The nucleoplasmin family includes nucleophosmin, nucleoplasmin and nucleoplasmin-like proteins. Nucleophosmin (also known as NPM1/B23) is a multifunctional protein that is involved in a number of cellular activities, such as ribosome maturatation and export, centrosome duplication, and response to stress stimuli []. Nucleoplasmin (NPM2) is a histone chaperone for histones H2A-H2B and is highly expressed in the oocyte and through the early stages of embryogenesis [].Mutations of the NPM1 gene has been linked to acute myeloid leukemia [].
This domain, approximately 50 residues in length, is mainly found in C-terminal region of nucleophosmin from animals []. Nucleophosmin (also known as NPM1/B23) is a multifunctional protein that is involved in a number of cellular activities, such as ribosome maturatation and export, centrosome duplication, and response to stress stimuli []. Although it shuttles rapidly between the nucleus and the cytoplasm, a large fraction of NPM1/B23 resides in the nucleoli []. Mutations of the NPM1 gene has been linked to acute myeloid leukemia []. This domain has a three-helix bundle which binds the G-quadruplex DNA at the interface between helices H1 and H2 through electrostatic interactions with the G-quadruplex phosphate backbone [, ].