開発的に調節されたミトコンドリア融合は,保存された,新しい,予測されたGTPaseによって媒介されます
1Department of Genetics, Stanford University School of Medicine, California 94305, USA.
Cell
|July 11, 1997
まとめ
ぼんやりとしたオニオン (fzo) 遺伝子は,ドロソフィラのミトコンドリア融合に不可欠です. fzoの変異は,このプロセスを妨害し,欠陥のある精子の発達のために男性の不妊症につながる.
科学分野:
- 細胞生物学 細胞生物学
- 遺伝学 遺伝学とは
- 発達生物学 発達生物学とは
背景:
- ミトコンドリア融合は,細胞の機能と発達に不可欠です.
- ミトコンドリア融合を調節するメカニズムは,特に精子のような特殊な細胞では,完全に理解されていません.
研究 の 目的:
- ドロソフィラの精子生成中にミトコンドリア融合のタンパク質媒介体を特定し,特徴づけること.
- ミトコンドリア動態におけるぼんやりとした洋 (fzo) 遺伝子の機能と調節を調査する.
主な方法:
- ドロソフィラ・メラノガスターのfzo遺伝子変異の分析.
- 発育中の精子類におけるFzoタンパク質の局所化研究.
- GTP結合ドメインに対する突然変異の影響を調査する.
主要な成果:
- ドロソフィラfzo遺伝子は,精子類のミトコンドリア融合に不可欠な新しいトランスメブランGTPaseをコードします.
- fzo変異した雄はミトコンドリア融合に欠陥があり,不妊です.
- Fzoタンパク質は融合時にミトコンドリアに局所化し,GTP結合によって調節されます.
結論:
- Fzoは,ミトコンドリア融合の最初に特定されたタンパク質メディエーターです.
- Fzoは,ドロソフィラの機能性精子の発達に重要な役割を果たしています.
- Fzoのホモログは他の生物にも存在し,ミトコンドリア融合における役割が保存されていることを示唆しています.
関連する概念動画
02:14GTPases and their Regulation
Guanine nucleotide-binding proteins (G-proteins), also known as GTPases, are a superfamily of proteins that regulate many cellular processes, such as cell signaling, vesicular transport, and the regulation of cell shape and motility. Mutation or dysfunction of these proteins can lead to disease. There are around 40,000 known G-proteins that can broadly be classified into two groups ‒ small G-proteins consisting of a single domain and large multi-domain G-proteins.
Large G-proteins, also known...
Large G-proteins, also known...
01:39Mitochondrial Protein Sorting
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Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
01:19Translocation of Proteins into the Mitochondria
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
01:37Energy to Drive Translocation
Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...
Generally, polypeptides are unfolded by two distinct...
02:14GTPases and their Regulation
Guanine nucleotide-binding proteins (G-proteins), also known as GTPases, are a superfamily of proteins that regulate many cellular processes, such as cell signaling, vesicular transport, and the regulation of cell shape and motility. Mutation or dysfunction of these proteins can lead to disease. There are around 40,000 known G-proteins that can broadly be classified into two groups ‒ small G-proteins consisting of a single domain and large multi-domain G-proteins.
Large G-proteins, also known...
Large G-proteins, also known...
01:25Rab Cascades
Rab GTPases act in a regulated cascade during membrane fusion, helping the lipid bilayers mix. The Rab family of proteins are active when bound to GTP, and inactive when bound to GDP. Hence, they act as guanine nucleotide-dependent molecular switches. Rab-GTP recognizes and binds to long or short-range tethering proteins to capture the target vesicle. These tethers coordinate with SNAREs on the vesicle and the target membrane to assemble the trans SNARE complex that locks the mixing bilayers.