<i>comK</i> encodes the competence transcription factor, the key regulatory protein for competence development in <i>Bacillus subtilis</i>

Sinderen, Douwe van; Luttinger, Amy; Kong, Liyun; Dubnau, David; Venema, Gerard; Hamoen, Leendert W.

doi:10.1111/j.1365-2958.1995.tb02259.x

Cited by 219 publications

(196 citation statements)

References 29 publications

(10 reference statements)

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“…Expression of comG would be expected to be reduced in a med-deficient mutant, since comG is positively regulated by ComK (50,51). Expression of the comGЈ-ЈlacZ fusion in the wild-type cell was very low in sporulation medium, but it in- The procedure for primer extension is described in Materials and Methods.…”

Section: Resultsmentioning

confidence: 99%

“…In addition, the Spo0A-AbrB system acts on comK regulation independently of the route involving MecA and ClpC, and CodY is also required for nutritional repression of comK (11,12,41,48). The importance of all of this regulation of comK is that ComK is the direct positive regulator of transcription of the late competence genes that encode the apparatus for processing and incorporating exogenous DNA into the cell (12,48,50,51). ComK also activates genes such as sacB, nucA, and recA which are not related to competence development (14,25,49).…”

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confidence: 99%

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A new Bacillus subtilis gene, med, encodes a positive regulator of comK

et al. 1997

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Bacillus subtilis degR, a positive regulator of the production of degradative enzymes, is negatively regulated by the competence transcription factor ComK which is overproduced in mecA null mutants. We used transposon Tn10 to search for a mutation that reduced the repression level of degR caused by a mecA mutation. A new gene exerting positive regulation on comK was obtained and designated med (suppressor of mecA effect on degR). Sequence determination, Northern analysis, and primer extension analyses revealed that the med gene contained an open reading frame (ORF) composed of 317 codons and was transcribed into an approximately 1,250-nucleotide mRNA together with its short downstream gene. The expression of comK is positively regulated by factors such as ComK itself, ComS (SrfA)-MecA, DegU, SinR, and AbrB. Quantitative analyses using comK -lacZ, srfA-lacZ, degU -lacZ, and sinR -lacZ fusions showed that disruption of med caused a significant decrease in comK expression in both mecA ؉ and mecA strains, while expression of srfA, sinR, and degU was not affected by the mutation. An epistatic analysis revealed that overproduction of ComK resulted in alteration of med expression, suggesting a regulatory loop between comK and med. Several possible mechanisms for positive regulation of comK by Med are discussed.

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Section: Resultsmentioning

confidence: 99%

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A new Bacillus subtilis gene, med, encodes a positive regulator of comK

et al. 1997

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“…In addition, overexpression of MecA results in a severe decrease in late competence gene expression (28). Since comK is a regulatory gene required for late competence gene expression (51,54), it was of interest to determine the effect of MecA deficiency on comK expression. A mecA deletion was moved into a comG-lacZ strain (BD2104), and P-galactosidase levels were assayed during growth in CM.…”

Section: Resultsmentioning

confidence: 99%

“…Recent evidence has established that the gene encoding CTF is comK (51), shown previously to be required in vivo for the expression of the late competence genes (52,54). …”

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confidence: 99%

The regulation of competence transcription factor synthesis constitutes a critical control point in the regulation of competence in Bacillus subtilis

Hahn¹,

Kong²,

Dubnau³

1994

J Bacteriol

118

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comK, which encodes the competence transcription factor, is itself transcriptionally activated at the transition from exponential growth to stationary phase in Bacillus subtilis. MecA, a negative regulator of competence, also inhibits comK transcription when overexpressed, and a mec4 null mutation results in comK overexpression. Although null mutations in mecA, as well as in another gene, mecB, are known to bypass the requirements for nearly all of the competence regulatory genes, the comK requirement is not suppressed by mecA inactivation. Various competence reulatory genes (comA srfA, degU, abrB, sin, and spoOA) are shown to be required for the expression of comK srfA transcription is shown to occur equally in cells destined for competence and those destined not to become competent. In contrast, comK transcription is restricted to the presumptive competent cells. These and other results are combined to describe a regulatory pathway for competence.

