scholarly journals A divergent cyclin/cyclin-dependent kinase complex controls the atypical replication of a malaria parasite during gametogony and transmission

2020 ◽  
Author(s):  
Aurélia C Balestra ◽  
Mohammad Zeeshan ◽  
Edward Rea ◽  
Carla Pasquarello ◽  
Lorenzo Brusini ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Plasmodium Berghei ◽  
Functional Space ◽  
Eukaryotic Cell ◽  
Cyclin Dependent Kinase ◽  
Cyclin Dependent Kinases ◽  
Unique Cell ◽  
Atypical Mitosis ◽  
Replicative Cycle

SummaryCell cycle transitions are generally triggered by variation in the activity of cyclin-dependent kinases (CDKs) bound to cyclins. Malaria-causing parasites have a life cycle with unique cell-division cycles, and a repertoire of divergent CDKs and cyclins of poorly understood function and interdependency. We show that Plasmodium berghei CDK-related kinase 5 (CRK5), is a critical regulator of atypical mitosis in the gametogony and is required for mosquito transmission. It phosphorylates canonical CDK motifs of components in the pre-replicative complex and is essential for DNA replication. During a replicative cycle, CRK5 stably interacts with a single Plasmodium-specific cyclin (SOC2), although we obtained no evidence of SOC2 cycling by transcription, translation or degradation. Our results provide evidence that during Plasmodium male gametogony, this divergent cyclin/CDK pair fills the functional space of other eukaryotic cell-cycle kinases controlling DNA replication.

scholarly journals A divergent cyclin/cyclin-dependent kinase complex controls the atypical replication of a malaria parasite during gametogony and transmission

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Aurélia C Balestra ◽  
Mohammad Zeeshan ◽  
Edward Rea ◽  
Carla Pasquarello ◽  
Lorenzo Brusini ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Plasmodium Berghei ◽  
Functional Space ◽  
Eukaryotic Cell ◽  
Cyclin Dependent Kinase ◽  
Cyclin Dependent Kinases ◽  
Unique Cell ◽  
Atypical Mitosis ◽  
Replicative Cycle

Cell cycle transitions are generally triggered by variation in the activity of cyclin-dependent kinases (CDKs) bound to cyclins. Malaria-causing parasites have a life cycle with unique cell-division cycles, and a repertoire of divergent CDKs and cyclins of poorly understood function and interdependency. We show that Plasmodium berghei CDK-related kinase 5 (CRK5), is a critical regulator of atypical mitosis in the gametogony and is required for mosquito transmission. It phosphorylates canonical CDK motifs of components in the pre-replicative complex and is essential for DNA replication. During a replicative cycle, CRK5 stably interacts with a single Plasmodium-specific cyclin (SOC2), although we obtained no evidence of SOC2 cycling by transcription, translation or degradation. Our results provide evidence that during Plasmodium male gametogony, this divergent cyclin/CDK pair fills the functional space of other eukaryotic cell-cycle kinases controlling DNA replication.

Cyclin specificity: how many wheels do you need on a unicycle?

2001 ◽  
Vol 114 (10) ◽  
pp. 1811-1820 ◽  
Author(s):  
M.E. Miller ◽  
F.R. Cross
Keyword(s):  
Cell Cycle ◽  
Subcellular Localization ◽  
Cell Cycle Progression ◽  
Eukaryotic Cell ◽  
Cyclin Dependent Kinase ◽  
Temporal Expression ◽  
Cycle Progression

Cyclin-dependent kinase (CDK) activity is essential for eukaryotic cell cycle events. Multiple cyclins activate CDKs in all eukaryotes, but it is unclear whether multiple cyclins are really required for cell cycle progression. It has been argued that cyclins may predominantly act as simple enzymatic activators of CDKs; in opposition to this idea, it has been argued that cyclins might target the activated CDK to particular substrates or inhibitors. Such targeting might occur through a combination of factors, including temporal expression, protein associations, and subcellular localization.

scholarly journals The proteasome controls ESCRT-III–mediated cell division in an archaeon

Science ◽  
2020 ◽  
Vol 369 (6504) ◽  
pp. eaaz2532 ◽  
Author(s):  
Gabriel Tarrason Risa ◽  
Fredrik Hurtig ◽  
Sian Bray ◽  
Anne E. Hafner ◽  
Lena Harker-Kirschneck ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Dna Replication ◽  
Division Ring ◽  
Cell Cycle Control ◽  
Sulfolobus Acidocaldarius ◽  
Cyclin Dependent Kinase ◽  
Membrane Remodeling

