QUICK identification and SPR validation of signal transducers and activators of transcription 3 (Stat3) interacting proteins

J Proteomics. 2012 Jan 4;75(3):1055-66. doi: 10.1016/j.jprot.2011.10.020. Epub 2011 Oct 30.


Signal transducers and activators of transcription 3 (Stat3) has been reported to be involved in the pathogenesis of various human diseases and is constitutively active in human multiple myeloma (MM) U266 cells. The Stat3-regulated mechanisms involved in these processes, however, are not fully defined. To further understand the regulation of Stat3 activity, we performed a systematic proteomic analysis of Stat3 interacting proteins in U266 cells. This analysis, termed quantitative immunoprecipitation combined with knockdown (QUICK), combines RNAi, stable isotope labeling with amino acids in cell culture (SILAC), immunoprecipitation, and quantitative MS. As a result, quantitative mass spectrometry analysis allowed us to distinguish specific Stat3 interacting proteins from background proteins and led to the identification of a total of 38 proteins. Three Stat3 interacting proteins - 14-3-3ζ, PRKCB and Hsp90 - were further confirmed by reciprocal co-immunoprecipitations and surface plasmon resonance (SPR) analysis. Our results therefore not only uncover a number of Stat3 interacting proteins that possess a variety of cellular functions, but also provide new insight into the mechanisms that regulate Stat3 activity and function in MM cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism*
  • Cell Line, Tumor
  • Humans
  • Multiple Myeloma / metabolism*
  • Neoplasm Proteins / metabolism*
  • Proteomics / methods
  • STAT3 Transcription Factor / metabolism*
  • Surface Plasmon Resonance


  • Adaptor Proteins, Signal Transducing
  • Neoplasm Proteins
  • STAT3 Transcription Factor
  • STAT3 protein, human