Transforming growth factor beta 1 induces apoptosis through cleavage of BAD in a Smad3-dependent mechanism in FaO hepatoma cells.

نویسندگان

  • Byung-Chul Kim
  • Mizuko Mamura
  • Kyeong Sook Choi
  • Bruno Calabretta
  • Seong-Jin Kim
چکیده

Transforming growth factor beta (TGF-beta) induces apoptosis in a variety of cells. We have previously shown that TGF-beta 1 rapidly induces apoptosis in the FaO rat hepatoma cell line. We have now studied the effect of TGF-beta 1 on the expression of different members of the Bcl-2 family in these cells. We observed no detectable changes in the steady-state levels of Bcl-2, Bcl-X(L), and Bax. However, TGF-beta 1 induced caspase-dependent cleavage of BAD at its N terminus to generate a 15-kDa truncated protein. Overexpression of the 15-kDa truncated BAD protein enhanced TGF-beta 1-induced apoptosis, whereas a mutant BAD resistant to caspase 3 cleavage blocked TGF-beta 1-induced apoptosis. Overexpression of Smad3 dramatically enhanced TGF-beta 1-induced cleavage of BAD and apoptosis, whereas antisense Smad3 blocked TGF-beta 1-induced apoptosis and BAD cleavage. These results suggest that TGF-beta 1 induces apoptosis through the cleavage of BAD in a Smad3-dependent mechanism.

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عنوان ژورنال:
  • Molecular and cellular biology

دوره 22 5  شماره 

صفحات  -

تاریخ انتشار 2002