Survival and induction of SOS in Escherichia coli treated with cisplatin, UV-irradiation, or mitomycin C are dependent on the function of the RecBC and RecFOR pathways of homologous recombination

Keller, Kimberly L.; Overbeck-Carrick, Terri L.; Beck, Doris J.

doi:10.1016/s0921-8777(01)00077-5

Cited by 75 publications

(57 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4E and F). Although the repair of MC cross-links can cause a reduced rate of DNA synthesis (86) and SOS induction (87,88), likely owing to double-strand breaks (89), significant inhibition of total DNA synthesis did not occur under our conditions. However, all drug treatments which blocked DNA replication or chromosome segregation produced a nucleoid centered about mid-cell.…”

Section: Discussionmentioning

confidence: 81%

A Replication-Inhibited Unsegregated Nucleoid at Mid-Cell Blocks Z-Ring Formation and Cell Division Independently of SOS and the SlmA Nucleoid Occlusion Protein in Escherichia coli

Cambridge¹,

Blinkova²,

Magnan³

et al. 2013

Journal of Bacteriology

View full text Add to dashboard Cite

Chromosome replication and cell division of Escherichia coli are coordinated with growth such that wild-type cells divide once and only once after each replication cycle. To investigate the nature of this coordination, the effects of inhibiting replication on Z-ring formation and cell division were tested in both synchronized and exponentially growing cells with only one replicating chromosome. When replication elongation was blocked by hydroxyurea or nalidixic acid, arrested cells contained one partially replicated, compact nucleoid located mid-cell. Cell division was strongly inhibited at or before the level of Z-ring formation. DNA cross-linking by mitomycin C delayed segregation, and the accumulation of about two chromosome equivalents at mid-cell also blocked Z-ring formation and cell division. Z-ring inhibition occurred independently of SOS, SlmA-mediated nucleoid occlusion, and MinCDE proteins and did not result from a decreased FtsZ protein concentration. We propose that the presence of a compact, incompletely replicated nucleoid or unsegregated chromosome masses at the normal mid-cell division site inhibits Z-ring formation and that the SOS system, SlmA, and MinC are not required for this inhibition. Bacterial DNA replication and cell division are coordinated with growth so that a single, timely division follows each genome duplication. This rule, however, is complicated by the fact that cells can divide rapidly, with the replication and division machinery operating continuously and concurrently (e.g., see reference 1). Division at mid-cell, which occurs with high precision (2, 3), begins with polymerization of the FtsZ protein into a circumferential ring on the cytoplasmic membrane inner surface (4). Although division frequency is ultimately determined by growth rate (5, 6), regulatory mechanisms control both the location and timing of FtsZ ring assembly (for recent reviews, see the works of de Boer [7], Chien et al. [8], Lutkenhaus et al. [9], and Egan and Vollmer [10]).Placement of Z rings mid-cell depends on negative activities of the Min proteins and nucleoid occlusion. The MinC protein of Escherichia coli binds to FtsZ, preventing Z-ring assembly at all positions except at mid-cell, where its time-averaged concentration is lowest (11-13). The nucleoid occlusion (14) proteins SlmA and Noc, of E. coli and Bacillus subtilis, respectively (15, 16), bind DNA at specific sequences and prevent division over replicating nucleoids in rapidly growing cells. SlmA prevents Z-ring formation by also binding FtsZ (17, 18); the Noc protein functions similarly but has not been shown to bind FtsZ directly (19). Because the SlmA and Noc DNA binding sites are absent from the terminus domain, which is replicated last and in the cell center (20-23), nucleoid occlusion contributes to both spatial and temporal control of Z-ring formation (17)(18)(19)). An slmA null mutant which is also min null frequently forms Z-ring-like structures over nucleoids when grown in LB medium (15). However, the SlmA protein might not be the ...

show abstract

Section: Discussionmentioning

confidence: 81%

A Replication-Inhibited Unsegregated Nucleoid at Mid-Cell Blocks Z-Ring Formation and Cell Division Independently of SOS and the SlmA Nucleoid Occlusion Protein in Escherichia coli

Cambridge¹,

Blinkova²,

Magnan³

et al. 2013

Journal of Bacteriology

View full text Add to dashboard Cite

show abstract

“…3C). Both ␥ radiation and MMC treatment produce a high density of double strand breaks in the genome (17), while UVC produces the maximum number of single strand breaks and less than 1% double strand breaks in the genome (6). The unique effect of PQQ in response to ␥ radiation and MMC clearly indicated the role of PQQ in the regulation of DNA double strand break repair.…”

Section: Resultsmentioning

confidence: 99%

Involvement of a Protein Kinase Activity Inducer in DNA Double Strand Break Repair and Radioresistance of Deinococcus radiodurans

