Nucleolin is a multifunctional phosphoprotein ubiquitously distributed in the nucleolus, nucleus and cytoplasm of the cell. Nucleolin has a bipartite nuclear localization signal sequence and is conserved across the species. Nucleolin levels are expressed in abundance in exponentially growing cells and it regulates various aspects of DNA and RNA metabolism, chromatin structure, rDNA transcription, rRNA maturation, cytokinesis, nucleogenesis, cell proliferation and growth (1). Studies carried out to investigate the role of nucleolin in proliferating human cells using siRNA and subsequent detection of nucleolin levels by anti-nucleolin antibodies demonstrated the importance of nucleolin in cell proliferation and regulation (2).
Emerging evidence suggests that nucleolin is also expressed on the cell surface where it serves as a binding protein for variety of ligands implicated in cell proliferation, differentiation, adhesion, mitogenesis and angiogenesis as detected by anti-nucleolin antibodies (3). Considerable progress has been made in recent years with the identification of new nucleolin binding proteins that may mediate these many nucleolin-dependent functions as a cell surface receptor, where it acts as a shuttling protein between cytoplasm and nucleus, and thus can even provide a mechanism for extracellular regulation of nuclear events. Exploration of the regulation of this multifaceted protein in a remarkable number of diverse functions is challenging (4).
Novus Biologicals offers Nucleolin reagents for your research needs including:
