Archaeal DNA Replication

It is now well recognized that the information processing machineries of archaea are far more closely related to those of eukaryotes than to those of their prokaryotic cousins, the bacteria. Extensive studies have been performed on the structure and function of the archaeal DNA replication origins, the proteins that define them, and the macromolecular assemblies that drive DNA unwinding and nascent strand synthesis. The results from various archaeal organisms across the archaeal domain of life show surprising levels of diversity at many levels—ranging from cell cycle organization to chromosome ploidy to replication mode and nature of the replicative polymerases. In the following, we describe recent advances in the field, highlighting conserved features and lineage-specific innovations.

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Drosophila dCBP Is Involved in Establishing the DNA Replication Checkpoint

Molecular and Cellular Biology ◽

10.1128/mcb.01283-06 ◽

2006 ◽

Vol 27 (1) ◽

pp. 135-146 ◽

Cited By ~ 15

Author(s):

Sarah Smolik ◽

Kristen Jones

Keyword(s):

Cell Cycle ◽

Dna Replication ◽

Cell Cycle Arrest ◽

Chromatin Structure ◽

Genetic Interaction ◽

Structure And Function ◽

Replication Checkpoint ◽

Cycle Arrest ◽

Dna Replication Checkpoint ◽

And Function

ABSTRACT The CBP/p300 family of proteins comprises related acetyltransferases that coactivate signal-responsive transcription. Recent evidence suggests that p300/CBP may also interact directly with complexes that mediate different aspects of DNA metabolism such as replication and repair. In this report, we show that loss of dCBP in Drosophila cells and eye discs results in a defect in the cell cycle arrest induced by stalled DNA replication. We show that dCBP and the checkpoint kinase Mei-41 can be found together in a complex and, furthermore, that dCBP has a genetic interaction with mei-41 in the response to stalled DNA replication. These observations suggest a broader role for the p300/CBP acetyltransferases in the modulation of chromatin structure and function during DNA metabolic events as well as for transcription.

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Cdc6p establishes and maintains a state of replication competence during G1 phase

Journal of Cell Science ◽

10.1242/jcs.110.6.753 ◽

1997 ◽

Vol 110 (6) ◽

pp. 753-763 ◽

Cited By ~ 1

Author(s):

C.S. Detweiler ◽

J.J. Li

Keyword(s):

Cell Cycle ◽

Dna Replication ◽

Transcriptional Repression ◽

Prolonged Exposure ◽

S Phase ◽

Restrictive Temperature ◽

Yeast Saccharomyces Cerevisiae ◽

Important Intermediate ◽

Initiation Of Dna Replication ◽

And Function

CDC6 is essential for the initiation of DNA replication in the budding yeast Saccharomyces cerevisiae. Here we examine the timing of Cdc6p expression and function during the cell cycle. Cdc6p is expressed primarily between mitosis and Start. This pattern of expression is due in part to posttranscriptional controls, since it is maintained when CDC6 is driven by a constitutively induced promoter. Transcriptional repression of CDC6 or exposure of cdc6-1(ts) cells to the restrictive temperature at mitosis blocks subsequent S phase, demonstrating that the activity of newly synthesized Cdc6p is required each cell cycle for DNA replication. In contrast, similar perturbations imposed on cells arrested in G(1) before Start have moderate or no effects on DNA replication. This suggests that, between mitosis and Start, Cdc6p functions in an early step of initiation, effectively making cells competent for replication. Prolonged exposure of cdc6-1(ts) cells to the restrictive temperature at the pre-Start arrest eventually does cripple S phase, indicating that Cdc6p also functions to maintain this initiation competence during G(1). The requirement for Cdc6p to establish and maintain initiation competence tightly correlates with the requirement for Cdc6p to establish and maintain the pre-replicative complex at a replication origin, strongly suggesting that the pre-replicative complex is an important intermediate for the initiation of DNA replication. Confining assembly of the complex to G(1) by restricting expression of Cdc6p to this period may be one way of ensuring precisely one round of replication per cell cycle.

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The structure and function of centriolar rootlets

Journal of Cell Science ◽

10.1242/jcs.258544 ◽

2021 ◽

Vol 134 (16) ◽

Author(s):

Robert Mahen

Keyword(s):

Cellular Function ◽

Structure And Function ◽

Cellular Systems ◽

Macromolecular Assemblies ◽

Cellular Processes ◽

Holistic Understanding ◽

Eukaryotic Organisms ◽

And Function ◽

Knockout Animals

ABSTRACT To gain a holistic understanding of cellular function, we must understand not just the role of individual organelles, but also how multiple macromolecular assemblies function collectively. Centrioles produce fundamental cellular processes through their ability to organise cytoskeletal fibres. In addition to nucleating microtubules, centrioles form lesser-known polymers, termed rootlets. Rootlets were identified over a 100 years ago and have been documented morphologically since by electron microscopy in different eukaryotic organisms. Rootlet-knockout animals have been created in various systems, providing insight into their physiological functions. However, the precise structure and function of rootlets is still enigmatic. Here, I consider common themes of rootlet function and assembly across diverse cellular systems. I suggest that the capability of rootlets to form physical links from centrioles to other cellular structures is a general principle unifying their functions in diverse cells and serves as an example of how cellular function arises from collective organellar activity.

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