-
Categories
-
Pharmaceutical Intermediates
-
Active Pharmaceutical Ingredients
-
Food Additives
- Industrial Coatings
- Agrochemicals
- Dyes and Pigments
- Surfactant
- Flavors and Fragrances
- Chemical Reagents
- Catalyst and Auxiliary
- Natural Products
- Inorganic Chemistry
-
Organic Chemistry
-
Biochemical Engineering
- Analytical Chemistry
-
Cosmetic Ingredient
- Water Treatment Chemical
-
Pharmaceutical Intermediates
Promotion
ECHEMI Mall
Wholesale
Weekly Price
Exhibition
News
-
Trade Service
Recently, the team of Wang Xiaoxue, a researcher at the South China Sea Institute of Oceanology, Chinese Academy of Sciences, discovered a new mechanism by which the bacterial host H-NS protein regulates the "silence-activation" process of prophage.
Related research results, titled Xenogeneic silencing relies on temperature-dependent phosphorylation of the host H-NS protein in Shewanella, were published online in Nucleic Acids Research ("Nucleic Acids Research") on March 8.
Bacteriophages are the most abundant and diverse type of viruses in the ocean.
Like other viruses, phages rely on their hosts for survival and reproduction.
Bacteria and archaea are the natural hosts of phages.
The relationship between the virulent phage and the host can be called "predator and prey".
Once infecting the host, it will directly cause the host cell to lyse and release a large amount of phage.
Mild phage can choose to integrate into the host's genome and maintain a coexistence state with the host in the form of prophage.
The survey of metagenomics found that more than half of the bacteria in the ocean are infected with mild bacteriophages.
The prophages formed can benefit the bacterial host by providing new functions.
The close relationship between them has significantly shaped the biological co-existence of the two.
evolution.
Wang Xiaoxue et al.
found in previous work that prophage plays an important role in bacterial biofilm and host stress response.
However, once the prophage is stimulated by some external cause and enters the lysis cycle, it will cause the death of the host cell.
Therefore, the activation of the prophage needs to be strictly controlled by the host.
Shewanella bacteria are widely distributed in the ocean, including various marine environments such as surface water, deep sea, polar regions, and hydrothermal vents.
Comparative genomics analysis found that horizontal gene transfer elements such as prophage, plasmids and gene islands are the main differences in the genome of Shewanella in different environments, and they are an ideal model for studying the co-evolution of environmental bacteria and prophage.
The research team found in previous studies that the prophage of Shewanella isolated in shallow sediments (Zeng et al.
ISME J, 2016) and deep-sea sediments (Liu et al.
EM, 2019) all interact with bacteria The host establishes a "symbiotic relationship" to help the bacterial host adapt to extreme environments.
Shewanella isolated in a temperature-alternating environment, where the prophage will be excised from the host genome under low temperature conditions, which improves the survival rate of the bacteria at low temperatures.
This shows that the prophage is resistant to the original phage under specific environmental conditions.
Silence-activation determines the fate of the bacterial host.
H-NS is a global transcription repressor encoded by the bacterial host, which silences the prophage integrated into the bacterial genome and plays an important role in activating the prophage under appropriate conditions.
In the logarithmic growth phase, each bacterial cell contains about 10,000-20,000 H-NS proteins, which can bind to the AT-rich region on the DNA to silence the prophage.
However, how do H-NSs of different types of bacteria perceive changes in external environmental signals? Achieve the silence and activation of specific prophage? This problem is a hot and difficult point in cell biology, genetics, and structural biology research.
Liu Xiaoxiao, an associate researcher of the South China Sea Institute of Oceanology and others, discovered that the H-NS in Shewanella "silences" the prophage by recognizing the phage cutting enzyme, and the phosphorylation of the H-NS protein is the key to "silencing" the prophage.
At room temperature, most of the H-NS protein in the cell is phosphorylated.
Phosphorylation of H-NS can silence the expression of cytotoxic genes on the prophage; low temperature promotes the dephosphorylation of H-NS and changes the binding of H-NS to DNA In this way, the H-NS silences the specific prophage and helps Shewanella adapt to the low temperature environment. The study found for the first time that bacteria convert changes in external temperature into changes in the phosphorylation level of H-NS protein in the cell, indicating that the "post-translational modification" of H-NS protein can be used as a "molecular switch" to achieve "silencing of specific prophage"- Activate the precise regulation.
Related research results provide a new understanding of how bacteria "silence" foreign genes and integrate them into the host, as well as the co-evolution process of bacteria and phages.
Liu Xiaoxiao is the first author of the paper, and Wang Xiaoxue is the corresponding author of the paper.
