist in the cell. The APC/cyclosome is responsible for inactivation of CDK/cyclins through the degradation of B-type cyclins. We have identified two novel components or regulators of this complex, called Apc10 and Ste9, which are evolutionarily highly conserved. Apc10 (and Ste9), together with Rum1, are required for the establishment of and progression through the G1 phase in fission yeast. We propose that dual downregulation of CDK, one via the APC/cyclosome and the other via the CDK inhibitor, is a universal mechanism that is used to arrest the cell cycle at G1.

scholarly journals The accumulation of an E2F-p130 transcriptional repressor distinguishes a G0 cell state from a G1 cell state.

1996 ◽  
Vol 16 (12) ◽  
pp. 6965-6976 ◽  
Author(s):  
E J Smith ◽  
G Leone ◽  
J DeGregori ◽  
L Jakoi ◽  
J R Nevins
Keyword(s):  
Cell Cycle ◽  
Target Genes ◽  
Kinase Activity ◽  
Transcriptional Repressor ◽  
Negative Control ◽  
Cyclin Dependent Kinase ◽  
Cell State ◽  
Quiescent Cells ◽  
Cycle Dependent ◽  
E2f Proteins

Previous studies have demonstrated cell cycle-dependent specificities in the interactions of E2F proteins with Rb family members. We now show that the formation of an E2F-p130 complex is unique to cells in a quiescent, G0 state. The E2F-p130 complex does not reform when cells reenter a proliferative state and cycle through G1. The presence of an E2F-p130 complex in quiescent cells coincides with the E2F-mediated repression of transcription of the E2F1 gene, and we show that the E2F sites in the E2F1 promoter are important as cells enter quiescence but play no apparent role in cycling cells. In addition, the decay of the E2F-p130 complex as cells reenter the cell cycle requires the action of G1 cyclin-dependent kinase activity. We conclude that the accumulation of the E2F-p130 complex in quiescent cells provides a negative control of certain key target genes and defines a functional distinction between these G0 cells and cells that exist transiently in G1.

scholarly journals Regulation of Cell Cycle-Specific Gene Expression through Cyclin-Dependent Kinase-Mediated Phosphorylation of the Forkhead Transcription Factor Fkh2p

2004 ◽  
Vol 24 (22) ◽  
pp. 10036-10046 ◽  
Author(s):  
Aline Pic-Taylor ◽  
Zoulfia Darieva ◽  
Brian A. Morgan ◽  
Andrew D. Sharrocks
Keyword(s):  
Cell Cycle ◽  
Transcription Factor ◽  
Specific Gene ◽  
Cyclin Dependent Kinase ◽  
Forkhead Transcription Factor ◽  
Cyclin Dependent Kinases ◽  
Regulated Expression ◽  
Dependent Protein ◽  
Cycle Dependent ◽  
Regulation Of Cell Cycle

ABSTRACT The forkhead transcription factor Fkh2p acts in a DNA-bound complex with Mcm1p and the coactivator Ndd1p to regulate cell cycle-dependent expression of the CLB2 gene cluster in Saccharomyces cerevisiae. Here, we demonstrate that Fkh2p is a target of cyclin-dependent protein kinases and that phosphorylation of Fkh2p promotes interactions between Fkh2p and the coactivator Ndd1p. These phosphorylation-dependent changes in the Fkh2p-Ndd1p complex play an important role in the cell cycle-regulated expression of the CLB2 cluster. Our data therefore identify an important regulatory target for cyclin-dependent kinases in the cell cycle and further our molecular understanding of the key cell cycle regulatory transcription factor Fkh2p.

scholarly journals Phosphorylation of ORC2 Protein Dissociates Origin Recognition Complex from Chromatin and Replication Origins

2012 ◽  
Vol 287 (15) ◽  
pp. 11891-11898 ◽  
Author(s):  
Kyung Yong Lee ◽  
Sung Woong Bang ◽  
Sang Wook Yoon ◽  
Seung-Hoon Lee ◽  
Jong-Bok Yoon ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Origin Recognition Complex ◽  
S Phase ◽  
Cyclin Dependent Kinase ◽  
Replication Origins ◽  
Eukaryotic Chromosome ◽  
M Phase ◽  
Cycle Dependent ◽  
Prereplicative Complex ◽  
Origin Recognition

