GPRASP2を介したエンドサイトーシスの亢進はHSCの忠実性を維持する
bioRxiv : the preprint server for biology
|February 23, 2026
まとめ
静止状態の造血幹細胞(HSC)は、自己複製を維持し枯渇を防ぐために、GPRASP2によって調節されるエンドサイトーシスの亢進を利用する。このプロセスはシグナル伝達を制限し、幹細胞機能を保証する。
科学分野:
- 細胞生物学
- 造血
- 幹細胞生物学
背景:
- エンドリソソーム輸送は、細胞の恒常性およびシグナル伝達調節に不可欠である。
- 造血幹細胞(HSC)の維持には、静止状態と活性化状態のバランスが必要である。
- HSCの静止状態および機能におけるエンドサイトーシス経路の役割は、完全には理解されていない。
研究 の 目的:
- 静止状態のHSC自己複製の維持におけるエンドサイトーシスの役割を調査する。
- HSC機能のエンドサイトーシス調節に関与する特定のタンパク質を同定する。
- エンドサイトーシスがHSCシグナル伝達と増殖に影響を与えるメカニズムを解明する。
主な方法:
- 静止状態のHSCにおけるエンドサイトーシス活性の分析。
- HSCのエンドサイトーシスおよび機能におけるGPRASP2の役割の調査。
- GPRASP2を介したエンドサイトーシスの破壊後のHSC増殖およびシグナル伝達の評価。
主要な成果:
- 静止状態のHSCは、自己複製に不可欠なエンドサイトーシスの亢進を示す。
- GPRASP2はHSCにおけるエンドサイトーシスを媒介する主要なタンパク質として同定された。
- GPRASP2を介したエンドサイトーシスの破壊は、HSCの増殖とシグナル伝達の亢進につながる。
結論:
- GPRASP2によって媒介されるエンドサイトーシスの亢進は、HSCの静止状態および自己複製の維持に不可欠である。
- エンドサイトーシスは、受容体の内化によるシグナル伝達の減衰メカニズムとして機能し、HSCの枯渇を防ぐ。
- エンドサイトーシス経路を標的とすることは、HSC機能を管理し、加齢に伴う幹細胞機能不全を防ぐための戦略を提供する可能性がある。
関連する概念動画
ER Retrieval Pathway
4.9K
In the secretory pathway, vesicles transport proteins from one cellular compartment to another in forward transport to deliver the protein to its correct location. Occasionally, misfolded proteins and incorrect proteins escape their original compartments, and a retrieval pathway is used to return the escaped proteins to their original compartment.
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
4.9K
Recycling Endosomes and Transcytosis
3.7K
The recycling endosome, also known as the endosomal recycling compartment (ERC), is a part of the slow-recycling process of the endocytic pathway. Molecules internalized through receptor-mediated endocytosis are either degraded in the lysosomes or are recycled to the plasma membrane through the fast- or slow-recycling route.
The recycling endosome is not a single organelle but an extensively tubulated network of recycling pathways. It functions in storing molecules or transporting them across...
The recycling endosome is not a single organelle but an extensively tubulated network of recycling pathways. It functions in storing molecules or transporting them across...
3.7K
Export of Misfolded Proteins out of the ER
5.3K
After folding, the ER assesses the quality of secretory and membrane proteins. The correctly folded proteins are cleared by the calnexin cycle for transport to their final destination, while misfolded proteins are held back in the ER lumen. The ER chaperones attempt to unfold and refold the misfolded proteins but sometimes fail to achieve the correct native conformation. Such terminally misfolded proteins are then exported to the cytosol by ER-associated degradation or ERAD pathway for...
5.3K
Vesicular Tubular Clusters
3.3K
After budding out from the ER membrane, some COPII vesicles lose their coat and fuse with one another to form larger vesicles and interconnected tubules called vesicular tubular clusters or VTCs. These clusters constitute a compartment at the ER-Golgi interface known as ERGIC (Endoplasmic Reticulum Golgi Intermediate Compartment). The ERGIC is a mobile membrane-bound cargo transport system that sorts proteins secreted from ER and delivers them to the Golgi.
With the help of motor proteins such...
With the help of motor proteins such...
3.3K
Coat Assembly and GTPases
4.5K
Vesicles incorporate different coat protein subunits in different cell locations, which changes the properties of the coat, such as the shape and geometry of the transport vesicles. Thus, vesicle coat proteins also play a significant role in cargo selection.
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
4.5K
Regulation of Nuclear Protein Sorting
3.4K
Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
3.4K