2008

View full text Add to dashboard Cite

Transgenic bacteria producing pyrroloquinoline quinone, a known cofactor for dehydrogenases and an inducer of a periplasmic protein kinase activity, show resistance to both oxidative stress and protection from nonoxidative effects of radiation and DNA-damaging agents. Deinococcus radiodurans R1 encodes an active pyrroloquinoline quinone synthase, and constitutive synthesis of pyrroloquinoline quinone occurred in wildtype bacteria. Disruption of a genomic copy of pqqE resulted in cells that lacked this cofactor. The mutant showed a nearly 3-log decrease in ␥ radiation resistance and a 2-log decrease in mitomycin C tolerance compared to wild-type cells. The mutant cells did not show sensitivity to UVC radiation. Expression of pyrroloquinoline quinone synthase in trans showed that there was functional complementation of ␥ resistance and mitomycin C tolerance in the pqqE mutant. The sensitivity to ␥ radiation was due to impairment or slow kinetics of DNA double strand break repair. Low levels of 32 P incorporation were observed in total soluble proteins of mutant cells compared to the wild type. The results suggest that pyrroloquinoline quinone has a regulatory role as a cofactor for dehydrogenases and an inducer of selected protein kinase activity in radiation resistance and DNA strand break repair in a radioresistant bacterium.Pyrroloquinoline quinone (PQQ) has been shown to be a redox cofactor for periplasmic as well as cytosolic dehydrogenases, contributing to the mineral phosphate solubilization phenotype in bacteria (11). This compound has been reported to act as an antioxidant in vitro (33), in animal systems (13), and in bacterial systems (18) in vivo and as a member of the B group vitamins (16). He and coworkers (13) have shown that the antioxidant nature of PQQ is concentration dependent. Higher concentrations of PQQ induce oxidative stress for mitochondrial activity in rats, which leads to both apoptotic and necrotic cell death. Further studies indicated that the necrotic cell death could be selectively inhibited in the presence of antioxidants, while apoptotic cell death continued by a stillunknown mechanism. Further, a possible role for PQQ as an inducer for proteins kinases involved in distinctly different metabolic and physiological processes has been suggested (20).Deinococcus radiodurans R1, a gram-positive bacterium, exhibits extraordinary tolerance to various abiotic stresses, including radiation, desiccation, and other DNA-damaging factors (3). DNA double strand break repair in D. radiodurans R1 follows biphasic kinetics (8). Phase I is RecA independent and involves an extended synthesis-dependent strand annealing mechanism for reassembly of the fragmented genome (42), while phase II involves RecA-dependent slow crossover events (9). The extreme phenotypes of this bacterium are believed to be due to the presence of an efficient DNA strand break repair mechanism (1, 31) and strong oxidative stress tolerance (27). A comparison of the genome sequence of D. radiodurans R1 (41) with the genome sequenc...

show abstract

“…Caution is needed in interpreting the pBHRF results, because the assay reflects only extrachromosomal recombination; however, this finding is in agreement with the results of studies in knockout yeast and chicken B cells that also suggest that REV3 plays an important role in chromosomal homologous recombination (37,38). Homologous recombination is important to the survival of cells after cisplatin exposure (39 -41), and it may be essential for repair of interstrand cross-links (42)(43)(44). The finding that cisplatin exposure enhances pBHRF recombination suggests that cisplatin up-regulates this putatively nonmutagenic repair mechanism, an effect expected to improve the ability of the cell to survive the DNA damage produced by this agent.…”

Section: Discussionmentioning

confidence: 99%

DNA Polymerase ζ Regulates Cisplatin Cytotoxicity, Mutagenicity, and The Rate of Development of Cisplatin Resistance

Lin²,

Okuda³

et al. 2004

Cancer Research

101

View full text Add to dashboard Cite

DNA polymerase participates in translesional bypass replication. Here we show that reduced expression of the catalytic subunit hREV3 renders human fibroblasts more sensitive to the cytotoxic effect of cisplatin, reduces their sensitivity to the ability of cisplatin exposure to generate drug resistant variants in the surviving population, and reduces the rate of emergence of resistance to cisplatin at the population level. Reduction of REV3 mRNA did not alter the rate of cisplatin adduct removal but did impair both spontaneous and cisplatin-induced extrachromosomal homologous recombination and attenuated bypass replication as reflected by reduced ability to express luciferase from a platinated plasmid. Cisplatin induced a concentration-and time-dependent increase in hREV3 mRNA. The results indicate that, following formation of cisplatin adducts in DNA, REV3 mRNA levels increase, and polymerase functions to promote both cell survival and the generation of drug-resistant variants in the surviving population. We conclude that when cisplatin adducts are present in the DNA, polymerase is an important contributor to cisplatin-induced genomic instability and the subsequent emergence of resistance to this chemotherapeutic agent.

show abstract

Survival and induction of SOS in Escherichia coli treated with cisplatin, UV-irradiation, or mitomycin C are dependent on the function of the RecBC and RecFOR pathways of homologous recombination

Cited by 75 publications

References 26 publications

A Replication-Inhibited Unsegregated Nucleoid at Mid-Cell Blocks Z-Ring Formation and Cell Division Independently of SOS and the SlmA Nucleoid Occlusion Protein in Escherichia coli

A Replication-Inhibited Unsegregated Nucleoid at Mid-Cell Blocks Z-Ring Formation and Cell Division Independently of SOS and the SlmA Nucleoid Occlusion Protein in Escherichia coli

Involvement of a Protein Kinase Activity Inducer in DNA Double Strand Break Repair and Radioresistance of Deinococcus radiodurans

DNA Polymerase ζ Regulates Cisplatin Cytotoxicity, Mutagenicity, and The Rate of Development of Cisplatin Resistance

Contact Info

Product

Resources

About