scholarly journals Regulation of the ribonucleotide reductase small subunit gene by DNA-damaging agents in Dictyostelium discoideum

1999 ◽  
Vol 27 (15) ◽  
pp. 3042-3048 ◽  
Author(s):  
P. Gaudet ◽  
A. Tsang
Keyword(s):  
Dictyostelium Discoideum ◽  
Ribonucleotide Reductase ◽  
Small Subunit ◽  
Subunit Gene ◽  
Dna Damaging Agents

Upstream regulatory sequences of the yeast RNR2 gene include a repression sequence and an activation site that binds the RAP1 protein

1989 ◽  
Vol 9 (12) ◽  
pp. 5359-5372
Author(s):  
H K Hurd ◽  
J W Roberts
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribonucleotide Reductase ◽  
Small Subunit ◽  
Methyl Methanesulfonate ◽  
Regulatory Sequences ◽  
Start Site ◽  
Transcription Start ◽  
Dna Damaging Agents ◽  
Number Of Genes ◽  
Upstream Regulatory Sequences

The small subunit of ribonucleotide reductase in Saccharomyces cerevisiae (RNR2) was induced 3- to 20-fold by a variety of DNA-damaging agents. Induction of the RNR2 transcript by at least one of these agents, methyl methanesulfonate, did not require protein synthesis. To identify sequences involved in the regulation of RNR2, we introduced deletions upstream of the transcription start site. Sequences required for induction were contained within a 200-base-pair region that could confer methyl methanesulfonate inducibility on the heterologous CYC1 promoter. This region contained a repression sequence and at least two positive activation sites. One of these activation sites bound RAP1, a protein known to associate with mating-type silencers and the upstream activation sequences of a number of genes. The behavior of deletions of the repression sequence suggests that induction of RNR2 may occur, at least in part, through relief of repression.

scholarly journals Upstream regulatory sequences of the yeast RNR2 gene include a repression sequence and an activation site that binds the RAP1 protein.

1989 ◽  
Vol 9 (12) ◽  
pp. 5359-5372 ◽  
Author(s):  
H K Hurd ◽  
J W Roberts
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribonucleotide Reductase ◽  
Small Subunit ◽  
Methyl Methanesulfonate ◽  
Regulatory Sequences ◽  
Start Site ◽  
Transcription Start ◽  
Dna Damaging Agents ◽  
Number Of Genes ◽  
Upstream Regulatory Sequences

The small subunit of ribonucleotide reductase in Saccharomyces cerevisiae (RNR2) was induced 3- to 20-fold by a variety of DNA-damaging agents. Induction of the RNR2 transcript by at least one of these agents, methyl methanesulfonate, did not require protein synthesis. To identify sequences involved in the regulation of RNR2, we introduced deletions upstream of the transcription start site. Sequences required for induction were contained within a 200-base-pair region that could confer methyl methanesulfonate inducibility on the heterologous CYC1 promoter. This region contained a repression sequence and at least two positive activation sites. One of these activation sites bound RAP1, a protein known to associate with mating-type silencers and the upstream activation sequences of a number of genes. The behavior of deletions of the repression sequence suggests that induction of RNR2 may occur, at least in part, through relief of repression.

scholarly journals Cell Cycle Regulation of the Tobacco Ribonucleotide Reductase Small Subunit Gene Is Mediated by E2F-like Elements

2000 ◽  
Vol 12 (10) ◽  
pp. 1987-1999 ◽  
Author(s):  
Marie-Edith Chabouté ◽  
Bernadette Clément ◽  
Masami Sekine ◽  
Gabriel Philipps ◽  
Nicole Chaubet-Gigot
Keyword(s):  
Cell Cycle ◽  
Ribonucleotide Reductase ◽  
Cell Cycle Regulation ◽  
Small Subunit ◽  
Subunit Gene ◽  
Cycle Regulation

Cell Cycle Regulation of the Tobacco Ribonucleotide Reductase Small Subunit Gene Is Mediated by E2F-Like Elements

2000 ◽  
Vol 12 (10) ◽  
pp. 1987 ◽  
Author(s):  
Marie-Edith Chaboute ◽  
Bernadette Clement ◽  
Masami Sekine ◽  
Gabriel Philipps ◽  
Nicole Chaubet-Gigot
Keyword(s):  
Cell Cycle ◽  
Ribonucleotide Reductase ◽  
Cell Cycle Regulation ◽  
Small Subunit ◽  
Subunit Gene ◽  
Cycle Regulation

DNA damage induction of ribonucleotide reductase

1989 ◽  
Vol 9 (11) ◽  
pp. 4932-4940
Author(s):  
S J Elledge ◽  
R W Davis
Keyword(s):  
Dna Damage ◽  
Stress Response ◽  
Ribonucleotide Reductase ◽  
Uv Light ◽  
Small Subunit ◽  
Lacz Fusion ◽  
Dna Damaging Agents ◽  
Yeast Strains ◽  
Increased Sensitivity ◽  
Beta Galactosidase

