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Yoshinori Akiyama - One of the best experts on this subject based on the ideXlab platform.
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Host regulation of lysogenic decision in bacteriophage lambda: transmembrane modulation of FtsH (HflB), the cII degrading protease, by HflKC (HflA).
Proceedings of the National Academy of Sciences of the United States of America, 1997Co-Authors: Akio Kihara, Yoshinori AkiyamaAbstract:The cII gene product of bacteriophage λ is unstable and required for the establishment of Lysogenization. Its intracellular amount is important for the decision between lytic growth and Lysogenization. Two genetic loci of Escherichia coli are crucial for these commitments of infecting λ genome. One of them, hflA encodes the HflKC membrane protein complex, which has been believed to be a protease degrading the cII protein. However, both its absence and overproduction stabilized cII in vivo and the proposed serine protease-like sequence motif in HflC was dispensable for the Lysogenization control. Moreover, the HflKC protein was found to reside on the periplasmic side of the plasma membrane. In contrast, the other host gene, ftsH (hflB) encoding an integral membrane ATPase/protease, is positively required for degradation of cII, since loss of its function stabilized cII and its overexpression accelerated the cII degradation. In vitro, purified FtsH catalyzed ATP-dependent proteolysis of cII and HflKC antagonized the FtsH action. These results, together with our previous finding that FtsH and HflKC form a complex, suggest that FtsH is the cII degrading protease and HflKC is a modulator of the FtsH function. We propose that this transmembrane modulation differentiates the FtsH actions to different substrate proteins such as the membrane-bound SecY protein and the cytosolic cII protein. This study necessitates a revision of the prevailing view about the host control over λ lysogenic decision.
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Cell growth and lambda phage development controlled by the same essential Escherichia coli gene, ftsH/hflB.
Proceedings of the National Academy of Sciences of the United States of America, 1993Co-Authors: Christophe Herman, Yoshinori Akiyama, Teru Ogura, Toshifumi Tomoyasu, Sota Hiraga, Koreaki Ito, René Thomas, Richard D'ari, Philippe BoulocAbstract:Abstract The lambda phage choice between lysis and lysogeny is influenced by certain host functions in Escherichia coli. We found that the frequency of lambda Lysogenization is markedly increased in the ftsH1 temperature-sensitive mutant. The ftsH gene, previously shown to code for an essential inner membrane protein with putative ATPase activity, is identical to hflB, a gene involved in the stability of the phage cII activator protein. The lysogenic decision controlled by FtsH/HflB is independent of that controlled by the protease HflA. Overproduction of FtsH/HflB suppresses the high frequency of Lysogenization in an hflA null mutant. The FtsH/HflB protein, which stimulates cII degradation, may be a component of an HflA-independent proteolytic pathway, or it may act as a chaperone, maintaining cII in a conformation subject to proteolysis via such a pathway. Suppressor mutations of ftsH1 temperature-sensitive lethality, located in the fur gene (coding for the ferric uptake regulator), did not restore FtsH/HflB activity with respect to lambda Lysogenization.
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cell growth and lambda phage development controlled by the same essential escherichia coli gene ftsh hflb
Proceedings of the National Academy of Sciences of the United States of America, 1993Co-Authors: Christophe Herman, Yoshinori Akiyama, Teru Ogura, Toshifumi Tomoyasu, Sota Hiraga, Koreaki Ito, René Thomas, Richard Dari, Philippe BoulocAbstract:Abstract The lambda phage choice between lysis and lysogeny is influenced by certain host functions in Escherichia coli. We found that the frequency of lambda Lysogenization is markedly increased in the ftsH1 temperature-sensitive mutant. The ftsH gene, previously shown to code for an essential inner membrane protein with putative ATPase activity, is identical to hflB, a gene involved in the stability of the phage cII activator protein. The lysogenic decision controlled by FtsH/HflB is independent of that controlled by the protease HflA. Overproduction of FtsH/HflB suppresses the high frequency of Lysogenization in an hflA null mutant. The FtsH/HflB protein, which stimulates cII degradation, may be a component of an HflA-independent proteolytic pathway, or it may act as a chaperone, maintaining cII in a conformation subject to proteolysis via such a pathway. Suppressor mutations of ftsH1 temperature-sensitive lethality, located in the fur gene (coding for the ferric uptake regulator), did not restore FtsH/HflB activity with respect to lambda Lysogenization.