During the late M to the G1 phase of the cell cycle, the origin recognition complex (ORC) binds to the replication origin, leading to the assembly of the prereplicative complex for subsequent initiation of eukaryotic chromosome replication. We found that the cell cycle-dependent phosphorylation of human ORC2, one of the six subunits of ORC, dissociates ORC2, -3, -4, and -5 (ORC2–5) subunits from chromatin and replication origins. Phosphorylation at Thr-116 and Thr-226 of ORC2 occurs by cyclin-dependent kinase during the S phase and is maintained until the M phase. Phosphorylation of ORC2 at Thr-116 and Thr-226 dissociated the ORC2–5 from chromatin. Consistent with this, the phosphomimetic ORC2 protein exhibited defective binding to replication origins as well as to chromatin, whereas the phosphodefective protein persisted in binding throughout the cell cycle. These results suggest that the phosphorylation of ORC2 dissociates ORC from chromatin and replication origins and inhibits binding of ORC to newly replicated DNA.

scholarly journals CDK Family PROTAC Profiling Reveals Distinct Kinetic Responses and Cell Cycle–Dependent Degradation of CDK2

2020 ◽  
pp. 247255522097360
Author(s):  
Kristin M. Riching ◽  
Marie K. Schwinn ◽  
James D. Vasta ◽  
Matthew B. Robers ◽  
Thomas Machleidt ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Ternary Complex ◽  
Cellular Systems ◽  
Cyclin Dependent Kinase ◽  
Cell Cycle Protein ◽  
Degradation Study ◽  
Minimal Loss ◽  
Degradation Rates ◽  
Mechanistic Investigation ◽  
Cycle Dependent

Targeted protein degradation using heterobifunctional proteolysis-targeting chimera (PROTAC) compounds, which recruit E3 ligase machinery to a target protein, is increasingly becoming an attractive pharmacologic strategy. PROTAC compounds are often developed from existing inhibitors, and assessing selectivity is critical for understanding on-target and off-target degradation. We present here an in-depth kinetic degradation study of the pan-kinase PROTAC, TL12-186, applied to 16 members of the cyclin-dependent kinase (CDK) family. Each CDK family member was endogenously tagged with the 11-amino-acid HiBiT peptide, allowing for live cell luminescent monitoring of degradation. Using this approach, we found striking differences and patterns in kinetic degradation rates, potencies, and Dmax values across the CDK family members. Analysis of the responses revealed that most of the CDKs showed rapid and near complete degradation, yet all cell cycle–associated CDKs (1, 2, 4, and 6) showed multimodal and partial degradation. Further mechanistic investigation of the key cell cycle protein CDK2 was performed and revealed CDK2 PROTAC-dependent degradation in unsynchronized or G1-arrested cells but minimal loss in S or G2/M arrest. The ability of CDK2 to form the PROTAC-mediated ternary complex with CRBN in only G1-arrested cells matched these trends, despite binding of CDK2 to TL12-186 in all phases. These data indicate that target subpopulation degradation can occur, dictated by the formation of the ternary complex. These studies additionally underscore the importance of profiling degradation compounds in cellular systems where complete pathways are intact and target proteins can be characterized in their relevant complexes.

Cell cycle–dependent regulation of mitochondrial preprotein translocase

Science ◽  
2014 ◽  
Vol 346 (6213) ◽  
pp. 1109-1113 ◽  
Author(s):  
Angelika B. Harbauer ◽  
Magdalena Opalińska ◽  
Carolin Gerbeth ◽  
Josip S. Herman ◽  
Sanjana Rao ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Protein Import ◽  
Respiratory Activity ◽  
Mitochondrial Protein ◽  
Cyclin Dependent Kinase ◽  
Mitochondrial Protein Import ◽  
Cellular Energy ◽  
Specific Manner ◽  
A Cell ◽  
Cycle Dependent

Mitochondria play central roles in cellular energy conversion, metabolism, and apoptosis. Mitochondria import more than 1000 different proteins from the cytosol. It is unknown if the mitochondrial protein import machinery is connected to the cell division cycle. We found that the cyclin-dependent kinase Cdk1 stimulated assembly of the main mitochondrial entry gate, the translocase of the outer membrane (TOM), in mitosis. The molecular mechanism involved phosphorylation of the cytosolic precursor of Tom6 by cyclin Clb3-activated Cdk1, leading to enhanced import of Tom6 into mitochondria. Tom6 phosphorylation promoted assembly of the protein import channel Tom40 and import of fusion proteins, thus stimulating the respiratory activity of mitochondria in mitosis. Tom6 phosphorylation provides a direct means for regulating mitochondrial biogenesis and activity in a cell cycle-specific manner.