RNR2 encodes the small subunit of ribonucleotide reductase, the enzyme that catalyzes the first step in the pathway for the production of deoxyribonucleotides needed for DNA synthesis. RNR2 is a member of a group of genes whose activities are cell cycle regulated and that are transcriptionally induced in response to the stress of DNA damage. An RNR2-lacZ fusion was used to further characterize the regulation of RNR2 and the pathway responsible for its response to DNA damage. beta-Galactosidase activity in yeast strains containing the RNR2-lacZ fusion was inducible in response to DNA-damaging agents (UV light, 4-nitroquinoline-1-oxide [4-NQO], and methyl methanesulfonate [MMS]) and agents that block DNA replication (hydroxyurea [HU] and methotrexate) but not heat shock. When MATa cells were arrested in G1 by alpha-factor, RNR2 mRNA was still inducible by DNA damage, indicating that the observed induction can occur outside of S phase. In addition, RNR2 induction was not blocked by the presence of cycloheximide and is therefore likely to be independent of protein synthesis. A mutation, rnr2-314, was found to confer hypersensitivity to HU and increased sensitivity to MMS. In rnr2-314 mutant strains, the DNA damage stress response was found to be partially constitutive as well as hypersensitive to induction by HU but not MMS. The induction properties of RNR2 were examined in a rad4-2 mutant background; in this genetic background, RNR2 was hypersensitive to induction by 4-NQO but not MMS. Induction of the RNR2-lacZ fusion in a RAD(+) strain in response to 4-NQO was not enhanced by the presence of an equal number of rad4-2 cells that lacked the fusion, implying that the DNA damage stress response in cell autonomous.

scholarly journals DNA damage induction of ribonucleotide reductase.

1989 ◽  
Vol 9 (11) ◽  
pp. 4932-4940 ◽  
Author(s):  
S J Elledge ◽  
R W Davis
Keyword(s):  
Dna Damage ◽  
Stress Response ◽  
Ribonucleotide Reductase ◽  
Uv Light ◽  
Small Subunit ◽  
Lacz Fusion ◽  
Dna Damaging Agents ◽  
Yeast Strains ◽  
Increased Sensitivity ◽  
Beta Galactosidase

RNR2 encodes the small subunit of ribonucleotide reductase, the enzyme that catalyzes the first step in the pathway for the production of deoxyribonucleotides needed for DNA synthesis. RNR2 is a member of a group of genes whose activities are cell cycle regulated and that are transcriptionally induced in response to the stress of DNA damage. An RNR2-lacZ fusion was used to further characterize the regulation of RNR2 and the pathway responsible for its response to DNA damage. beta-Galactosidase activity in yeast strains containing the RNR2-lacZ fusion was inducible in response to DNA-damaging agents (UV light, 4-nitroquinoline-1-oxide [4-NQO], and methyl methanesulfonate [MMS]) and agents that block DNA replication (hydroxyurea [HU] and methotrexate) but not heat shock. When MATa cells were arrested in G1 by alpha-factor, RNR2 mRNA was still inducible by DNA damage, indicating that the observed induction can occur outside of S phase. In addition, RNR2 induction was not blocked by the presence of cycloheximide and is therefore likely to be independent of protein synthesis. A mutation, rnr2-314, was found to confer hypersensitivity to HU and increased sensitivity to MMS. In rnr2-314 mutant strains, the DNA damage stress response was found to be partially constitutive as well as hypersensitive to induction by HU but not MMS. The induction properties of RNR2 were examined in a rad4-2 mutant background; in this genetic background, RNR2 was hypersensitive to induction by 4-NQO but not MMS. Induction of the RNR2-lacZ fusion in a RAD(+) strain in response to 4-NQO was not enhanced by the presence of an equal number of rad4-2 cells that lacked the fusion, implying that the DNA damage stress response in cell autonomous.

scholarly journals Investigation of in Vivo Roles of the C-terminal Tails of the Small Subunit (ββ′) of Saccharomyces cerevisiae Ribonucleotide Reductase

2013 ◽  
Vol 288 (20) ◽  
pp. 13951-13959 ◽  
Author(s):  
Yan Zhang ◽  
Xiuxiang An ◽  
JoAnne Stubbe ◽  
Mingxia Huang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribonucleotide Reductase ◽  
Large Subunit ◽  
Small Subunit ◽  
Cluster Assembly ◽  
E Coli ◽  
Viability Assay ◽  
Docking Model

The small subunit (β2) of class Ia ribonucleotide reductase (RNR) houses a diferric tyrosyl cofactor (Fe2III-Y•) that initiates nucleotide reduction in the large subunit (α2) via a long range radical transfer (RT) pathway in the holo-(α2)m(β2)n complex. The C-terminal tails of β2 are predominantly responsible for interaction with α2, with a conserved tyrosine residue in the tail (Tyr356 in Escherichia coli NrdB) proposed to participate in cofactor assembly/maintenance and in RT. In the absence of structure of any holo-RNR, the role of the β tail in cluster assembly/maintenance and its predisposition within the holo-complex have remained unknown. In this study, we have taken advantage of the unusual heterodimeric nature of the Saccharomyces cerevisiae RNR small subunit (ββ′), of which only β contains a cofactor, to address both of these issues. We demonstrate that neither β-Tyr376 nor β′-Tyr323 (Tyr356 equivalent in NrdB) is required for cofactor assembly in vivo, in contrast to the previously proposed mechanism for E. coli cofactor maintenance and assembly in vitro. Furthermore, studies with reconstituted-ββ′ and an in vivo viability assay show that β-Tyr376 is essential for RT, whereas Tyr323 in β′ is not. Although the C-terminal tail of β′ is dispensable for cofactor formation and RT, it is essential for interactions with β and α to form the active holo-RNR. Together the results provide the first evidence of a directed orientation of the β and β′ C-terminal tails relative to α within the holoenzyme consistent with a docking model of the two subunits and argue against RT across the β β′ interface.

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