Bacterial Cell Division Regulation: Lysogenization of Conditional Cell Division
 lon
 −
 Mutants of
 Escherichia coli
 by Bacteriophage Lambda

Walker, James R.; Ussery, Christine L.; Allen, Jane S.

doi:10.1128/jb.113.3.1326-1332.1973

Cited by 46 publications

(31 citation statements)

References 33 publications

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“…In addition to filamentation, Ion strains show other phenotypic effects such as the overproduction of capsular polysaccharide, i.e., mucoidy (32,33) and decreased lysogenization of lambda (12,14,55) and P1 phages (53). The Ion mutation also affects the stability of certain abnormal (6,18,19,28,29,36,48) and normal (11,16,38,46) polypeptides.…”

mentioning

confidence: 99%

Regulation of cell division in Escherichia coli: SOS induction and cellular location of the sulA protein, a key to lon-associated filamentation and death

Schoemaker¹,

Gayda²,

Markovitz³

1984

J Bacteriol

136

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Mutations in sulA (sfiA) block the filamentation and death of capR (ion) mutants that occur after treatments that either damage DNA or inhibit DNA replication and thereby induce the SOS response. Previous suiA-iacZ gene fusion studies showed that sulA is transcriptionally regulated by the SOS response system (lexAlrecA). SulA protein has been hypothesized to be additionally regulated proteolytically through the capR (lon) protease, i.e., in lon mutants lacking a functional ATP-dependent protease there would be more SulA protein. A hypothesized function for SulA protein is an inhibitor of cell septation. To investigate aspects of this model, we attempted to construct Ion, Ion sulA, and Ion sulB strains containing multicopy plasmids specifying the suiA+ gene. Multicopy suIA+ plasmids could not be established in Ion strains because more SulA protein accumulates than in a Ion' strain. When the sulA gene was mutated by a mini-Mu transposon the plasmid could be established in the Ion strains. In contrast, suiA+ plasmids could be established in lon+, lon sulA, and Ion sulB strains. The suiA+ plasmids caused Ion sulA and Ion sulB cells to exist as filaments without SOS induction and to be sensitive to UV light and nitrofurantoin. Evidence implicated higher basal levels of SulA protein in these Ion plasmid suiA + strains as the cause of filamentation. We confirmed that the SulA protein is an 18-kilodalton polypeptide and demonstrated that it was induced by treatment with nalidixic acid. The SulA protein was rapidly degraded in a lon+ strain, but was comparatively more stable in vivo in a lon sulB mutant. Furthermore, the SulA protein was localized to the membrane by several techniques. enzymatic activities: an ATP hydrolysis-dependent protease activity (9, 10; M. F. Charette, Ph.D. thesis, University of Chicago, 1981), DNA stimulated ATPase activity (7a), and nucleic acid-binding activity (56; Charette, Ph.D. thesis). In addition, a defective CapR protein (capR9 allele) has also been purified. The CapR9 protein has retained the general nucleic acid affinity (9, 56), but has lost the protease activity (8,9). In Ion mutants, second site mutations in sul (suppressor of Ion) prevent the filamentation and UV sensitivity without affecting the mucoid phenotype of the cells (14,17,26,27). These mutants were isolated as UV-, nitro-NF-, or methyl methanesulfonate-resistant derivatives of lon strains. The sul mutations are located at two loci on the E. coli chromosome; sulA is near pyrD (22 min), and sulB is near leu (2 min). sfiA and sfiB (sfi for suppressor of filament induction) are identical to sulA and suiB, respectively, and were isolated as spontaneous thermoresistant revertants of tif-1 (recA441) Ion strains (15,23,24). The tif-l Ion strains filament and die at 41°C. To account for their data, George et al. (15) proposed that a division inhibitor (product of the sulA or sulB gene?) was induced by UV and that it might be more stable in Ion strains.By means of a Mu d(amp-lac) operon fusion that linked the structural gene for 3...

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confidence: 99%

Regulation of cell division in Escherichia coli: SOS induction and cellular location of the sulA protein, a key to lon-associated filamentation and death

Schoemaker¹,

Gayda²,

Markovitz³

1984

J Bacteriol

136

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“…They filament extensively after treatment with UV light (9) and overproduce capsular polysaccharide (15). In addition, Ion cells are defective in plasmid maintenance and establishment (3,18) and X lysogeny (19).…”

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confidence: 99%

Role of sulA and sulB in filamentation by lon mutants of Escherichia coli K-12

Gottesman¹,

Halpern²,

Trisler³

1981

J Bacteriol

210

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Celis containing the pleiotropic Escherichia coli mutation ion filament extensively and die after exposure to ultraviolet light. Outside suppressors of the ultraviolet sensitivity, called sul, have previously been described at two loci; these mutations reverse the ultraviolet sensitivity of Ion strains but do not affect the mucoidal or degradation defect of these strains. An isogenic set of strains carrying combinations of Ion, suA, and sulB was constructed, and their behavior during normal growth and after ultraviolet treatment was studied. suA mutations had no detectable phenotype in Ion+' cells; the Ion suA strains filamented transiently after ultraviolet irradiation, as did lon' sul' cells. We found that the sulB mutation, which alters cell morphology and slows recovery from transient filamentation after ultraviolet treatment, was epistatic to both Ion and suA. Whereas sulA mutations were recessive to the wild-type allele, sulB was partially dominant. The simplest model to account for our observations is that sulA and Ion participate in a pathway of filamentation independent of that which produces transient filamentation in wild-type strains; sulB product may be the target of suA action and may play a role in normal cell division.

