scholarly journals A Mutation in DNA Polymerase α Rescues WEE1KO Sensitivity to HU

2021 ◽  
Vol 22 (17) ◽  
pp. 9409
Author(s):  
Thomas Eekhout ◽  
José Antonio Pedroza-Garcia ◽  
Pooneh Kalhorzadeh ◽  
Geert De Jaeger ◽  
Lieven De Veylder
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Dna Polymerase ◽  
Driving Force ◽  
S Phase ◽  
Catalytic Subunit ◽  
Genomic Integrity ◽  
Cyclin Dependent Kinases ◽  
Dna Polymerase Α ◽  
Wee1 Kinase

During DNA replication, the WEE1 kinase is responsible for safeguarding genomic integrity by phosphorylating and thus inhibiting cyclin-dependent kinases (CDKs), which are the driving force of the cell cycle. Consequentially, wee1 mutant plants fail to respond properly to problems arising during DNA replication and are hypersensitive to replication stress. Here, we report the identification of the polα-2 mutant, mutated in the catalytic subunit of DNA polymerase α, as a suppressor mutant of wee1. The mutated protein appears to be less stable, causing a loss of interaction with its subunits and resulting in a prolonged S-phase.

scholarly journals A Coordinated Temporal Interplay of Nucleosome Reorganization Factor, Sister Chromatin Cohesion Factor, and DNA Polymerase α Facilitates DNA Replication

2004 ◽  
Vol 24 (21) ◽  
pp. 9568-9579 ◽  
Author(s):  
Yanjiao Zhou ◽  
Teresa S.-F. Wang
Keyword(s):  
Dna Replication ◽  
Dna Polymerase ◽  
S Phase ◽  
Terminal Region ◽  
Replication Complex ◽  
Dna Polymerase Α ◽  
Chromatid Cohesion ◽  
Phase Progression

ABSTRACT DNA replication depends critically upon chromatin structure. Little is known about how the replication complex overcomes the nucleosome packages in chromatin during DNA replication. To address this question, we investigate factors that interact in vivo with the principal initiation DNA polymerase, DNA polymerase α (Polα). The catalytic subunit of budding yeast Polα (Pol1p) has been shown to associate in vitro with the Spt16p-Pob3p complex, a component of the nucleosome reorganization system required for both replication and transcription, and with a sister chromatid cohesion factor, Ctf4p. Here, we show that an N-terminal region of Polα (Pol1p) that is evolutionarily conserved among different species interacts with Spt16p-Pob3p and Ctf4p in vivo. A mutation in a glycine residue in this N-terminal region of POL1 compromises the ability of Pol1p to associate with Spt16p and alters the temporal ordered association of Ctf4p with Pol1p. The compromised association between the chromatin-reorganizing factor Spt16p and the initiating DNA polymerase Pol1p delays the Pol1p assembling onto and disassembling from the late-replicating origins and causes a slowdown of S-phase progression. Our results thus suggest that a coordinated temporal and spatial interplay between the conserved N-terminal region of the Polα protein and factors that are involved in reorganization of nucleosomes and promoting establishment of sister chromatin cohesion is required to facilitate S-phase progression.

scholarly journals Molecular cloning of the cDNA for the catalytic subunit of plant DNA polymerase α and its cell-cycle dependent expression

1997 ◽  
Vol 2 (11) ◽  
pp. 695-709 ◽  
Author(s):  
Masayuki Yokoi ◽  
Masaki Ito ◽  
Masako Izumi ◽  
Hiroshi Miyazawa ◽  
Hirokazu Nakai ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Molecular Cloning ◽  
Dna Polymerase ◽  
Catalytic Subunit ◽  
Dna Polymerase Α ◽  
Plant Dna ◽  
Cycle Dependent

scholarly journals Cell cycle-dependent phosphorylation and dephosphorylation of the yeast DNA polymerase alpha-primase B subunit.

1995 ◽  
Vol 15 (2) ◽  
pp. 883-891 ◽  
Author(s):  
M Foiani ◽  
G Liberi ◽  
G Lucchini ◽  
P Plevani
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Dna Polymerase ◽  
Posttranslational Modifications ◽  
S Phase ◽  
Dna Polymerase Alpha ◽  
B Subunit ◽  
Initiation Of Dna Replication ◽  
Cycle Dependent

The yeast DNA polymerase alpha-primase B subunit functions in initiation of DNA replication. This protein is present in two forms, of 86 and 91 kDa, and the p91 polypeptide results from cell cycle-regulated phosphorylation of p86. The B subunit present in G1 arises by dephosphorylation of p91 while cells are exiting from mitosis, becomes phosphorylated in early S phase, and is competent and sufficient to initiate DNA replication. The B subunit transiently synthesized as a consequence of periodic transcription of the POL12 gene is phosphorylated no earlier than G2. Phosphorylation of the B subunit does not require execution of the CDC7-dependent step and ongoing DNA synthesis. We suggest that posttranslational modifications of the B subunit might modulate the role of DNA polymerase alpha-primase in DNA replication.

scholarly journals Ubc4 and Not4 Regulate Steady-State Levels of DNA Polymerase-α to Promote Efficient and Accurate DNA Replication

2010 ◽  
Vol 21 (18) ◽  
pp. 3205-3219 ◽  
Author(s):  
Justin Haworth ◽  
Robert C. Alver ◽  
Melissa Anderson ◽  
Anja-Katrin Bielinsky
Keyword(s):  
Dna Replication ◽  
Dna Polymerase ◽  
Point Of View ◽  
Catalytic Subunit ◽  
Chromosomal Dna ◽  
Minichromosome Maintenance ◽  
Dna Polymerase Α ◽  
Steady State Levels ◽  
The Stability ◽  
The Right

