Application of an integrated physical and functional screening approach to identify inhibitors of the Wnt pathway

Mol Syst Biol. 2009:5:315. doi: 10.1038/msb.2009.72. Epub 2009 Oct 13.

Abstract

Large-scale proteomic approaches have been used to study signaling pathways. However, identification of biologically relevant hits from a single screen remains challenging due to limitations inherent in each individual approach. To overcome these limitations, we implemented an integrated, multi-dimensional approach and used it to identify Wnt pathway modulators. The LUMIER protein-protein interaction mapping method was used in conjunction with two functional screens that examined the effect of overexpression and siRNA-mediated gene knockdown on Wnt signaling. Meta-analysis of the three data sets yielded a combined pathway score (CPS) for each tested component, a value reflecting the likelihood that an individual protein is a Wnt pathway regulator. We characterized the role of two proteins with high CPSs, Ube2m and Nkd1. We show that Ube2m interacts with and modulates beta-catenin stability, and that the antagonistic effect of Nkd1 on Wnt signaling requires interaction with Axin, itself a negative pathway regulator. Thus, integrated physical and functional mapping in mammalian cells can identify signaling components with high confidence and provides unanticipated insights into pathway regulators.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Animals
  • Axin Protein
  • Calcium-Binding Proteins
  • Carrier Proteins / metabolism
  • Cell Line
  • High-Throughput Screening Assays / methods*
  • Humans
  • Mice
  • Models, Biological
  • Protein Binding
  • Protein Interaction Mapping
  • RNA Interference
  • Repressor Proteins / metabolism
  • Signal Transduction*
  • Ubiquitin-Conjugating Enzymes / metabolism
  • Wnt Proteins / antagonists & inhibitors*

Substances

  • Adaptor Proteins, Signal Transducing
  • Axin Protein
  • Calcium-Binding Proteins
  • Carrier Proteins
  • NKD1 protein, human
  • Repressor Proteins
  • Wnt Proteins
  • Ubiquitin-Conjugating Enzymes
  • UBE2M protein, human