Sulfolobus acidocaldarius is the closest experimentally tractable archaeal relative of eukaryotes and, despite lacking obvious cyclin-dependent kinase and cyclin homologs, has an ordered eukaryote-like cell cycle with distinct phases of DNA replication and division. Here, in exploring the mechanism of cell division in S. acidocaldarius, we identify a role for the archaeal proteasome in regulating the transition from the end of one cell cycle to the beginning of the next. Further, we identify the archaeal ESCRT-III homolog, CdvB, as a key target of the proteasome and show that its degradation triggers division by allowing constriction of the CdvB1:CdvB2 ESCRT-III division ring. These findings offer a minimal mechanism for ESCRT-III–mediated membrane remodeling and point to a conserved role for the proteasome in eukaryotic and archaeal cell cycle control.

scholarly journals Structure-function relationships of the yeast cyclin-dependent kinase Pho85.

1995 ◽  
Vol 15 (10) ◽  
pp. 5482-5491 ◽  
Author(s):  
R C Santos ◽  
N C Waters ◽  
C L Creasy ◽  
L W Bergman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Structure Function ◽  
Cell Cycle Progression ◽  
Substrate Recognition ◽  
The Other ◽  
Cyclin Dependent Kinase ◽  
Cycle Progression ◽  
Cyclin Dependent Kinases ◽  
Induced Mutagenesis

The PHO85 gene of Saccharomyces cerevisiae encodes a cyclin-dependent kinase involved in both transcriptional regulation and cell cycle progression. Although a great deal is known concerning the structure, function, and regulation of the highly homologous Cdc28 protein kinase, little is known concerning these relationships in regard to Pho85. In this study, we constructed a series of Pho85-Cdc28 chimeras to map the region(s) of the Pho85 molecule that is critical for function of Pho85 in repression of acid phosphatase (PHO5) expression. Using a combination of site-directed and ethyl methanesulfonate-induced mutagenesis, we have identified numerous residues critical for either activation of the Pho85 kinase, interaction of Pho85 with the cyclin-like molecule Pho80, or substrate recognition. Finally, analysis of mutations analogous to those previously identified in either Cdc28 or cdc2 of Schizosaccharomyces pombe suggested that the inhibition of Pho85-Pho80 activity in mechanistically different from that seen in the other cyclin-dependent kinases.

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 A quantitative model for cyclin-dependent kinase control of the cell cycle: revisited

2011 ◽  
Vol 366 (1584) ◽  
pp. 3572-3583 ◽  
Author(s):  
Frank Uhlmann ◽  
Céline Bouchoux ◽  
Sandra López-Avilés
Keyword(s):  
Cell Cycle ◽  
Eukaryotic Cell ◽  
Quantitative Model ◽  
S Phase ◽  
Cyclin Dependent Kinase ◽  
Genomic Integrity ◽  
Chromosomal Dna ◽  
Substrate Specificities ◽  
Daughter Cells ◽  
Molecular Events

The eukaryotic cell division cycle encompasses an ordered series of events. Chromosomal DNA is replicated during S phase of the cell cycle before being distributed to daughter cells in mitosis. Both S phase and mitosis in turn consist of an intricately ordered sequence of molecular events. How cell cycle ordering is achieved, to promote healthy cell proliferation and avert insults on genomic integrity, has been a theme of Paul Nurse's research. To explain a key aspect of cell cycle ordering, sequential S phase and mitosis, Stern & Nurse proposed ‘A quantitative model for cdc2 control of S phase and mitosis in fission yeast’. In this model, S phase and mitosis are ordered by their dependence on increasing levels of cyclin-dependent kinase (Cdk) activity. Alternative mechanisms for ordering have been proposed that rely on checkpoint controls or on sequential waves of cyclins with distinct substrate specificities. Here, we review these ideas in the light of experimental evidence that has meanwhile accumulated. Quantitative Cdk control emerges as the basis for cell cycle ordering, fine-tuned by cyclin specificity and checkpoints. We propose a molecular explanation for quantitative Cdk control, based on thresholds imposed by Cdk-counteracting phosphatases, and discuss its implications.

