title: Isoform-specific interactions of the von Hippel-Lindau tumor suppressor protein.
abstract: Deregulation of the von Hippel-Lindau tumor suppressor protein (pVHL) is considered one of the main causes for malignant renal clear-cell carcinoma (ccRCC) insurgence. In human, pVHL exists in two isoforms, pVHL19 and pVHL30 respectively, displaying comparable tumor suppressor abilities. Mutations of the p53 tumor suppressor gene have been also correlated with ccRCC insurgence and ineffectiveness of treatment. A recent proteomic analysis linked full length pVHL30 with p53 pathway regulation through complex formation with the p14ARF oncosuppressor. The alternatively spliced pVHL19, missing the first 53 residues, lacks this interaction and suggests an asymmetric function of the two pVHL isoforms. Here, we present an integrative bioinformatics and experimental characterization of the pVHL oncosuppressor isoforms. Predictions of the pVHL30 N-terminus three-dimensional structure suggest that it may exist as an ensemble of structured and disordered forms. The results were used to guide Yeast two hybrid experiments to highlight isoform-specific binding properties. We observed that the physical pVHL/p14ARF interaction is specifically mediated by the 53 residue long pVHL30 N-terminal region, suggesting that this N-terminus acts as a further pVHL interaction interface. Of note, we also observed that the shorter pVHL19 isoform shows an unexpected high tendency to form homodimers, suggesting an additional isoform-specific binding specialization.
authors.affiliation: Department of Biomedical Sciences, University of Padova.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Minervini
authors.affiliation: Department of Biology, University of Padova.
authors.forename: Gabriella M
authors.initials: GM
authors.lastname: Mazzotta
authors.affiliation: Department of Biomedical Sciences, University of Padova.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Masiero
authors.affiliation: Department of Biology, University of Padova.
authors.forename: Elena
authors.initials: E
authors.lastname: Sartori
authors.affiliation: Department of Biology, University of Padova.
authors.forename: Samantha
authors.initials: S
authors.lastname: Corrà
authors.affiliation: Department of Biomedical Sciences, University of Padova.
authors.forename: Emilio
authors.initials: E
authors.lastname: Potenza
authors.affiliation: Department of Biology, University of Padova.
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Costa
authors.affiliation: 1] Department of Biomedical Sciences, University of Padova [2] CNR Institute of Neuroscience, Padova, Italy.
authors.forename: Silvio C E
authors.initials: SC
authors.lastname: Tosatto
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D003198:Computer Simulation; D006801:Humans; D008954:Models, Biological; D008956:Models, Chemical; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D025941:Protein Interaction Mapping / Q000379:methods*; D020033:Protein Isoforms; D020539:Sequence Analysis, Protein / Q000379:methods*; D013329:Structure-Activity Relationship; D051794:Von Hippel-Lindau Tumor Suppressor Protein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D020033:Protein Isoforms; D051794:Von Hippel-Lindau Tumor Suppressor Protein; C497446:VHL protein, human