Philippe Bouloc - One of the best experts on this subject based on the ideXlab platform.
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Cell growth and lambda phage development controlled by the same essential Escherichia coli gene, ftsH/hflB.
Proceedings of the National Academy of Sciences of the United States of America, 1993Co-Authors: Christophe Herman, Yoshinori Akiyama, Teru Ogura, Toshifumi Tomoyasu, Sota Hiraga, Koreaki Ito, René Thomas, Richard D'ari, Philippe BoulocAbstract:Abstract The lambda phage choice between lysis and lysogeny is influenced by certain host functions in Escherichia coli. We found that the frequency of lambda Lysogenization is markedly increased in the ftsH1 temperature-sensitive mutant. The ftsH gene, previously shown to code for an essential inner membrane protein with putative ATPase activity, is identical to hflB, a gene involved in the stability of the phage cII activator protein. The lysogenic decision controlled by FtsH/HflB is independent of that controlled by the protease HflA. Overproduction of FtsH/HflB suppresses the high frequency of Lysogenization in an hflA null mutant. The FtsH/HflB protein, which stimulates cII degradation, may be a component of an HflA-independent proteolytic pathway, or it may act as a chaperone, maintaining cII in a conformation subject to proteolysis via such a pathway. Suppressor mutations of ftsH1 temperature-sensitive lethality, located in the fur gene (coding for the ferric uptake regulator), did not restore FtsH/HflB activity with respect to lambda Lysogenization.
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cell growth and lambda phage development controlled by the same essential escherichia coli gene ftsh hflb
Proceedings of the National Academy of Sciences of the United States of America, 1993Co-Authors: Christophe Herman, Yoshinori Akiyama, Teru Ogura, Toshifumi Tomoyasu, Sota Hiraga, Koreaki Ito, René Thomas, Richard Dari, Philippe BoulocAbstract:Abstract The lambda phage choice between lysis and lysogeny is influenced by certain host functions in Escherichia coli. We found that the frequency of lambda Lysogenization is markedly increased in the ftsH1 temperature-sensitive mutant. The ftsH gene, previously shown to code for an essential inner membrane protein with putative ATPase activity, is identical to hflB, a gene involved in the stability of the phage cII activator protein. The lysogenic decision controlled by FtsH/HflB is independent of that controlled by the protease HflA. Overproduction of FtsH/HflB suppresses the high frequency of Lysogenization in an hflA null mutant. The FtsH/HflB protein, which stimulates cII degradation, may be a component of an HflA-independent proteolytic pathway, or it may act as a chaperone, maintaining cII in a conformation subject to proteolysis via such a pathway. Suppressor mutations of ftsH1 temperature-sensitive lethality, located in the fur gene (coding for the ferric uptake regulator), did not restore FtsH/HflB activity with respect to lambda Lysogenization.
Udi Qimron - One of the best experts on this subject based on the ideXlab platform.
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the escherichia coli crispr system protects from λ Lysogenization lysogens and prophage induction
Journal of Bacteriology, 2010Co-Authors: Rotem Edgar, Udi QimronAbstract:We show that phage Lysogenization, lysogens, and prophage induction are all targeted by CRISPR. The results demonstrate that genomic DNA is not immune to the CRISPR system, that the CRISPR system does not require noncytoplasmic elements, and that the system protects from phages entering and exiting the lysogenic cycle.
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The Escherichia coli CRISPR System Protects from Lysogenization,
2010Co-Authors: Prophage Induction, Rotem Edgar, Udi QimronAbstract:We show that phage Lysogenization, lysogens, and prophage induction are all targeted by CRISPR. The results demonstrate that genomic DNA is not immune to the CRISPR system, that the CRISPR system does not require noncytoplasmic elements, and that the system protects from phages entering and exiting the lysogenic cycle. The CRISPR system was recently identified as an adaptive defense mechanism against bacteriophages and extrachromo-somal elements. The function of the CRISPR system in anti-viral defense was demonstrated experimentally for the first time in 2007 by Barrangou et al. for Streptococcus thermophilus (3). CRISPR protection from lytic proliferation of phages and horizontal gene transfer has since been reported for different bacterial species (5, 11, 17). However, studies of the CRISPR response to temperate phages are scarce. It has been shown that Streptococcus pyogenes strains harboring a CRISPR system contain few or no prophages, whereas strains lacking
Christophe Herman - One of the best experts on this subject based on the ideXlab platform.