Genetic control of mitosis, meiosis and cellular differentiation during mammalian spermatogenesis

1995 ◽  
Vol 7 (4) ◽  
pp. 669 ◽  
Author(s):  
DJ Wolgemuth ◽  
K Rhee ◽  
S Wu ◽  
SE Ravnik
Keyword(s):  
Cell Cycle ◽  
Genetic Control ◽  
Current Knowledge ◽  
Cell Cycle Control ◽  
Mitotic Cell ◽  
Eukaryotic Cell ◽  
Model Systems ◽  
Regulatory Processes ◽  
Mammalian Cell Lines ◽  
Unique Cell

Gametogenesis in both the male and female mammal represents a specialized and highly regulated series of cell cycle events, involving both mitosis and meiosis as well as subsequent differentiation. Recent advances in our understanding of the genetic control of the eukaryotic cell cycle have underscored the evolutionarily-conserved nature of these regulatory processes. However, most of the data have been obtained from yeast model systems and mammalian cell lines. Furthermore, most of the observations focus on regulation of mitotic cell cycles. In the present paper: (i) aspects of gametogenesis in mammals that represent unique cell-cycle control points are highlighted; (ii) current knowledge on the regulation of the germ cell cycle, in the context of what is known in yeast and other model eukaryotic systems, is summarized; and (iii) strategies that can be used to identify additional cell cycle regulating genes are outlined.

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 p27Kip1 induces an accumulation of the repressor complexes of E2F and inhibits expression of the E2F-regulated genes.

1997 ◽  
Vol 8 (9) ◽  
pp. 1815-1827 ◽  
Author(s):  
P Shiyanov ◽  
S Hayes ◽  
N Chen ◽  
D G Pestov ◽  
L F Lau ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Binding Sites ◽  
Culture Medium ◽  
Cyclin E ◽  
Cyclin A ◽  
Cyclin Dependent Kinase ◽  
Binding Motifs ◽  
Cyclin Dependent Kinases ◽  
Cell Cycle Inhibition ◽  
A Cell

p27Kip1 is an inhibitor of the cyclin-dependent kinases and it plays an inhibitory role in the progression of cell cycle through G1 phase. To investigate the mechanism of cell cycle inhibition by p27Kip1, we constructed a cell line that inducibly expresses p27Kip1 upon addition of isopropyl-1-thio-beta-D-galactopyranoside in the culture medium. Isopropyl-1-thio-beta-D-galactopyranoside-induced expression of p27Kip1 in these cells causes a specific reduction in the expression of the E2F-regulated genes such as cyclin E, cyclin A, and dihydrofolate reductase. The reduction in the expression of these genes correlates with the p27Kip1-induced accumulation of the repressor complexes of the E2F family of factors (E2Fs). Our previous studies indicated that p21WAF1 could disrupt the interaction between cyclin/cyclin-dependent kinase 2 (cdk2) and the E2F repressor complexes E2F-p130 and E2F-p107. We show that p27Kip1, like p21WAF1, disrupts cyclin/cdk2-containing complexes of E2F-p130 leading to the accumulation of the E2F-p130 complexes, which is found in growth-arrested cells. In transient transfection assays, expression of p27Kip1 specifically inhibits transcription of a promoter containing E2F-binding sites. Mutants of p27Kip1 harboring changes in the cyclin- and cdk2-binding motifs are deficient in inhibiting transcription from the E2F sites containing reporter gene. Moreover, these mutants of p27Kip1 are also impaired in disrupting the interaction between cyclin/cdk2 and the repressor complexes of E2Fs. Taken together, these observations suggest that p27Kip1 reduces expression of the E2F-regulated genes by generating repressor complexes of E2Fs. Furthermore, the results also demonstrate that p27Kip1 inhibits expression of cyclin A and cyclin E, which are critical for progression through the G1-S phases.

scholarly journals CDK2 activity determines the timing of cell-cycle commitment and sequential DNA replication

2020 ◽  
Author(s):  
Sungsoo Kim ◽  
Alessandra Leong ◽  
Chellam Nayar ◽  
Minah Kim ◽  
Hee Won Yang
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Mammalian Cells ◽  
Genome Stability ◽  
Threshold Level ◽  
Cyclin Dependent Kinases ◽  
Safety Mechanism ◽  
Cdk2 Activity ◽  
Tightly Coupled ◽  
Rb Phosphorylation

AbstractTo enter the cell cycle, mammalian cells must cross a point of no return (the commitment point), after which they proceed through the cell cycle regardless of changes in external signaling. This process is tightly regulated by the cyclin-dependent kinases (CDKs) and downstream molecules such as retinoblastoma (Rb). Here we show that CDK2 activity coordinates the timing of cell-cycle commitment and DNA replication. CDK4/6 activation initiates Rb phosphorylation and E2F activity, causing a gradual increase in CDK2 activity. Once CDK2 activity reaches a threshold level, CDK2 triggers the commitment point by maintaining Rb phosphorylation and subsequently initiates DNA replication. While the timing of the commitment point is tightly coupled with DNA replication, our experiments, which acutely increased CDK2 activity, suggest that the timing of the commitment point is before DNA replication. These findings highlight how cells utilize a safety mechanism to maintain genome stability by protecting against incomplete DNA replication.

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