• Register
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.


Leaving Community

Are you sure you want to leave this community? Leaving the community will revoke any permissions you have been granted in this community.


Human alphaA- and alphaB-crystallins bind to Bax and Bcl-X(S) to sequester their translocation during staurosporine-induced apoptosis.

AlphaA- and alphaB-crystallins are distinct antiapoptotic regulators. Regarding the antiapoptotic mechanisms, we have recently demonstrated that alphaB-crystallin interacts with the procaspase-3 and partially processed procaspase-3 to repress caspase-3 activation. Here, we demonstrate that human alphaA- and alphaB-crystallins prevent staurosporine-induced apoptosis through interactions with members of the Bcl-2 family. Using GST pulldown assays and coimmunoprecipitations, we demonstrated that alpha-crystallins bind to Bax and Bcl-X(S) both in vitro and in vivo. Human alphaA- and alphaB-crystallins display similar affinity to both proapoptotic regulators, and so are true with their antiapoptotic ability tested in human lens epithelial cells, human retina pigment epithelial cells (ARPE-19) and rat embryonic myocardium cells (H9c2) under treatment of staurosporine, etoposide or sorbitol. Two prominent mutants, R116C in alphaA-crystallin and R120G, in alphaB-crystallin display much weaker affinity to Bax and Bcl-X(S). Through the interaction, alpha-crystallins prevent the translocation of Bax and Bcl-X(S) from cytosol into mitochondria during staurosporine-induced apoptosis. As a result, alpha-crystallins preserve the integrity of mitochondria, restrict release of cytochrome c, repress activation of caspase-3 and block degradation of PARP. Thus, our results demonstrate a novel antiapoptotic mechanism for alpha-crystallins.

Pubmed ID: 14752512


  • Mao YW
  • Liu JP
  • Xiang H
  • Li DW


Cell death and differentiation

Publication Data

May 19, 2004

Associated Grants

  • Agency: NEI NIH HHS, Id: EY11372
  • Agency: NEI NIH HHS, Id: R29 EY011372

Mesh Terms

  • Animals
  • Apoptosis
  • Caspases
  • Cells, Cultured
  • Cytochromes c
  • Cytosol
  • Epithelial Cells
  • Etoposide
  • Genes, bcl-2
  • Humans
  • Mitochondria
  • Mutation
  • Myocytes, Cardiac
  • Protein Transport
  • Proto-Oncogene Proteins c-bcl-2
  • Rats
  • Sorbitol
  • Staurosporine
  • alpha-Crystallin A Chain
  • alpha-Crystallin B Chain
  • bcl-2-Associated X Protein
  • bcl-X Protein