scholarly journals Phosphoregulation of Rad51/Rad52 by CDK1 functions as a molecular switch for cell cycle–specific activation of homologous recombination

2020 ◽  
Vol 6 (6) ◽  
pp. eaay2669 ◽  
Author(s):  
Gyubum Lim ◽  
Yeonji Chang ◽  
Won-Ki Huh
Keyword(s):  
Cell Cycle ◽  
Homologous Recombination ◽  
Kinase Activity ◽  
Regulatory Mechanism ◽  
Specific Cell ◽  
Cyclin Dependent Kinase ◽  
Recombination Activity ◽  
M Phase ◽  
Dna Binding Affinity ◽  
Cycle Dependent

Homologous recombination is exquisitely activated only during specific cell phases. In the G1 phase, homologous recombination activity is completely suppressed. According to previous reports, the activation of homologous recombination during specific cell phases depends on the kinase activity of cyclin-dependent kinase 1 (CDK1). However, the precise regulatory mechanism and target substrates of CDK1 for this regulation have not been completely determined. Here, we report that the budding yeast CDK1, Cdc28, phosphorylates the major homologous recombination regulators Rad51 and Rad52. This phosphorylation occurs in the G2/M phase by Cdc28 in combination with G2/M phase cyclins. Nonphosphorylatable mutations in Rad51 and Rad52 impair the DNA binding affinity of Rad51 and the affinity between Rad52 rings that leads to their interaction. Collectively, our data provide detailed insights into the regulatory mechanism of cell cycle–dependent homologous recombination activation in eukaryotic cells.

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 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 Cell Cycle-Dependent Expression of Mammalian E2-C Regulated by the Anaphase-Promoting Complex/Cyclosome

2000 ◽  
Vol 11 (8) ◽  
pp. 2821-2831 ◽  
Author(s):  
Atsushi Yamanaka ◽  
Shigetsugu Hatakeyama ◽  
Kin-ichiro Kominami ◽  
Masatoshi Kitagawa ◽  
Masaki Matsumoto ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Substrate Specificity ◽  
Critical Role ◽  
Anaphase Promoting Complex ◽  
Polyubiquitin Chain ◽  
M Phase ◽  
Ubiquitin Conjugating Enzyme ◽  
Recognition Motifs ◽  
Cycle Dependent ◽  
Conjugating Enzyme

Progression through mitosis requires the precisely timed ubiquitin-dependent degradation of specific substrates. E2-C is a ubiquitin-conjugating enzyme that plays a critical role with anaphase-promoting complex/cyclosome (APC/C) in progression of and exit from M phase. Here we report that mammalian E2-C is expressed in late G2/M phase and is degraded as cells exit from M phase. The mammalian E2-C shows an autoubiquitinating activity leading to covalent conjugation to itself with several ubiquitins. The ubiquitination of E2-C is strongly enhanced by APC/C, resulting in the formation of a polyubiquitin chain. The polyubiquitination of mammalian E2-C occurs only when cells exit from M phase. Furthermore, mammalian E2-C contains two putative destruction boxes that are believed to act as recognition motifs for APC/C. The mutation of this motif reduced the polyubiquitination of mammalian E2-C, resulting in its stabilization. These results suggest that mammalian E2-C is itself a substrate of the APC/C-dependent proteolysis machinery, and that the periodic expression of mammalian E2-C may be a novel autoregulatory system for the control of the APC/C activity and its substrate specificity.

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.

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 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 Coupling Phosphate Homeostasis to Cell Cycle-Specific Transcription: Mitotic Activation of Saccharomyces cerevisiae PHO5 by Mcm1 and Forkhead Proteins

2009 ◽  
Vol 29 (18) ◽  
pp. 4891-4905 ◽  
Author(s):  
Santhi Pondugula ◽  
Daniel W. Neef ◽  
Warren P. Voth ◽  
Russell P. Darst ◽  
Archana Dhasarathy ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Mitotic Cell ◽  
Dependent Manner ◽  
Phosphate Homeostasis ◽  
Periodic Cell ◽  
M Phase ◽  
Cycle Dependent ◽  
Nutrient Homeostasis

ABSTRACT Cells devote considerable resources to nutrient homeostasis, involving nutrient surveillance, acquisition, and storage at physiologically relevant concentrations. Many Saccharomyces cerevisiae transcripts coding for proteins with nutrient uptake functions exhibit peak periodic accumulation during M phase, indicating that an important aspect of nutrient homeostasis involves transcriptional regulation. Inorganic phosphate is a central macronutrient that we have previously shown oscillates inversely with mitotic activation of PHO5. The mechanism of this periodic cell cycle expression remains unknown. To date, only two sequence-specific activators, Pho4 and Pho2, were known to induce PHO5 transcription. We provide here evidence that Mcm1, a MADS-box protein, is essential for PHO5 mitotic activation. In addition, we found that cells simultaneously lacking the forkhead proteins, Fkh1 and Fkh2, exhibited a 2.5-fold decrease in PHO5 expression. The Mcm1-Fkh2 complex, first shown to transactivate genes within the CLB2 cluster that drive G2/M progression, also associated directly at the PHO5 promoter in a cell cycle-dependent manner in chromatin immunoprecipitation assays. Sds3, a component specific to the Rpd3L histone deacetylase complex, was also recruited to PHO5 in G1. These findings provide (i) further mechanistic insight into PHO5 mitotic activation, (ii) demonstrate that Mcm1-Fkh2 can function combinatorially with other activators to yield late M/G1 induction, and (iii) couple the mitotic cell cycle progression machinery to cellular phosphate homeostasis.

Posttranscriptional cell cycle–dependent regulation of human FANCC expression

Blood ◽  
2000 ◽  
Vol 95 (12) ◽  
pp. 3970-3977 ◽  
Author(s):  
Michael C. Heinrich ◽  
Kirsten V. Silvey ◽  
Stacie Stone ◽  
Amy J. Zigler ◽  
Diana J. Griffith ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dynamic Control ◽  
Complementation Group ◽  
Molecular Regulation ◽  
Phase Cell ◽  
Physical Interaction ◽  
Dependent Manner ◽  
M Phase ◽  
Intensive Investigation ◽  
Cycle Dependent

The Fanconi Anemia (FA) Group C complementation group gene (FANCC) encodes a protein, FANCC, with a predicted Mr of 63000 daltons. FANCC is found in both the cytoplasmic and the nuclear compartments and interacts with certain other FA complementation group proteins as well as with non-FA proteins. Despite intensive investigation, the biologic roles of FANCC and of the other cloned FA gene products (FANCA and FANCG) remain unknown. As an approach to understanding FANCC function, we have studied the molecular regulation of FANCC expression. We found that although FANCCmRNA levels are constant throughout the cell cycle, FANCC is expressed in a cell cycle-dependent manner, with the lowest levels seen in cells synchronized at the G1/S boundary and the highest levels in the M-phase. Cell cycle–dependent regulation occurred despite deletion of the 5′ and 3′ FANCC untranslated regions, indicating that information in the FANCC coding sequence is sufficient to mediate cell cycle–dependent regulation. Moreover, inhibitors of proteasome function blocked the observed regulation. We conclude that FANCC expression is controlled by posttranscriptional mechanisms that are proteasome dependent. Recent work has demonstrated that the functional activity of FA proteins requires the physical interaction of at least FANCA, FANCC, and FANCG, and possibly of other FA and non-FA proteins. Our observation of dynamic control of FANCC expression by the proteasome has important implications for understanding the molecular regulation of the multiprotein complex.

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.

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