The <i>Giardia</i> cell cycle progresses independently of the Anaphase Promoting Complex

Gourguechon, Stéphane; Holt, Liam J.; Cande, W. Zacheus

doi:10.1242/jcs.121632

Cited by 53 publications

(60 citation statements)

References 44 publications

(59 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although almost all eukaryotic genomes contain clear sequence homologs for APC components, Giardia intestinalis has none, and cyclin B degradation may occur by entirely different mechanisms (Gourguechon et al 2013). This led to the suggestion that the ancestral eukaryote might have lacked the APC, a conclusion that depends on the deepest rooting of the eukaryotic tree.…”

Section: Results)mentioning

confidence: 99%

Interregulation of CDKA/CDK1 and the Plant-Specific Cyclin-Dependent Kinase CDKB in Control of the Chlamydomonas Cell Cycle

Atkins

Cross

2018

Plant Cell

View full text Add to dashboard Cite

Short title: CDK regulation of the Chlamydomonas cell cycleOne-sentence summary: Chlamydomonas CDKA and CYCA1 are dispensable for mitosis, but the plant-specific CDKB, probably in complex with CYCB1, promotes most events of mitosis and downregulates CDKA following cell division.The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantcell.org) is: Frederick R. Cross (fcross@mail.rockefeller.edu). ABSTRACTThe cyclin-dependent kinase CDK1 is essential for mitosis in fungi and animals. Plant genomes contain the CDK1 ortholog CDKA, and a plant kingdom-specific relative, CDKB. The green alga Chlamydomonas reinhardtii has a long G1 growth period followed by rapid cycles of DNA replication and cell division. We show that null alleles of CDKA extend the growth period prior to the first division cycle and modestly extend the subsequent division cycles, but do not prevent cell division, indicating at most a minor role for the CDK1 ortholog in mitosis in Chlamydomonas. A null allele of cyclin A has a similar though less extreme phenotype. In contrast, both CDKB and cyclin B are essential for mitosis. CDK kinase activity measurements imply that the predominant in vivo complexes are probably cyclin A-CDKA and cyclin B-CDKB. We propose a negative feedback loop: CDKA activates cyclin B-CDKB. Cyclin B-CDKB in turn promotes mitotic entry and inactivates cyclin A-CDKA. Cyclin A-CDKA and cyclin B-CDKB may redundantly promote DNA replication. We show that the anaphase-promoting complex is required for inactivation of both CDKA and CDKB and is essential for anaphase. These results are consistent with findings in Arabidopsis and may delineate the core of plant kingdom cell cycle control which, compared to the well-studied yeast and animal systems, exhibits deep conservation in some respects and striking divergence in others.

show abstract

Section: Results)mentioning

confidence: 99%

Interregulation of CDKA/CDK1 and the Plant-Specific Cyclin-Dependent Kinase CDKB in Control of the Chlamydomonas Cell Cycle

Atkins

Cross

2018

Plant Cell

View full text Add to dashboard Cite

show abstract

“…This suggests that key mitotic regulators might be regulated by other mechanisms. In addition, several studies suggest that both Cdc20 and Cdh1 have functions independent of APC/C (Clarke et al, 2003; Goh et al, 2000; Gourguechon et al, 2013; Pfleger et al, 2001; Thornton and Toczyski, 2003). …”

Section: Introductionmentioning

confidence: 99%

Parkin Regulates Mitosis and Genomic Stability through Cdc20/Cdh1

et al. 2015

View full text Add to dashboard Cite

SUMMARY Mutations in the E3 ubiquitin ligase Parkin have been linked to familial Parkinson's disease. Parkin has also been implicated in mitosis through mechanisms that are unclear. Here we show that Parkin interacts with anaphase promoting complex/cyclosome (APC/C) co-activators Cdc20 and Cdh1 to mediate the degradation of several key mitotic regulators independent of APC/C. We demonstrate that ordered progression through mitosis is orchestrated by two distinct E3 ligases through the shared use of Cdc20 and Cdh1. Furthermore, Parkin is phosphorylated and activated by polo-like kinase 1 (Plk1) during mitosis. Parkin deficiency results in overexpression of its substrates, mitotic defects, genomic instability and tumorigenesis. These results suggest that the Parkin-Cdc20/Cdh1 complex is an important regulator of mitosis.

