Apoptosis

, Volume 6, Issue 5, pp 319–330

Underphosphorylated BAD interacts with diverse antiapoptotic Bcl-2 family proteins to regulate apoptosis

Authors

  • J. Bae
    • Division of Reproductive Biology, Department of Gynecology and ObstetricsStanford University School of Medicine
  • S. Y. Hsu
    • Division of Reproductive Biology, Department of Gynecology and ObstetricsStanford University School of Medicine
  • C. P. Leo
    • Division of Reproductive Biology, Department of Gynecology and ObstetricsStanford University School of Medicine
  • K. Zell
    • Division of Reproductive Biology, Department of Gynecology and ObstetricsStanford University School of Medicine
  • A. J. W. Hsueh
    • Division of Reproductive Biology, Department of Gynecology and ObstetricsStanford University School of Medicine
Article

DOI: 10.1023/A:1011319901057

Cite this article as:
Bae, J., Hsu, S.Y., Leo, C.P. et al. Apoptosis (2001) 6: 319. doi:10.1023/A:1011319901057

Abstract

Survival factors activate kinases which, in turn, phosphorylate the proapoptotic Bcl-xl/Bcl-2-associated death promoter homolog (BAD) protein at key serine residues. Phosphorylated BAD interacts with 14-3-3 proteins, and overexpression of 14-3-3 attenuates BAD-mediated apoptosis. Although BAD is known to interact with Bcl-2, Bcl-w, and Bcl-xL, the exact relationship between BAD and anti- or proapoptotic Bcl-2 proteins has not been analyzed systematically. Using the yeast two-hybrid protein interaction assay, we found that BAD interacted negligibly with proapoptotic Bcl-2 proteins. Even though wild type BAD only interacted with selected numbers of antiapoptotic proteins, underphosphorylated mutant BAD interacted with all antiapoptotic Bcl-2 proteins tested (Bcl-2, Bcl-w, Bcl-xL, Bfl-1/A1, Mcl-1, Ced-9, and BHRF-1). Using nonphosphorylated recombinant BAD expressed in bacteria, direct interactions between BAD and diverse antiapoptotic Bcl-2 members were also observed. Furthermore, apoptosis induced by BAD was blocked by coexpression with Bcl-2, Bcl-w, and Bfl-1. Comparison of BAD orthologs from zebrafish to human indicated the conservation of a 14-3-3 binding site and the BH3 domain during evolution. Thus, highly conserved BAD interacts with diverse antiapoptotic Bcl-2 members to regulate apoptosis.

apoptosisBcl-2BADphosphorylationprogrammed cell deathyeast two-hybrid

Copyright information

© Kluwer Academic Publishers 2001