title: Destabilisation, aggregation, toxicity and cytosolic mislocalisation of nucleophosmin regions associated with acute myeloid leukemia.
abstract: Nucleophosmin (NPM1) is a multifunctional protein that is implicated in the pathogenesis of several human malignancies. To gain insight into the role of isolated fragments of NPM1 in its biological activities, we dissected the C-terminal domain (CTD) into its helical fragments. Here we focus the attention on the third helix of the NPM1-CTD in its wild-type (H3 wt) and AML-mutated (H3 mutA and H3 mutE) sequences. Conformational studies, by means of CD and NMR spectroscopies, showed that the H3 wt peptide was partially endowed with an α-helical structure, but the AML-sequences exhibited a lower content of this conformation, particularly the H3 mutA peptide. Thioflavin T assays showed that the H3 mutE and the H3 mutA peptides displayed a significant aggregation propensity that was confirmed by CD and DLS assays. In addition, we found that the H3 mutE and H3 mutA peptides, unlike the H3 wt, were moderately and highly toxic, respectively, when exposed to human neuroblastoma cells. Cellular localization experiments confirmed that the mutated sequences hamper their nucleolar accumulation, and more importantly, that the helical conformation of the H3 region is crucial for such a localization.
authors: Department of Pharmacy, CIRPEB: Centro Interuniversitario di Ricerca sui Peptidi Bioattivi-University of Naples "Federico II", DFM-Scarl, 80134, Naples, Italy.|Permanent address: Center for Advanced Biomaterials for Health Care@CRIB Istituto Italiano di Tecnologia, 80125, Napoli, Italy.
authors: Pasqualina Liana
authors: PL
authors: Scognamiglio
authors: Department of Pharmacy, CIRPEB: Centro Interuniversitario di Ricerca sui Peptidi Bioattivi-University of Naples "Federico II", DFM-Scarl, 80134, Naples, Italy.
authors: Concetta
authors: C
authors: Di Natale
authors: Institute of Biostructures and Bioimaging - CNR, 80134, Naples, Italy.
authors: Marilisa
authors: M
authors: Leone
authors: Section of Biochemistry, Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134, Florence, Italy.
authors: Roberta
authors: R
authors: Cascella
authors: Section of Biochemistry, Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134, Florence, Italy.
authors: Cristina
authors: C
authors: Cecchi
authors: Laboratory of Molecular Biology and DNA repair, Department of Medical and Biological Sciences, University of Udine, 33100, Udine, Italy.|Permanent address: Department of Clinical Molecular Biology, University of Oslo and Akershus University Hospital, Nordbyhagen, 1474, Norway.
authors: Lisa
authors: L
authors: Lirussi
authors: Laboratory of Molecular Biology and DNA repair, Department of Medical and Biological Sciences, University of Udine, 33100, Udine, Italy.
authors: Giulia
authors: G
authors: Antoniali
authors: Department of Pharmacy, CIRPEB: Centro Interuniversitario di Ricerca sui Peptidi Bioattivi-University of Naples "Federico II", DFM-Scarl, 80134, Naples, Italy.
authors: Domenico
authors: D
authors: Riccardi
authors: Department of Pharmacy, CIRPEB: Centro Interuniversitario di Ricerca sui Peptidi Bioattivi-University of Naples "Federico II", DFM-Scarl, 80134, Naples, Italy.
authors: Giancarlo
authors: G
authors: Morelli
authors: Laboratory of Molecular Biology and DNA repair, Department of Medical and Biological Sciences, University of Udine, 33100, Udine, Italy.
authors: Gianluca
authors: G
authors: Tell
authors: Section of Biochemistry, Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134, Florence, Italy.
authors: Fabrizio
authors: F
authors: Chiti
authors: Department of Pharmacy, CIRPEB: Centro Interuniversitario di Ricerca sui Peptidi Bioattivi-University of Naples "Federico II", DFM-Scarl, 80134, Naples, Italy.
authors: Daniela
authors: D
authors: Marasco
mesh_terms: D017209:Apoptosis; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism*; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D000090243:Nucleophosmin; D010446:Peptide Fragments; D066263:Protein Aggregation, Pathological; D011487:Protein Conformation; D055550:Protein Stability; D021381:Protein Transport
chemical_list: C000716967:NPM1 protein, human; D009687:Nuclear Proteins; D010446:Peptide Fragments; D000090243:Nucleophosmin
keywords: AML; CD spectroscopy; aggregation phenomena; helical peptides