The accurate duplication of chromosomal DNA is required to maintain genomic integrity. However, from an evolutionary point of view, a low mutation rate during DNA replication is desirable. One way to strike the right balance between accuracy and limited mutagenesis is to use a DNA polymerase that lacks proofreading activity but contributes to DNA replication in a very restricted manner. DNA polymerase-α fits this purpose exactly, but little is known about its regulation at the replication fork. Minichromosome maintenance protein (Mcm) 10 regulates the stability of the catalytic subunit of pol-α in budding yeast and human cells. Cdc17, the catalytic subunit of pol-α in yeast, is rapidly degraded after depletion of Mcm10. Here we show that Ubc4 and Not4 are required for Cdc17 destabilization. Disruption of Cdc17 turnover resulted in sensitivity to hydroxyurea, suggesting that this pathway is important for DNA replication. Furthermore, overexpression of Cdc17 in ubc4 and not4 mutants caused slow growth and synthetic dosage lethality, respectively. Our data suggest that Cdc17 levels are very tightly regulated through the opposing forces of Ubc4 and Not4 (destabilization) and Mcm10 (stabilization). We conclude that regular turnover of Cdc17 via Ubc4 and Not4 is required for proper cell proliferation.

DNA polymerase α in the fission yeast Schizosaccharomyces pombe: Identification and tracing of the catalytic subunit during the cell cycle

1992 ◽  
Vol 198 (2) ◽  
pp. 183-190 ◽  
Author(s):  
Dominique Bouvier ◽  
Georges Pignede ◽  
Veronique Damagnez ◽  
Jeanne Tillit ◽  
Anne-Marie de Recondo ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Dna Polymerase ◽  
Catalytic Subunit ◽  
Dna Polymerase Α

scholarly journals Novel Role for Cdc14 Sequestration: Cdc14 Dephosphorylates Factors That Promote DNA Replication

2006 ◽  
Vol 27 (3) ◽  
pp. 842-853 ◽  
Author(s):  
Joanna Bloom ◽  
Frederick R. Cross
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Dna Polymerase ◽  
Budding Yeast ◽  
S Phase ◽  
Mitotic Exit ◽  
Checkpoint Protein ◽  
Replication Factors ◽  
Established Role

ABSTRACT The phosphatase Cdc14 is required for mitotic exit in budding yeast. Cdc14 promotes Cdk1 inactivation by targeting proteins that, when dephosphorylated, trigger degradation of mitotic cyclins and accumulation of the Cdk1 inhibitor, Sic1. Cdc14 is sequestered in the nucleolus during most of the cell cycle but is released into the nucleus and cytoplasm during anaphase. When Cdc14 is not properly sequestered in the nucleolus, expression of the S-phase cyclin Clb5 is required for viability, suggesting that the antagonizing activity of Clb5-dependent Cdk1 specifically is necessary when Cdc14 is delocalized. We show that delocalization of Cdc14 combined with loss of Clb5 causes defects in DNA replication. When Cdc14 is not sequestered, it efficiently dephosphorylates a subset of Cdk1 substrates including the replication factors, Sld2 and Dpb2. Mutations causing Cdc14 mislocalization interact genetically with mutations affecting the function of DNA polymerase ε and the S-phase checkpoint protein Mec1. Our findings suggest that Cdc14 is retained in the nucleolus to support a favorable kinase/phosphatase balance while cells are replicating their DNA, in addition to the established role of Cdc14 sequestration in coordinating nuclear segregation with mitotic exit.

scholarly journals Role of the p68 Subunit of Human DNA Polymerase α-Primase in Simian Virus 40 DNA Replication

2002 ◽  
Vol 22 (16) ◽  
pp. 5669-5678 ◽  
Author(s):  
Robert D. Ott ◽  
Christoph Rehfuess ◽  
Vladimir N. Podust ◽  
Jill E. Clark ◽  
Ellen Fanning
Keyword(s):  
Dna Replication ◽  
Dna Polymerase ◽  
Essential Role ◽  
Protein A ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
S Phase ◽  
Dna Polymerase Α

ABSTRACT DNA polymerase α-primase (pol-prim) is a heterotetramer with DNA polymerase and primase activities. The polymerase (p180) and primase (p48 and p58) subunits synthesize primers and extend them, but the function of the remaining subunit (p68) is poorly understood. Genetic studies in yeast suggested an essential role for the p68 ortholog in early S phase prior to the hydroxyurea-sensitive step, possibly a regulatory role in initiation of DNA replication, but found no evidence for an essential function of p68 later in S phase. To investigate whether the human p68 subunit has an essential role in DNA replication, we examined the ability of a purified trimeric human pol-prim lacking p68 to initiate simian virus 40 DNA replication in vitro and to synthesize and elongate primers on single-stranded DNA in the presence of T antigen and replication protein A (RPA). Both activities of trimeric pol-prim were defective, but activity was recovered upon addition of separately purified p68. Phosphorylation of p68 by cyclin A-dependent protein kinase also inhibited both activities of pol-prim. The data strongly suggest that the p68 subunit is required for priming activity of pol-prim in the presence of RPA and T antigen, both during initiation at the origin and during lagging strand replication.

Sign in / Sign up

Export Citation Format

Share Document