show abstract

“…Interestingly, however, even though the idea that the four lineages originally proposed to be Archezoa is scientifically dead, it does continue to have a notable effect on our thinking about those lineages. They have, in general, and the diplomonad Giardia, in particular, maintained a stubborn reputation as being ancient or primitive eukaryotes (Morrison et al 2007;Gourguechon et al 2013). This is no longer specifically tied to their lack of mitochondria, but it is doubtful that this perception would have gained such popularity without the Archezoa hypothesis.…”

Section: Historical Views Of the Origin Of Eukaryotesmentioning

confidence: 99%

The Impact of History on Our Perception of Evolutionary Events: Endosymbiosis and the Origin of Eukaryotic Complexity

Keeling

2014

Cold Spring Harbor Perspectives in Biology

View full text Add to dashboard Cite

Evolutionary hypotheses are correctly interpreted as products of the data they set out to explain, but they are less often recognized as being heavily influenced by other factors. One of these is the history of preceding thought, and here I look back on historically important changes in our thinking about the role of endosymbiosis in the origin of eukaryotic cells. Specifically, the modern emphasis on endosymbiotic explanations for numerous eukaryotic features, including the cell itself (the so-called chimeric hypotheses), can be seen not only as resulting from the advent of molecular and genomic data, but also from the intellectual acceptance of the endosymbiotic origin of mitochondria and plastids. This transformative idea may have unduly affected how other aspects of the eukaryotic cell are explained, in effect priming us to accept endosymbiotic explanations for endogenous processes. Molecular and genomic data, which were originally harnessed to answer questions about cell evolution, now so dominate our thinking that they largely define the question, and the original questions about how eukaryotic cellular architecture evolved have been neglected. This is unfortunate because, as Roger Stanier pointed out, these cellular changes represent life's "greatest single evolutionary discontinuity," and on this basis I advocate a return to emphasizing evolutionary cell biology when thinking about the origin of eukaryotes, and suggest that endogenous explanations will prevail when we refocus on the evolution of the cell.T he origin and early diversification of eukaryotes are topics that invite big stories because the changes that took place were big ones. The origin of eukaryotes was the biggest change in cell biology since the Last Universal Common Ancestor (LUCA) of all known life-nearly every major aspect of eukaryotic cells is different in some way from the corresponding characters found in bacteria and archaeans, some profoundly so. Not only are they different at the cellular level in possessing a nucleus and endomembrane system, cytoskeleton, and semiautonomous membrane-bounded organelles (mitochondria and sometimes plastids), for example, but they also possess different means of replicating and expressing genetic information. Moreover, the differences between eukaryotes and other cellular life only increase as you look more closely. At the gross level, eukaryotic genes are organized differently than prokaryotic ones, but the initiation, elongation, and termination of transcription and translation are also different, and even the factors involved in core components of these events are often different. Of course, many aspects of archaeal molecular biology have been found to be shared with eukaryotes (Ouzonis and Sander 1992;Creti et al. 1993;Langer and Zillig 1993;Zillig et al. 1993; Keeling and Doolittle 1995a,b). Notwithstanding these similarities, much about eukaryotes remains unique, and in need of explanation. Unfortunately for evolutionary biologists, this transition has left behind few intermediates (other ...

show abstract

The Giardia cell cycle progresses independently of the Anaphase Promoting Complex

Cited by 53 publications

References 44 publications

Interregulation of CDKA/CDK1 and the Plant-Specific Cyclin-Dependent Kinase CDKB in Control of the Chlamydomonas Cell Cycle

Interregulation of CDKA/CDK1 and the Plant-Specific Cyclin-Dependent Kinase CDKB in Control of the Chlamydomonas Cell Cycle

Parkin Regulates Mitosis and Genomic Stability through Cdc20/Cdh1

The Impact of History on Our Perception of Evolutionary Events: Endosymbiosis and the Origin of Eukaryotic Complexity

Contact Info

Product

Resources

About