サルモネラ菌の毒性の場所の制御は,ATPを感知するリーダーメッセンジャーRNAによるものである
Eun-Jin Lee1, Eduardo A Groisman
1Howard Hughes Medical Institute, Yale School of Medicine, Section of Microbial Pathogenesis, New Haven, Connecticut 06536-0812, USA.
Nature
|June 16, 2012
まとめ
サルモネラ菌は,増加したATPレベルを検知することで,酸性環境を感知し,重要な毒性遺伝子 (mgtC) の発現を促進します. このATP感知メカニズムは,サルモネラ菌の生存と宿主マクロファージ内の毒性にとって極めて重要です.
科学分野:
- 微生物学 微生物学とは
- 分子生物学は分子生物学である.
- パトジェネシス (病原生)
背景:
- サルモネラ・エンテリカ (Salmonella enterica) は,マクロファージの中で生き残る,選択性細胞内病原体である.
- ホスト細胞区間の酸化は,サルモネラ菌の生存とウイルス性遺伝子発現に不可欠です.
- サルモネラ菌が酸性環境を感知するメカニズムは完全に理解されていません.
研究 の 目的:
- サルモネラ菌がマクロファージ内の酸性環境をどのように感知するかを調査する.
- サルモネラ菌のウイルス性遺伝子発現の調節における細胞性ATPレベルの役割を特定する.
- mgtCウイルス性遺伝子の機能とその調節を解明する.
主な方法:
- 媒体の酸性化とATP濃度の上昇がmgtC遺伝子転写に与える影響を調査した.
- ATPを感知する際にmgtCのリーダーメッセンジャーRNAの役割を分析した.
- 変異したmgtCのリーダーメッセンジャーRNAを用いて,ATP反応が欠けていた.
- 変異したmgtCリーダーを持つマウスにおけるサルモネラウイルス性の評価.
主要な成果:
- 細胞内ATP濃度の上昇は,直接の酸化とは無関係にmgtC遺伝子転写を促進する.
- ATPは,mgtCのリーダーメッセンジャーRNAにおける転写と翻訳の結合/解離を通して感知される.
- mgtCのリーダーRNAのATP感知を防ぐ変異は,ウイルス性遺伝子発現とマウスのサルモネラウイルス性を減少させます.
結論:
- サルモネラ菌は,ATPを感知するリーダーメッセンジャーRNAを使用して,mgtCウイルス性遺伝子の発現を調節します.
- このメカニズムは,サルモネラ菌が細胞外酸性状態と細胞内代謝変化 (ATPレベル) を関連付けることを可能にします.
- 病原体は,細胞代謝産物への影響を通して,外部のシグナルを感知することができ,宿主-病原体相互作用に関する新しい視点を提供します.
関連する概念動画
Prokaryotic Transcriptional Activators and Repressors
20.1K
The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...
Transcription of prokaryotic...
20.1K
Transcription Attenuation in Prokaryotes
14.6K
Transcriptional attenuation occurs when RNA transcription is prematurely terminated due to the formation of a terminator mRNA hairpin structure. Bacteria use these hairpins to regulate the transcription process and control the synthesis of several amino acids including histidine, lysine, threonine, and phenylalanine. Transcription attenuation takes place in the non-coding regions of mRNA.
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
14.6K
Translational Regulation
893
Translational regulation in prokaryotes ensures efficient protein synthesis by controlling ribosome access to mRNA. This regulation is mediated by secondary RNA structures, including translational riboswitches, RNA thermometers, and small RNAs (sRNAs), which respond to intracellular and environmental signals to modulate gene expression.Translational RiboswitchesRiboswitches in the leader region of mRNAs can regulate translation by altering the accessibility of the Shine-Dalgarno (SD) sequence,...
893
Global Regulatory Systems
961
Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
961
Gene Regulation in Microbial Communities: Quorum Sensing
960
Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
960
Regulation of Bacterial Virulence
80
Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
80


