Nucleolin (NCL) (NCL)

Nucleolin is a multifunctional phosphoprotein primarily located in the nucleolus, where it regulates ribosome biogenesis and chromatin structure (UniProt P19338) [1]. In many cancer cells and actively dividing endothelial cells, nucleolin is translocated to the cell surface, where it acts as a receptor for various ligands involved in cell proliferation, adhesion, and angiogenesis (Koutsioumpa & Papadimitriou, 2014) [2]. This membrane-bound form of nucleolin is a promising therapeutic target because its expression is highly specific to pathological states, particularly in the tumor microenvironment (Bates et al., 2009) [3]. Drugs targeting membrane nucleolin, such as the DNA aptamer AS1411 or the pseudopeptide N6L, aim to disrupt its interaction with growth factors and signaling molecules, thereby inducing apoptosis and inhibiting tumor growth (Soundararajan et al., 2009; Destouches et al., 2011) [4, 5]. Additionally, membrane nucleolin facilitates the internalization of certain viruses and toxins, making it a target for antiviral and antitoxin strategies (Tayyari et al., 2011) [6].

Other names

C23Protein C23Surface nucleolinCell-surface nucleolin

Binding to surface nucleolin leads to the inhibition of cell proliferation, induction of apoptosis, and blockade of angiogenesis by interfering with ligand-receptor interactions and downstream signaling pathways.