细胞膜表面核仁素的功能

Function of nucleolin localized on the cell surface

核仁素(又称C23)是真核细胞核仁中最主要的一种蛋白质,具有多种生物学功能,包括调控核糖体的生物合成与成熟、参与细胞增殖、生长、胚胎发生、胞质分裂、染色质复制、核仁的发生以及抗细胞凋亡作用。核仁素可作为多功能穿梭蛋白穿梭于细胞浆和细胞核之间,甚至表达在细胞膜上,如肿瘤细胞、免疫细胞以及血管内皮细胞等,这种细胞膜表面核仁素可充当多种蛋白分子、细菌、病毒的受体或共受体,并介导这些配体的生物学效应及病原微生物对宿主细胞的入侵。

Nucleolin is an abundant nucleolar phosphorylated protein which involves ribosome biogenesis and maturation,cell growth and proliferation,cytokinesis,replication,embryogenesis,nucleogenesis and anti-apoptosis.Recently,many studies show that nucleolin is a multifunctional shuttling protein present in nucleus,cytoplasm,and even on the surface of some types of cells,such as tumor cells,immune cells and endothelial cells,etc.The membrane-anchored nucleolin is considered as a cell surface receptor for various ligands including Midkin,Pleiotrophin,Lactoferrin,HIV,Enterohemorrhagic Escherichia coli et al.Many findings suggest that cell-surface nucleolin mediates the ligands-related biological response and invasion of pathogens to host cells.