NPM1
Nucleophosmin (NPM), also known as nucleolar phosphoprotein B23 or numatrin, is a protein that in humans is encoded by the NPM1 gene.
Function
NPM1 is associated with nucleolar ribonucleoprotein structures and bind single-stranded and double-stranded nucleic acids, but it binds preferentially G-Quadruplex forming nucleic acids. It is involved in the biogenesis of ribosomes and may assist small basic proteins in their transport to the nucleolus. Its regulation through SUMOylation (by SENP3 and SENP5) is another facet of the proteins's regulation and cellular functions.
It is located in the nucleolus, but it can be translocated to the nucleoplasm in case of serum starvation or treatment with anticancer drugs. The protein is phosphorylated.
Nucleophosmin has multiple functions:
Histone chaperons
Ribosome biogenesis and transport
Genomic stability and DNA repair
Endoribonuclease activity
Centrosome duplication during cell cycle
Regulation of ARF-p53 tumor suppressor pathway
RNA helix destabilizing activity