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“…ComA then activates the transcription initiation of the srf operon, which encodes the competence regulatory peptide ComS (10,11). ComS serves to release the transcriptional activator ComK from its inhibitory complex composed of the proteins MecA and ClpCP (10)(11)(12)(13), so that ComK can stimulate transcription of genes required for DNA uptake in competent cells (14). Interestingly, ComAdependent transcription of srf requires the ATP-dependent protease ClpXP (15,16), which functions to eliminate the 15.4-kDa Spx protein (refs.…”

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confidence: 99%

A regulatory protein that interferes with activator-stimulated transcription in bacteria

Nakano

Zhang

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

129

218

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Transcriptional activator proteins in bacteria often operate by interaction with the C-terminal domain of the ␣-subunit of RNA polymerase (RNAP). Here we report the discovery of an ''anti-␣'' factor Spx in Bacillus subtilis that blocks transcriptional activation by binding to the ␣-C-terminal domain, thereby interfering with the capacity of RNAP to respond to certain activator proteins. Spx disrupts complex formation between the activator proteins ResD and ComA and promoter-bound RNAP, and it does so by direct interaction with the ␣-subunit. ResD-and ComA-stimulated transcription requires the proteolytic elimination of Spx by the ATPdependent protease ClpXP. Spx represents a class of transcriptional regulators that inhibit activator-stimulated transcription by interaction with ␣.Spx ͉ RNA polymerase ͉ ␣-subunit ͉ Bacillus subtilis ͉ transcriptional activation T ranscriptional activation in bacteria involves contacts between DNA-bound activators and promoter-bound RNA polymerase (RNAP). Most such interactions require the ␣-subunit of RNAP, which possesses several activator-interaction surfaces within its C-terminal domain (CTD) (1, 2). One such activator is ComA of the bacterium Bacillus subtilis (3-5), a response regulator, required for transcription of genes involved in the development of genetic competence (6). In response to high cell density, ComA becomes phosphorylated by interaction with its cognate histidine kinase, ComP, that is activated when it binds the pheromone ComX (7-9). ComA then activates the transcription initiation of the srf operon, which encodes the competence regulatory peptide ComS (10, 11). ComS serves to release the transcriptional activator ComK from its inhibitory complex composed of the proteins MecA and ClpCP (10-13), so that ComK can stimulate transcription of genes required for DNA uptake in competent cells (14). Interestingly, ComAdependent transcription of srf requires the ATP-dependent protease ClpXP (15, 16), which functions to eliminate the 15.4-kDa Spx protein (refs. 17 and 18; see Results). A mutation in clpX blocks ComA-activated transcription and has severe effects on growth and development (17). These pleiotropic effects of ClpXP absence can be suppressed either by the elimination of Spx or by missense mutations in the rpoA gene that encodes the RNAP ␣-subunit (refs. 16 and 17; see Results). This latter finding suggested that Spx exerts its negative effect on ComA-mediated transcription, and other transcriptional activation systems, by interaction with RNAP. A similar relationship between Spx and the ␣-subunit of RNAP was observed for ResD-activated transcription (see Results). ResD, like ComA, is a response regulator and transcriptional activator. It is part of the ResDE two-component signal transduction system that is required for the transcription of genes that are induced in response to oxygen limitation (19).In this article we show that Spx interferes with activatorstimulated transcription by interaction with the RNAP ␣-CTD, a mechanism of transcriptional repression ...

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comK encodes the competence transcription factor, the key regulatory protein for competence development in Bacillus subtilis

Cited by 219 publications

References 29 publications

A new Bacillus subtilis gene, med, encodes a positive regulator of comK

A new Bacillus subtilis gene, med, encodes a positive regulator of comK

The regulation of competence transcription factor synthesis constitutes a critical control point in the regulation of competence in Bacillus subtilis

A regulatory protein that interferes with activator-stimulated transcription in bacteria

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