Identification of DeltaNp63alpha protein interactions by mass spectrometry

J Proteome Res. 2010 Apr 5;9(4):2042-8. doi: 10.1021/pr9011156.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Cluster Analysis
  • Databases, Protein
  • Heterogeneous-Nuclear Ribonucleoproteins / chemistry
  • Heterogeneous-Nuclear Ribonucleoproteins / metabolism
  • Humans
  • Protein Interaction Mapping / methods*
  • Protein Isoforms
  • Proteins / chemistry
  • Proteins / metabolism
  • RNA-Binding Protein FUS / chemistry
  • RNA-Binding Protein FUS / metabolism
  • Tandem Mass Spectrometry / methods*
  • Trans-Activators / chemistry
  • Trans-Activators / metabolism*
  • Transcription Factors
  • Tumor Suppressor Proteins / chemistry
  • Tumor Suppressor Proteins / metabolism*

Substances

  • Heterogeneous-Nuclear Ribonucleoproteins
  • Protein Isoforms
  • Proteins
  • RNA-Binding Protein FUS
  • TP63 protein, human
  • Trans-Activators
  • Transcription Factors
  • Tumor Suppressor Proteins