The research work was funded by the National Science Fund for Distinguished Young Scholars, the key projects of the National Science Foundation of China's Hydrosphere Microbiology Research Program, the National Key Research and Development Program, and the Major Special Project of Guangdong Laboratory of Southern Ocean Science and Engineering (Guangzhou).
The precise regulation mechanism of host H-NS protein on the "silence-activation" of prophage CP4So Source: South China Sea Institute of Oceanology, Chinese Academy of Sciences
Related research results, titled Xenogeneic silencing relies on temperature-dependent phosphorylation of the host H-NS protein in Shewanella, were published online in Nucleic Acids Research ("Nucleic Acids Research") on March 8.
Bacteriophages are the most abundant and diverse type of viruses in the ocean.
Like other viruses, phages rely on their hosts for survival and reproduction.
Bacteria and archaea are the natural hosts of phages.
The relationship between the virulent phage and the host can be called "predator and prey".
Once infecting the host, it will directly cause the host cell to lyse and release a large amount of phage.
Mild phage can choose to integrate into the host's genome and maintain a coexistence state with the host in the form of prophage.
The survey of metagenomics found that more than half of the bacteria in the ocean are infected with mild bacteriophages.
The prophages formed can benefit the bacterial host by providing new functions.
The close relationship between them has significantly shaped the biological co-existence of the two.
evolution.
Wang Xiaoxue et al.
found in previous work that prophage plays an important role in bacterial biofilm and host stress response.
However, once the prophage is stimulated by some external cause and enters the lysis cycle, it will cause the death of the host cell.
Therefore, the activation of the prophage needs to be strictly controlled by the host.
Shewanella bacteria are widely distributed in the ocean, including various marine environments such as surface water, deep sea, polar regions, and hydrothermal vents.
Comparative genomics analysis found that horizontal gene transfer elements such as prophage, plasmids and gene islands are the main differences in the genome of Shewanella in different environments, and they are an ideal model for studying the co-evolution of environmental bacteria and prophage.
The research team found in previous studies that the prophage of Shewanella isolated in shallow sediments (Zeng et al.
ISME J, 2016) and deep-sea sediments (Liu et al.
EM, 2019) all interact with bacteria The host establishes a "symbiotic relationship" to help the bacterial host adapt to extreme environments.
Shewanella isolated in a temperature-alternating environment, where the prophage will be excised from the host genome under low temperature conditions, which improves the survival rate of the bacteria at low temperatures.
This shows that the prophage is resistant to the original phage under specific environmental conditions.
Silence-activation determines the fate of the bacterial host.
H-NS is a global transcription repressor encoded by the bacterial host, which silences the prophage integrated into the bacterial genome and plays an important role in activating the prophage under appropriate conditions.
In the logarithmic growth phase, each bacterial cell contains about 10,000-20,000 H-NS proteins, which can bind to the AT-rich region on the DNA to silence the prophage.
However, how do H-NSs of different types of bacteria perceive changes in external environmental signals? Achieve the silence and activation of specific prophage? This problem is a hot and difficult point in cell biology, genetics, and structural biology research.
Liu Xiaoxiao, an associate researcher of the South China Sea Institute of Oceanology and others, discovered that the H-NS in Shewanella "silences" the prophage by recognizing the phage cutting enzyme, and the phosphorylation of the H-NS protein is the key to "silencing" the prophage.
At room temperature, most of the H-NS protein in the cell is phosphorylated.
Phosphorylation of H-NS can silence the expression of cytotoxic genes on the prophage; low temperature promotes the dephosphorylation of H-NS and changes the binding of H-NS to DNA In this way, the H-NS silences the specific prophage and helps Shewanella adapt to the low temperature environment. The study found for the first time that bacteria convert changes in external temperature into changes in the phosphorylation level of H-NS protein in the cell, indicating that the "post-translational modification" of H-NS protein can be used as a "molecular switch" to achieve "silencing of specific prophage"- Activate the precise regulation.
Related research results provide a new understanding of how bacteria "silence" foreign genes and integrate them into the host, as well as the co-evolution process of bacteria and phages.
Liu Xiaoxiao is the first author of the paper, and Wang Xiaoxue is the corresponding author of the paper.
The research work was funded by the National Science Fund for Distinguished Young Scholars, the key projects of the National Science Foundation of China's Hydrosphere Microbiology Research Program, the National Key Research and Development Program, and the Major Special Project of Guangdong Laboratory of Southern Ocean Science and Engineering (Guangzhou).
The precise regulation mechanism of host H-NS protein on the "silence-activation" of prophage CP4So Source: South China Sea Institute of Oceanology, Chinese Academy of Sciences
