Nucleophosmin C-terminal leukemia-associated domain interacts with G-rich quadruplex forming DNA.
Nucleophosmin (NPM1) is a nucleocytoplasmic shuttling phosphoprotein, mainly localized at nucleoli, that plays a key role in ribogenesis, centrosome duplication, and response to stress stimuli. Mutations at the C-terminal domain of NPM1 are the most frequent genetic lesion in acute myeloid leukemia and cause the aberrant and stable translocation of the protein in the cytoplasm. The NPM1 C-terminal domain was previously shown to bind nucleic acids. Here we further investigate the DNA binding properties of the NPM1 C-terminal domain both at the protein and nucleic acid levels; we investigate the domain boundaries and identify key residues for high affinity recognition. Furthermore, we demonstrate that the NPM1 C-terminal domain has a preference for G-quadruplex forming DNA regions and induces the formation of G-quadruplex structures in vitro. Finally we show that a specific sequence found at the SOD2 gene promoter, which was previously shown to be a target of NPM1 in vivo, is indeed folded as a G-quadruplex in vitro under physiological conditions. Our data extend considerably present knowledge on the DNA binding properties of NPM1 and suggest a general role in the transcription of genes characterized by the presence of G-quadruplex forming regions at their promoters.
Federici
Luca
L
Department of Biomedical Sciences, University of Chieti G D'Annunzio, CeSI Center of Excellence on Aging, 66013 Chieti, Italy. lfederici@unich.it
Arcovito
Alessandro
A
Scaglione
Giovanni L
GL
Scaloni
Flavio
F
Lo Sterzo
Carlo
C
Di Matteo
Adele
A
Falini
Brunangelo
B
Giardina
Bruno
B
Brunori
Maurizio
M
D000595:Amino Acid Sequence; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D054856:G-Quadruplexes; D006801:Humans; D007700:Kinetics; D015470:Leukemia, Myeloid, Acute / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000090243:Nucleophosmin; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
C000716967:NPM1 protein, human; D009687:Nuclear Proteins; D000090243:Nucleophosmin; D004247:DNA