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Cell growth and lambda phage development controlled by the same essential Escherichia coli gene, ftsH/hflB.
Proceedings of the National Academy of Sciences of the United States of America, 1993Co-Authors: Christophe Herman, Yoshinori Akiyama, Teru Ogura, Toshifumi Tomoyasu, Sota Hiraga, Koreaki Ito, René Thomas, Richard D'ari, Philippe BoulocAbstract:Abstract The lambda phage choice between lysis and lysogeny is influenced by certain host functions in Escherichia coli. We found that the frequency of lambda Lysogenization is markedly increased in the ftsH1 temperature-sensitive mutant. The ftsH gene, previously shown to code for an essential inner membrane protein with putative ATPase activity, is identical to hflB, a gene involved in the stability of the phage cII activator protein. The lysogenic decision controlled by FtsH/HflB is independent of that controlled by the protease HflA. Overproduction of FtsH/HflB suppresses the high frequency of Lysogenization in an hflA null mutant. The FtsH/HflB protein, which stimulates cII degradation, may be a component of an HflA-independent proteolytic pathway, or it may act as a chaperone, maintaining cII in a conformation subject to proteolysis via such a pathway. Suppressor mutations of ftsH1 temperature-sensitive lethality, located in the fur gene (coding for the ferric uptake regulator), did not restore FtsH/HflB activity with respect to lambda Lysogenization.
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cell growth and lambda phage development controlled by the same essential escherichia coli gene ftsh hflb
Proceedings of the National Academy of Sciences of the United States of America, 1993Co-Authors: Christophe Herman, Yoshinori Akiyama, Teru Ogura, Toshifumi Tomoyasu, Sota Hiraga, Koreaki Ito, René Thomas, Richard Dari, Philippe BoulocAbstract:Abstract The lambda phage choice between lysis and lysogeny is influenced by certain host functions in Escherichia coli. We found that the frequency of lambda Lysogenization is markedly increased in the ftsH1 temperature-sensitive mutant. The ftsH gene, previously shown to code for an essential inner membrane protein with putative ATPase activity, is identical to hflB, a gene involved in the stability of the phage cII activator protein. The lysogenic decision controlled by FtsH/HflB is independent of that controlled by the protease HflA. Overproduction of FtsH/HflB suppresses the high frequency of Lysogenization in an hflA null mutant. The FtsH/HflB protein, which stimulates cII degradation, may be a component of an HflA-independent proteolytic pathway, or it may act as a chaperone, maintaining cII in a conformation subject to proteolysis via such a pathway. Suppressor mutations of ftsH1 temperature-sensitive lethality, located in the fur gene (coding for the ferric uptake regulator), did not restore FtsH/HflB activity with respect to lambda Lysogenization.
Rotem Edgar - One of the best experts on this subject based on the ideXlab platform.
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the escherichia coli crispr system protects from λ Lysogenization lysogens and prophage induction
Journal of Bacteriology, 2010Co-Authors: Rotem Edgar, Udi QimronAbstract:We show that phage Lysogenization, lysogens, and prophage induction are all targeted by CRISPR. The results demonstrate that genomic DNA is not immune to the CRISPR system, that the CRISPR system does not require noncytoplasmic elements, and that the system protects from phages entering and exiting the lysogenic cycle.
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The Escherichia coli CRISPR System Protects from Lysogenization,
2010Co-Authors: Prophage Induction, Rotem Edgar, Udi QimronAbstract:We show that phage Lysogenization, lysogens, and prophage induction are all targeted by CRISPR. The results demonstrate that genomic DNA is not immune to the CRISPR system, that the CRISPR system does not require noncytoplasmic elements, and that the system protects from phages entering and exiting the lysogenic cycle. The CRISPR system was recently identified as an adaptive defense mechanism against bacteriophages and extrachromo-somal elements. The function of the CRISPR system in anti-viral defense was demonstrated experimentally for the first time in 2007 by Barrangou et al. for Streptococcus thermophilus (3). CRISPR protection from lytic proliferation of phages and horizontal gene transfer has since been reported for different bacterial species (5, 11, 17). However, studies of the CRISPR response to temperate phages are scarce. It has been shown that Streptococcus pyogenes strains harboring a CRISPR system contain few or no prophages, whereas strains lacking
