title: Identification of DeltaNp63alpha protein interactions by mass spectrometry.
abstract: p63, a transcription factor related to the p53 tumor suppressor, plays a key role in epidermal differentiation and limb development. The gene has two distinct promoters that allow the formation of proteins that either contain (TA) or lack (DeltaN) a transactivation domain. DeltaNp63alpha is the most widely expressed isoform, at all stages of development and in adult tissues. It supports the regenerative capacity of basal keratinocytes and its upregulation is a hallmark of human squamous carcinomas. To get insight into the complex biology of DeltaNp63alpha, we set out to identify DeltaNp63alpha interacting proteins by co-immunoprecipitation in mammalian cells and mass spectrometry analysis. A total of 49 potential DeltaNp63alpha binding proteins, including several heterogeneous ribonucleoproteins (hnRNPs), were identified. Integration of the proteomic data with a Human Coexpression Network highlighted 5 putative p63 protein interactors whose expression is significantly comodulated with p63: hnRNPA/B, hnRNPK, hnRNPQ, FUS/TLS and Keratin 5. hnRNPA/B was already described as a p63 partner, but the others were novel. Interaction of DeltaNp63alpha with hnRNPQ, hnRNPK and FUS/TLS was confirmed by reciprocal co-immunoprecipitations in human keratinocytes. The finding that DeltaNp63alpha exists in complexes with several RNA-binding proteins lays the premises for the analysis of the role of DeltaNp63alpha in mRNA metabolism and transport.
authors.affiliation: Dipartimento di Chimica Organica e Biologica, Universita Federico II, Napoli, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Amoresano
authors.forename: Antonella
authors.initials: A
authors.lastname: Di Costanzo
authors.forename: Gabriella
authors.initials: G
authors.lastname: Leo
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Di Cunto
authors.forename: Girolama
authors.initials: G
authors.lastname: La Mantia
authors.forename: Luisa
authors.initials: L
authors.lastname: Guerrini
authors.forename: Viola
authors.initials: V
authors.lastname: Calabrò
mesh_terms: D045744:Cell Line, Tumor; D016000:Cluster Analysis; D030562:Databases, Protein; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D025941:Protein Interaction Mapping / Q000379:methods*; D020033:Protein Isoforms; D011506:Proteins / Q000737:chemistry / Q000378:metabolism; D034702:RNA-Binding Protein FUS / Q000737:chemistry / Q000378:metabolism; D053719:Tandem Mass Spectrometry / Q000379:methods*; D015534:Trans-Activators / Q000737:chemistry / Q000378:metabolism*; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D034441:Heterogeneous-Nuclear Ribonucleoproteins; D020033:Protein Isoforms; D011506:Proteins; D034702:RNA-Binding Protein FUS; C115051:TP63 protein, human; D015534:Trans-Activators; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins