TTYH2 と APOE の間の相互作用は,内体脂質の移転を容易にする

Anastasiia Sukalskaia¹, Andreas Karner², Anna Pugnetti¹

¹Department of Biochemistry University of Zurich, Zurich, Switzerland.

Nature

|June 25, 2025

まとめ

Tweety ホモログのTTYH2タンパク質はAPOEと相互作用し,脂質タンパク質から細胞への脂質移動を促進する. この発見は膜脂質抽出のための新しいメカニズムを明らかにし特に脳で関連しています

科学分野:

生物化学
細胞生物学
構造生物学

背景:

ツィーティーホモログ (TTYHs) は,脂質移転における提案されているが証明されていない役割を持つ真核膜タンパク質である.
脂質輸送におけるTTYH2の特異的な機能は,実験的な証拠がないため,仮説のままでした.

研究の目的:

脂質移転におけるTTYH2の機能を調査する.
TTYH2の相互作用パートナーを特定し,その作用メカニズムを明らかにする.

主な方法:

TTYH2の相互作用相手を特定するための内生タンパク質プルダウンアッセイ.
タンパク質の局所化を決定するサブセルラー分化と免疫細胞化学.
APOE-TTYH2の相互作用を特徴付けるための結合試験と構造研究 (複雑な構造を含む).
インビトロ脂質移転試験

主要な成果:

APOEはヒトTTYH2の相互作用パートナーとして特定されました.
TTYH2とAPOEは内分体区間にコロカライズする.
構造的研究により,TTYH2がAPOEを含むリポタンパク質に結合し,膜拡散のための脂質を位置づけることが明らかになった.
TTYH2は,インビトロで脂質の移転を加速することが示された.
TTYH2は,内細胞化されたAPOEを含むリポタンパク質の排出を促進します.

結論:

TTYH2は,エンドサイトーシス後のAPOEを含むリポタンパク質からの脂質の排出に重要な役割を果たします.
この研究では,膜脂質の抽出と挿入に関与する新しいタンパク質のクラスが定義されています.
特定された脂質伝達メカニズムは,APOEがアストロサイトとニューロン間の脂質交換を媒介する脳の機能にとって重要である.

さらに関連する動画

06:59

Quantification of Atherosclerosis in Mice

Published on: June 12, 2019

38.4K

09:37

Optimized Negative Staining: a High-throughput Protocol for Examining Small and Asymmetric Protein Structure by Electron Microscopy

Published on: August 15, 2014

44.0K

関連する概念動画

01:39

Receptor-mediated Endocytosis

The Early Endosome: Endocytosis of Transferrin

3.5K

Essential proteins such as insulin or low-density lipoprotein (LDL) and micronutrients such as iron enter a eukaryotic cell through receptor-mediated endocytosis. Subsequently, the early endosomes fuse with the vesicles containing such receptor-ligand complexes and play a vital role in sorting the incoming ligands and receptors. While the ligands are either degraded inside the vesicle or released into the cytosol, their receptors are returned to the plasma membrane for further rounds of...

3.5K

01:19

Membrane Asymmetry Regulating Transporters

5.0K

Enzymes like flippase, floppase, and scramblase transfer phospholipids from one layer to another in the membrane, thereby affecting membrane asymmetry.
Flippase
Eukaryotic flippases are type-IV P-type ATPases or P4-ATPases belonging to P-type ATPase family proteins that are membrane-bound pumps involved in the ATP-mediated transport of ions and molecules across the membrane. Flippases flip specific phospholipids from the outer to the inner leaflet of a membrane. All P4-ATPases have one...

5.0K

01:45

Tail-anchoring of Proteins in the ER Membrane

3.2K

Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single transmembrane domain located approximately 30 amino acid residues upstream from the C-terminal end. As a result, the signal recognition particle (SRP) cannot guide a TA protein to the ER membrane for cotranslational insertion. Hence, they are integrated into the ER membrane post-translationally using their C-terminal end as the anchor. TA proteins...

3.2K

01:28

Maturation of Endosomes

4.4K

The early endosome containing internalized molecules matures through transformations in its location, morphology, intraluminal pH, and membrane protein composition. Together, these changes result in a more acidic late endosome that contains multiple intraluminal vesicles; therefore, the late endosome is also called a multivesicular body (MVB).
Changes in location
The maturing endosome moves along microtubules from the periphery of the cell towards the perinuclear region. This movement of the...

4.4K

01:19

Translocation of Proteins into the Mitochondria

4.3K

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,...