BAF53 forms distinct nuclear complexes and functions as a critical c-Myc-interacting nuclear cofactor for oncogenic transformation

Mol Cell Biol. 2002 Mar;22(5):1307-16. doi: 10.1128/MCB.22.5.1307-1316.2002.


The c-Myc oncoprotein functions as a transcription factor that can transform normal cells into tumor cells, as well as playing a direct role in normal cell proliferation. The c-Myc protein transactivates cellular promoters by recruiting nuclear cofactors to chromosomal sites through an N-terminal transactivation domain. We have previously reported the identification and functional characterization of four different c-Myc cofactors: TRRAP, hGCN5, TIP49, and TIP48. Here we present the identification and characterization of the actin-related protein BAF53 as a c-Myc-interacting nuclear cofactor that forms distinct nuclear complexes. In addition to the human SWI/SNF-related BAF complex, BAF53 forms a complex with TIP49 and TIP48 and a separate biochemically distinct complex containing TRRAP and a histone acetyltransferase which does not contain TIP60. Using deletion mutants of BAF53, we show that BAF53 is critical for c-Myc oncogenic activity. Our results indicate that BAF53 plays a functional role in c-Myc-interacting nuclear complexes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • ATPases Associated with Diverse Cellular Activities
  • Acetyltransferases / metabolism
  • Actins / genetics
  • Actins / metabolism*
  • Adaptor Proteins, Signal Transducing
  • Adenosine Triphosphatases / metabolism
  • Carrier Proteins / metabolism
  • Cell Transformation, Neoplastic / metabolism*
  • Chromosomal Proteins, Non-Histone*
  • DNA Helicases / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Gene Deletion
  • HeLa Cells
  • Histone Acetyltransferases
  • Histones / analysis
  • Humans
  • Mutation
  • Nuclear Proteins / metabolism*
  • Nucleosomes / chemistry
  • Protein Binding
  • Proto-Oncogene Proteins c-myc / metabolism*
  • Saccharomyces cerevisiae Proteins*
  • Transcription Factors / metabolism*


  • ACTL6A protein, human
  • Actins
  • Adaptor Proteins, Signal Transducing
  • Carrier Proteins
  • Chromosomal Proteins, Non-Histone
  • DNA-Binding Proteins
  • Histones
  • Nuclear Proteins
  • Nucleosomes
  • Proto-Oncogene Proteins c-myc
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • transformation-transcription domain-associated protein
  • Acetyltransferases
  • Histone Acetyltransferases
  • Adenosine Triphosphatases
  • ATPases Associated with Diverse Cellular Activities
  • DNA Helicases
  • RUVBL1 protein, human
  • RUVBL2 protein, human