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“…During the establishment of lysogeny, stabilisation of σ 32 by λCIII may lead to elevated production of the bacterial protease lon that is transcribed from heat shock promoters [26] and degrades the phage protein N [27], indirectly helping the lysogenic response. It is known that λ lysogeny is reduced in lon mutants [27,28]. Alternatively, inhibition of HflB by λCIII would lead to increased levels of σ 32 , causing elevated production of the heat shock proteins DnaJ, DnaK and GrpE which promote the replication of λ [29,30].…”

Section: Discussionmentioning

confidence: 99%

Direct CIII–HflB interaction is responsible for the inhibition of the HflB (FtsH)‐mediated proteolysis of Escherichia coliσ³² by λCIII

2008

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Development of the temperate coliphage k depends on a set of phage-specified regulatory proteins that interact with host target proteins [1][2][3][4]. Among several effects on host protein synthesis, k provokes the overproduction of some bacterial proteins induced in the heat shock response. This effect depends on early gene expression encoded by the leftward (p L ) transcription unit of k [5,6]. CIII is a k-specific regulatory protein from the p L operon with a potential for host interaction. It is a small 54-residue protein that favors the lysogenic response to infection by stabilizing kCII, the transcriptional factor that favors lysogeny and is responsible for primary control of the lambda developmental decision for lysis or lysogeny [4,[7][8][9]. In the absence of CIII, CII is rapidly degraded by the ATPdependent host metalloprotease HflB (FtsH). The molecular mechanism for CIII-mediated inhibition of the proteolysis of CII by HflB involves CIII-HflB interaction [10,11]. CIII itself is a substrate of HflB [12]. It has also been reported that CIIIC, the central helical domain of CIII, is resistant to HflB proteolysis, and is a more effective inhibitor than the full-length protein [11].Apart from promoting lysogeny by lambda, CIII protects Escherichia coli r 32 , the heat shock-specific sigma factor, which is also a substrate of HflB [13,14]. This effect generates a heat-shock response in the cell [15,16]. Maximal production of CIII prolongs the heat-induced synthesis of E. coli heat shock proteins even at low temperature [17]. The half-life of r 32 ( 2 min) is increased approximately fourfold upon overproduction of CIII, resulting in an overproduction of heat shock proteins and rapid inhibition of cell growth [15]. The molecular mechanism of the CIIImediated inhibition of proteolysis of r 32 by HflB is unknown.We tried to address this issue by studying the effects of CIII and CIIIC on the proteolysis of

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Bacterial Cell Division Regulation: Lysogenization of Conditional Cell Division lon ⁻ Mutants of Escherichia coli by Bacteriophage Lambda

Cited by 46 publications

References 33 publications

Regulation of cell division in Escherichia coli: SOS induction and cellular location of the sulA protein, a key to lon-associated filamentation and death

Regulation of cell division in Escherichia coli: SOS induction and cellular location of the sulA protein, a key to lon-associated filamentation and death

Role of sulA and sulB in filamentation by lon mutants of Escherichia coli K-12

Direct CIII–HflB interaction is responsible for the inhibition of the HflB (FtsH)‐mediated proteolysis of Escherichia coliσ³² by λCIII

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Bacterial Cell Division Regulation: Lysogenization of Conditional Cell Division lon − Mutants of Escherichia coli by Bacteriophage Lambda

Cited by 46 publications

References 33 publications

Regulation of cell division in Escherichia coli: SOS induction and cellular location of the sulA protein, a key to lon-associated filamentation and death

Regulation of cell division in Escherichia coli: SOS induction and cellular location of the sulA protein, a key to lon-associated filamentation and death

Role of sulA and sulB in filamentation by lon mutants of Escherichia coli K-12

Direct CIII–HflB interaction is responsible for the inhibition of the HflB (FtsH)‐mediated proteolysis of Escherichia coliσ32 by λCIII

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Bacterial Cell Division Regulation: Lysogenization of Conditional Cell Division lon ⁻ Mutants of Escherichia coli by Bacteriophage Lambda

Direct CIII–HflB interaction is responsible for the inhibition of the HflB (FtsH)‐mediated proteolysis of Escherichia coliσ³² by λCIII