NMR structure of Npm1_c70
[NPM_HUMAN] Note=A chromosomal aberration involving NPM1 is found in a form of non-Hodgkin lymphoma. Translocation t(2;5)(p23;q35) with ALK. The resulting chimeric NPM1-ALK protein homodimerize and the kinase becomes constitutively activated. Note=A chromosomal aberration involving NPM1 is found in a form of acute promyelocytic leukemia. Translocation t(5;17)(q32;q11) with RARA. Note=A chromosomal aberration involving NPM1 is a cause of myelodysplastic syndrome (MDS). Translocation t(3;5)(q25.1;q34) with MLF1. Note=Defects in NPM1 are associated with acute myelogenous leukemia (AML). Mutations in exon 12 affecting the C-terminus of the protein are associated with an aberrant cytoplasmic location.
[NPM_HUMAN] Involved in diverse cellular processes such as ribosome biogenesis, centrosome duplication, protein chaperoning, histone assembly, cell proliferation, and regulation of tumor suppressors p53/TP53 and ARF. Binds ribosome presumably to drive ribosome nuclear export. Associated with nucleolar ribonucleoprotein structures and bind single-stranded nucleic acids. Acts as a chaperonin for the core histones H3, H2B and H4. Stimulates APEX1 endonuclease activity on apurinic/apyrimidinic (AP) double-stranded DNA but inhibits APEX1 endonuclease activity on AP single-stranded RNA. May exert a control of APEX1 endonuclease activity within nucleoli devoted to repair AP on rDNA and the removal of oxidized rRNA molecules. In concert with BRCA2, regulates centrosome duplication. Regulates centriole duplication: phosphorylation by PLK2 is able to trigger centriole replication.      
Publication Abstract from PubMed
Nucleophosmin (NPM1) is a nucleocytoplasmic shuttling protein, mainly localized at nucleoli, that plays a key role in several cellular functions, including ribosome maturation and export, centrosome duplication, and response to stress stimuli. More than 50 mutations at the terminal exon of the NPM1 gene have been identified so far in acute myeloid leukemia; the mutated proteins are aberrantly and stably localized in the cytoplasm due to high destabilization of the NPM1 C-terminal domain and the appearance of a new nuclear export signal. We have shown previously that the 70-residue NPM1 C-terminal domain (NPM1-C70) is able to bind with high affinity a specific region at the c-MYC gene promoter characterized by parallel G-quadruplex structure. Here we present the solution structure of the NPM1-C70 domain and NMR analysis of its interaction with a c-MYC-derived G-quadruplex. These data were used to calculate an experimentally restrained molecular docking model for the complex. The NPM1-C70 terminal three-helix bundle binds the G-quadruplex DNA at the interface between helices H1 and H2 through electrostatic interactions with the G-quadruplex phosphate backbone. Furthermore, we show that the 17-residue lysine-rich sequence at the N terminus of the three-helix bundle is disordered and, although necessary, does not participate directly in the contact surface in the complex.
Structure of Nucleophosmin DNA-binding Domain and Analysis of Its Complex with a G-quadruplex Sequence from the c-MYC Promoter.,Gallo A, Lo Sterzo C, Mori M, Di Matteo A, Bertini I, Banci L, Brunori M, Federici L J Biol Chem. 2012 Aug 3;287(32):26539-48. Epub 2012 Jun 15. PMID:22707729
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.