An N-terminal region of translationally controlled tumor protein is required for its antiapoptotic activity

Authors:
Yang Y, Yang F, Xiong Z, Yan Y, Wang X, Nishino M, Mirkovic D, Nguyen J, Wang H, Yang XF
In:
Source: Oncogene
Publication Date: (2005)
Issue: 24(30): 4778-4788
Research Area:
Cancer Research/Cell Biology
Immunotherapy / Hematology
Cells used in publication:
Jurkat
Species: human
Tissue Origin: blood
Platform:
Nucleofectorâ„¢ I/II/2b
Abstract
Bcl-xL plays a critical role in maintaining cell survival. However, the relationship between the potential interaction of Bcl-xL with other cytosolic proteins and the regulation of cell survival remains incompletely defined. We have identified translationally controlled tumor protein (TCTP), a multifunctional protein, as a novel antiapoptotic Bcl-xL-interacting protein. TCTP interacted in vivo and in vitro with Bcl-xL, and their sites have been mapped to an N-terminal region of TCTP and the Bcl-2 homology domain 3 of Bcl-xL. Consistent with a role in maintaining T-cell survival during activation, TCTP was significantly upregulated in murine T cells activated by T-cell antigen receptor (TCR) ligation and CD28 costimulation, which was correlated with the upregulation of Bcl-xL in activated T cells. Moreover, downregulation of TCTP expression by antisense technology in T cells results in the increase of T-cell apoptosis. Furthermore, the N-terminal region of TCTP was required for its ability to inhibit apoptosis. In conclusion, this study has demonstrated that an N-terminal region of a cytosolic protein, TCTP, is required for its binding to Bcl-xL and for its antiapoptotic activity.Oncogene advance online publication, 2 May 2005; doi:10.1038/sj.onc.1208666