Limits...
The Protein Level of Rev1, a TLS Polymerase in Fission Yeast, Is Strictly Regulated during the Cell Cycle and after DNA Damage.

Uchiyama M, Terunuma J, Hanaoka F - PLoS ONE (2015)

Bottom Line: Interestingly, the protein levels of Rev1 peaked during G1 phase and then decreased dramatically at the entry of S phase; this regulation was dependent on the proteasome.Besides these effects during the cell cycle, we also observed upregulation of Rev1 protein upon DNA damage.This upregulation was abolished when rad3, a checkpoint protein, was deleted or when the Rev1 promoter was replaced with a constitutive promoter.

View Article: PubMed Central - PubMed

Affiliation: Institute for Biomolecular Science, Faculty of Science, Gakushuin University, Toshima-ku, Tokyo, Japan.

ABSTRACT
Translesion DNA synthesis provides an alternative DNA replication mechanism when template DNA is damaged. In fission yeast, Eso1 (polη), Kpa1/DinB (polκ), Rev1, and Polζ (a complex of Rev3 and Rev7) have been identified as translesion synthesis polymerases. The enzymatic characteristics and protein-protein interactions of these polymerases have been intensively characterized; however, how these proteins are regulated during the cell cycle remains unclear. Therefore, we examined the cell cycle oscillation of translesion polymerases. Interestingly, the protein levels of Rev1 peaked during G1 phase and then decreased dramatically at the entry of S phase; this regulation was dependent on the proteasome. Temperature-sensitive proteasome mutants, such as mts2-U31 and mts3-U32, stabilized Rev1 protein when the temperature was shifted to the restrictive condition. In addition, deletion of pop1 or pop2, subunits of SCF ubiquitin ligase complexes, upregulated Rev1 protein levels. Besides these effects during the cell cycle, we also observed upregulation of Rev1 protein upon DNA damage. This upregulation was abolished when rad3, a checkpoint protein, was deleted or when the Rev1 promoter was replaced with a constitutive promoter. From these results, we hypothesize that translesion DNA synthesis is strictly controlled through Rev1 protein levels in order to avoid unwanted mutagenesis.

No MeSH data available.


Related in: MedlinePlus

A model for the protein level regulation of Rev1 and TLS.In G1 phase, Rev1 is abundant and Rev1-dependent loading of TLS polymerase may occur. At the onset of S phase, Rev1 is destroyed in a SCF-dependent manner and chromatin-loaded Eso1/polη serves as an initiator of TLS. When DNA is damaged, the DNA structure checkpoint increases the protein level of Rev1 and facilitates polymerase switching among TLS polymerases.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4493104&req=5

pone.0130000.g008: A model for the protein level regulation of Rev1 and TLS.In G1 phase, Rev1 is abundant and Rev1-dependent loading of TLS polymerase may occur. At the onset of S phase, Rev1 is destroyed in a SCF-dependent manner and chromatin-loaded Eso1/polη serves as an initiator of TLS. When DNA is damaged, the DNA structure checkpoint increases the protein level of Rev1 and facilitates polymerase switching among TLS polymerases.

Mentions: Taking all of the results into consideration, we have proposed a model for Rev1 regulation, as shown in Fig 8. When cells are in the G1 phase, Rev1 is abundant compared to Eso1/polη or polζ. In S phase, Eso1/polη becomes abundant and TLS may be conducted mainly by Eso1/polη as reported previously [73]. When the cell experiences DNA damage, Rev1 is upregulated in a Rad3-dependent manner. This upregulation facilitates the complex formation and the switching of TLS polymerase depending on the type of DNA damage. Further analyses are necessary; however, this hypothesis explains the current findings.


The Protein Level of Rev1, a TLS Polymerase in Fission Yeast, Is Strictly Regulated during the Cell Cycle and after DNA Damage.

Uchiyama M, Terunuma J, Hanaoka F - PLoS ONE (2015)

A model for the protein level regulation of Rev1 and TLS.In G1 phase, Rev1 is abundant and Rev1-dependent loading of TLS polymerase may occur. At the onset of S phase, Rev1 is destroyed in a SCF-dependent manner and chromatin-loaded Eso1/polη serves as an initiator of TLS. When DNA is damaged, the DNA structure checkpoint increases the protein level of Rev1 and facilitates polymerase switching among TLS polymerases.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493104&req=5

pone.0130000.g008: A model for the protein level regulation of Rev1 and TLS.In G1 phase, Rev1 is abundant and Rev1-dependent loading of TLS polymerase may occur. At the onset of S phase, Rev1 is destroyed in a SCF-dependent manner and chromatin-loaded Eso1/polη serves as an initiator of TLS. When DNA is damaged, the DNA structure checkpoint increases the protein level of Rev1 and facilitates polymerase switching among TLS polymerases.
Mentions: Taking all of the results into consideration, we have proposed a model for Rev1 regulation, as shown in Fig 8. When cells are in the G1 phase, Rev1 is abundant compared to Eso1/polη or polζ. In S phase, Eso1/polη becomes abundant and TLS may be conducted mainly by Eso1/polη as reported previously [73]. When the cell experiences DNA damage, Rev1 is upregulated in a Rad3-dependent manner. This upregulation facilitates the complex formation and the switching of TLS polymerase depending on the type of DNA damage. Further analyses are necessary; however, this hypothesis explains the current findings.

Bottom Line: Interestingly, the protein levels of Rev1 peaked during G1 phase and then decreased dramatically at the entry of S phase; this regulation was dependent on the proteasome.Besides these effects during the cell cycle, we also observed upregulation of Rev1 protein upon DNA damage.This upregulation was abolished when rad3, a checkpoint protein, was deleted or when the Rev1 promoter was replaced with a constitutive promoter.

View Article: PubMed Central - PubMed

Affiliation: Institute for Biomolecular Science, Faculty of Science, Gakushuin University, Toshima-ku, Tokyo, Japan.

ABSTRACT
Translesion DNA synthesis provides an alternative DNA replication mechanism when template DNA is damaged. In fission yeast, Eso1 (polη), Kpa1/DinB (polκ), Rev1, and Polζ (a complex of Rev3 and Rev7) have been identified as translesion synthesis polymerases. The enzymatic characteristics and protein-protein interactions of these polymerases have been intensively characterized; however, how these proteins are regulated during the cell cycle remains unclear. Therefore, we examined the cell cycle oscillation of translesion polymerases. Interestingly, the protein levels of Rev1 peaked during G1 phase and then decreased dramatically at the entry of S phase; this regulation was dependent on the proteasome. Temperature-sensitive proteasome mutants, such as mts2-U31 and mts3-U32, stabilized Rev1 protein when the temperature was shifted to the restrictive condition. In addition, deletion of pop1 or pop2, subunits of SCF ubiquitin ligase complexes, upregulated Rev1 protein levels. Besides these effects during the cell cycle, we also observed upregulation of Rev1 protein upon DNA damage. This upregulation was abolished when rad3, a checkpoint protein, was deleted or when the Rev1 promoter was replaced with a constitutive promoter. From these results, we hypothesize that translesion DNA synthesis is strictly controlled through Rev1 protein levels in order to avoid unwanted mutagenesis.

No MeSH data available.


Related in: MedlinePlus