Multimodal interaction with BCL-2 family proteins underlies the proapoptotic activity of PUMA BH3

Chem Biol. 2013 Jul 25;20(7):888-902. doi: 10.1016/j.chembiol.2013.06.007.


PUMA is a proapoptotic BCL-2 family member that drives the apoptotic response to a diversity of cellular insults. Deciphering the spectrum of PUMA interactions that confer its context-dependent proapoptotic properties remains a high priority goal. Here, we report the synthesis of PUMA SAHBs, structurally stabilized PUMA BH3 helices that, in addition to broadly targeting antiapoptotic proteins, directly bind to proapoptotic BAX. NMR, photocrosslinking, and biochemical analyses revealed that PUMA SAHBs engage an α1/α6 trigger site on BAX to initiate its functional activation. We further demonstrated that a cell-permeable PUMA SAHB analog induces apoptosis in neuroblastoma cells and, like expressed PUMA protein, engages BCL-2, MCL-1, and BAX. Thus, we find that PUMA BH3 is a dual antiapoptotic inhibitor and proapoptotic direct activator, and its mimetics may serve as effective pharmacologic triggers of apoptosis in resistant human cancers.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Apoptosis Regulatory Proteins / chemistry*
  • Apoptosis Regulatory Proteins / metabolism*
  • Apoptosis*
  • Caspase 3 / metabolism
  • Caspase 7 / metabolism
  • Enzyme Activation
  • HEK293 Cells
  • Humans
  • Mice
  • Models, Molecular
  • Molecular Sequence Data
  • Porosity
  • Protein Structure, Tertiary
  • Proteomics
  • Proto-Oncogene Proteins c-bcl-2 / chemistry*
  • Proto-Oncogene Proteins c-bcl-2 / metabolism*
  • Substrate Specificity
  • bcl-2-Associated X Protein / metabolism


  • Apoptosis Regulatory Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • bcl-2-Associated X Protein
  • Caspase 3
  • Caspase 7