Bfk: a novel weakly proapoptotic member of the Bcl-2 protein family with a BH3 and a BH2 region

Cell Death Differ. 2003 Feb;10(2):185-92. doi: 10.1038/sj.cdd.4401204.


Proteins of the Bcl-2 family are critical regulators of apoptosis. Proapoptotic members, like Bax, contain three of the four Bcl-2 homology regions (BH1-3), while BH3-only proteins, like Bim, possess only the short BH3 motif. Database searches revealed Bfk, an unusual novel member of the Bcl-2 family that contains a BH2 and BH3 region but not BH1 or BH4. Bfk is thus most closely related to Bcl-G(L). It lacks a C-terminal membrane anchor and is cytosolic. Enforced expression of Bfk weakly promoted apoptosis and antagonized Bcl-2's prosurvival function. Like Bcl-G(L), Bfk did not bind to any Bcl-2 family members, even though its BH3 motif can mediate association with prosurvival proteins. Low amounts of Bfk were found in stomach, ovary, bone marrow and spleen, but its level in the mammary gland rose markedly during pregnancy, suggesting that Bfk may play a role in mammary development.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Apoptosis*
  • Conserved Sequence
  • Cytosol / chemistry
  • Female
  • Humans
  • Male
  • Mice
  • Molecular Sequence Data
  • NIH 3T3 Cells
  • Pregnancy
  • Proto-Oncogene Proteins c-bcl-2 / chemistry*
  • Sequence Homology, Amino Acid
  • Tissue Distribution


  • BCL2L15 protein, human
  • Bcl2l15 protein, mouse
  • Proto-Oncogene Proteins c-bcl-2