scholarly journals A Pcl-Like Cyclin of Aspergillus nidulans Is Transcriptionally Activated by Developmental Regulators and Is Involved in Sporulation

2001 ◽  
Vol 21 (12) ◽  
pp. 4075-4088 ◽  
Author(s):  
Niklas Schier ◽  
Ralf Liese ◽  
Reinhard Fischer
Keyword(s):  
Cell Cycle ◽  
Aspergillus Nidulans ◽  
Developmental Regulation ◽  
Ectopic Expression ◽  
Cyclin Dependent Kinase ◽  
Direct Role ◽  
Developmental Mutant ◽  
Cycle Dependent ◽  
Late Stages

ABSTRACT The filamentous fungus Aspergillus nidulansreproduces asexually through the formation of spores on a multicellular aerial structure, called a conidiophore. A key regulator of asexual development is the TFIIIA-type zinc finger containing transcriptional activator Bristle (BRLA). Besides BRLA, the transcription factor ABAA, which is located downstream of BRLA in the developmental regulation cascade, is necessary to direct later gene expression during sporulation. We isolated a new developmental mutant and identified a leaky brlA mutation and the mutatedSaccharomyces cerevisiae cyclin homologuepclA, both contributing to the developmental phenotype of the mutant. pclA was found to be 10-fold transcriptionally upregulated during conidiation, and apclA deletion strain was reduced three- to fivefold in production of conidia. Expression of pclA was strongly induced by ectopic expression of brlA orabaA under conidiation-suppressing conditions, indicating a direct role for brlA andabaA in pclA regulation. PCLA is homologous to yeast Pcl cyclins, which interact with the Pho85 cyclin-dependent kinase. Although interaction with a PSTAIRE kinase was shown in vivo, PCLA function during sporulation was independent of theA. nidulans Pho85 homologue PHOA. Besides the developmental regulation, pclA expression was cell cycle dependent with peak transcript levels in S phase. Our findings suggest a role for PCLA in mediating cell cycle events during late stages of sporulation.

scholarly journals Developmental Activation of the Rb–E2F Pathway and Establishment of Cell Cycle-regulated Cyclin-dependent Kinase Activity during Embryonic Stem Cell Differentiation

2005 ◽  
Vol 16 (4) ◽  
pp. 2018-2027 ◽  
Author(s):  
Josephine White ◽  
Elaine Stead ◽  
Renate Faast ◽  
Simon Conn ◽  
Peter Cartwright ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Target Genes ◽  
Embryonic Stem ◽  
Stem Cell Differentiation ◽  
Embryonic Stem Cell Differentiation ◽  
Cyclin Dependent Kinase ◽  
Pluripotent Cells ◽  
Cyclin E1 ◽  
Cdk2 Activity ◽  
Cycle Dependent

To understand cell cycle control mechanisms in early development and how they change during differentiation, we used embryonic stem cells to model embryonic events. Our results demonstrate that as pluripotent cells differentiate, the length of G1 phase increases substantially. At the molecular level, this is associated with a significant change in the size of active cyclin-dependent kinase (Cdk) complexes, the establishment of cell cycle-regulated Cdk2 activity and the activation of a functional Rb–E2F pathway. The switch from constitutive to cell cycle-dependent Cdk2 activity coincides with temporal changes in cyclin A2 and E1 protein levels during the cell cycle. Transcriptional mechanisms underpin the down-regulation of cyclin levels and the establishment of their periodicity during differentiation. As pluripotent cells differentiate and pRb/p107 kinase activities become cell cycle dependent, the E2F–pRb pathway is activated and imposes cell cycle-regulated transcriptional control on E2F target genes, such as cyclin E1. These results suggest the existence of a feedback loop where Cdk2 controls its own activity through regulation of cyclin E1 transcription. Changes in rates of cell division, cell cycle structure and the establishment of cell cycle-regulated Cdk2 activity can therefore be explained by activation of the E2F–pRb pathway.

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