Thymosin β15 (Tβ15) is a pleiotropic factor which exerts multiple roles in the development of nervous system and brain diseases. In this study, we found that the expressions of Tβ15 mRNA and protein were substantially increased in several brain regions including hippocampal formation and cerebral cortex, following kainic acid (KA)-evoked seizures in rat. Interestingly, a subset of cortex neurons exhibited nuclear Tβ15 immunoreactivity upon KA treatment. Furthermore, translocation of Tβ15 from cytosol to nuclei was observed in cultured neurons or HeLa cells during staurosporine (STS)-induced apoptosis, which was also verified by time-lapse imaging of YFP-tagged Tβ15. It appeared that localization of Tβ15 is restricted to the cytosol in normal condition by its G-actin-interacting domain, because site-directed mutagenesis of this region resulted in the nuclear localization of Tβ15 in the absence of STS treatment. To explore the role of nuclear Tβ15, we enforced Tβ15 to localize in the nuclei by fusion of Tβ15 with nuclear localization signal (NLS-Tβ15). However, overexpression of NLS-Tβ15 did not alter the viability of cells in response to STS treatment. Collectively, these results suggest that nuclear localization of Tβ15 is a controlled process during KA or STS stimulation, although its functional significance is yet to be clarified.
|Number of pages||6|
|Journal||Biochemical and biophysical research communications|
|Publication status||Published - 2008 Jul 11|
Bibliographical noteFunding Information:
This work was supported by grant from Korea Science and Engineering Foundation grants to M10641280003-07N4128-00310 to W.S., and M1050000004905J000004900 to H.K. A part of this work was technically supported by the core facility service of 21C frontier Brain Research Center (M103KV010023-07K2201-02310 to H.K.).
- Kainic acid
- Nuclear translocation
- Staurosporine-induced apoptosis
- Thymosin β15
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology