安定した微小管を切り離して分解するATPaseであるカタニンの識別
1Department of Pharmacology, University of California, San Francisco 94143.
Cell
|November 5, 1993
まとめ
新しい酵素であるカタニンは,ATPの水解を用いて微小管をチューブリン二重体に分解し,分解する. このプロセスはチューブリン再ポリメリゼーションを可能にし,細胞マイクロチューブルの再編成を支援します.
科学分野:
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
- バイオケミストリー バイオケミストリー
背景:
- ユカリオット細胞は,細胞分裂や移動などの重要なプロセスのために,マイクロチューブルの細胞骨格を動的に再編成します.
- 微小管の分解のメカニズムを理解することは,細胞動態を理解するために不可欠です.
研究 の 目的:
- 微小管の分解に関与するタンパク質であるカタニンを浄化し特徴づけること.
- 微小管の切断におけるカタニンの酵素活性とメカニズムを調査する.
主な方法:
- ヘテロディメアタンパク質カタニンの浄化.
- マイクロチューブルの切断とチューブリン分解を測定するためのアッセイ.
- ATPの水解依存性を判定するための酵素分析.
主要な成果:
- カタニンは,微小管をチューブリン二重体に分割するヘテロディメアタンパク質として精製されました.
- 解体プロセスはチューブリンを不可逆的に変化させず,再ポリマー化が可能です.
- カタニンは,マイクロチューブル刺激によるATPアゼであり,その切断活動にはATPの水解が必要である.
結論:
- カタニンは,ATPの水解を用いて微小管内のチューブリン-チューブリン結合を分解する新しい酵素です.
- この酵素活性は,真核細胞内の複雑なマイクロチューブル配列を分解する上で重要な役割を果たしている可能性が高い.
関連する概念動画
01:27ATP Driven Pumps I: An Overview
ATP-driven pumps, also known as transport ATPases, are integral membrane proteins. They have binding sites for ATP located on the membrane's cytosolic side and the ion-conducting domain in the transmembrane region. These pumps use the free energy released from ATP hydrolysis to move the solutes across cell membranes against an electrochemical gradient.
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are...
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are...
01:28The Inner Mitochondrial Membrane
The inner mitochondrial membrane is the primary site of ATP synthesis. The inner membrane domain that forms a smooth layer adjacent to the outer membrane is called the inner boundary membrane. This domain contains membrane transporters that drive metabolites in and out of the mitochondria. In contrast, the inner membrane network that invaginates into the matrix space is called the cristae membrane. This domain accounts for principle mitochondrial function as it accommodates the protein...
01:48ATP Synthase: Mechanism
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...
01:18ATP Synthase: Structure
ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP...
01:34ATP Driven Pumps II: P-type Pumps
The P-type pumps are a large family of integral membrane transporter ATPases. They are divided into five major types based on substrate specificity, from I to V.
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
01:30ATP Driven Pumps III: V-type Pumps
V-type pumps are ATP-driven pumps found in the vacuolar membranes of plants, yeast, endosomal and lysosomal membranes of animal cells, plasma membranes of a few specialized eukaryotic cells, and some prokaryotes. They are also known as the V1Vo-ATPase, that couple ATP hydrolysis to transport protons against a concentration gradient.
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...