mRNAキャップ結合タンパク質であるABH1は,アラビドプシス菌の早期アブシシ酸信号伝導を調節する
V Hugouvieux1, J M Kwak, J I Schroeder
1Division of Biology, Cell and Developmental Biology Section, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
Cell
|August 30, 2001
まとめ
植物ホルモンアブシシ酸 (ABA) は,ストレス反応を調節する. 新しい変異体abh1は,ABA過敏性を示し,ABH1を明らかにしています.
科学分野:
- 植物生物学 植物生物学
- 分子遺伝学 分子遺伝学
- 植物ホルモンのシグナル伝達
背景:
- アブシシ酸 (ABA) などの植物ホルモンは,植物のストレス反応と発達を調節するために不可欠です.
- ABAシグナリングの基礎となる分子メカニズムを理解することは,作物の回復力を改善するために不可欠です.
研究 の 目的:
- アブシシ酸 (ABA) シグナル伝達に影響する新型変異体を分離し,特徴づけること.
- ABA反応におけるABH1遺伝子の機能を明らかにする.
主な方法:
- ABA過敏性突然変異体の分離とフェノタイプ分析.
- 遺伝子解析とABH1遺伝子の分子クローン.
- mRNAキャップ・バインディングアッセイとDNAチップ分析.
- ストマタル反応と干ばつ耐性に関する生理学的測定.
主要な成果:
- ABAに特異的な過敏性を示すリセシブ変異体,abh1が特定されました.
- ABH1は,核mRNAのキャップ結合タンパク質のアラビドプシスホモログをコードし,ヘテロディメア複合体で機能します.
- DNAチップ解析は,ABA信号伝達に関与するものを含む,abh1における特定のトランスクリプトのダウンレギュレーションを明らかにした.
- abh1変異体は,ABA過敏性ストマタル閉塞,干ばつによる枯渇の減少,およびガード細胞における増幅された細胞塩酸カルシウム増加を示した.
結論:
- ABH1はABAシグナル伝達の調節剤として作用し,おそらく初期のABAシグナル伝達のコンポーネントの転写を変更する.
- mRNAキャップ結合におけるABH1タンパク質の役割は,正常なABA信号伝導に不可欠である.
- この研究は,ABAシグナル伝達経路の規制に関する新しい洞察を,転写後のレベルで提供しています.
関連する概念動画
Transcription Attenuation in Prokaryotes
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...
Riboswitches
Riboswitches are non-coding mRNA domains that regulate the transcription and translation of downstream genes without the help of proteins. Riboswitches bind directly to a metabolite and can form unique stem-loop or hairpin structures in response to the amount of the metabolite present. They have two distinct regions – a metabolite-binding aptamer and an expression platform.
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
Cotranslational Protein Translocation
Translocation of proteins across membranes is an ancient process that occurs even in bacteria and archaebacteria. In fact, the components of the translocation machinery are still conserved between prokaryotes and eukaryotes.
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
Cell Signaling in Plants
Plant cells communicate to coordinate their cycle of growth, flowering and fruiting, and activities in roots, shoots, and leaves in response to the changing environmental conditions. Plant signaling is distinct from animal signaling. Plants primarily utilize enzyme-linked receptors, whereas the largest class of cell-surface receptors in animals are G-protein coupled receptors (GPCRs). Unlike animals, receptor tyrosine kinases are rare in plants. Instead, plants have a diverse class of...
Translational Regulation
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,...


