Abstract
Bcl-2 protein plays important roles in the regulation of apoptosis. However, the exact mechanism by which Bcl-2 blocks apoptosis is still unclear. In the present study, we found that overexpression of Bcl-2 in human small cell lung carcinoma Ms-1 cells inhibited not only the release of cytochrome c from mitochondria into cytosol but also de novo ceramide synthesis induced by inostamycin, a phosphatidylinositol turnover inhibitor. To investigate the correlation between the structure of Bcl-2 and its inhibitory function in inostamycin-induced apoptosis, Ms-1 cells that stably overexpress domain-deletional mutants of Bcl-2 were established. Transmembrane domain-deleted Bcl-2 failed to inhibit inostamycin-induced de novo ceramide synthesis, whereas it inhibited inostamycin-induced cytochrome c release, indicating that anchoring of Bcl-2 to membrane was a requirement for its inhibitory effect on inostamycin-induced ceramide synthesis, but not cytochrome c release. Thus, the deletion mutant of tarnsmembrane domain of Bcl-2 can suppress inostamycin-induced apoptosis by inhibiting cytochrome c release, a downstream event of ceramide synthesis in the pathway of inostamycin-induced apoptosis. We also found that the BH3 and BH4 domains of Bcl-2 were necessary for inhibition of inostamycin-induced apoptosis, and deletion of BH1 or BH2 did not affect the inhibitory effect of Bcl-2 to inostamycin-induced apoptotic events.
| Original language | English |
|---|---|
| Pages (from-to) | 57-66 |
| Number of pages | 10 |
| Journal | Experimental Cell Research |
| Volume | 286 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2003 May 15 |
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Keywords
- Apoptosis
- Bcl-2
- Ceramide
- Inostamycin
ASJC Scopus subject areas
- Cell Biology
Cite this
Transmembrane domain of Bcl-2 is required for inhibition of ceramide synthesis, but not cytochrome c release in the pathway of inostamycin-induced apoptosis. / Kawatani, Makoto; Uchi, Madoka; Simizu, Siro; Osada, Hiroyuki; Imoto, Masaya.
In: Experimental Cell Research, Vol. 286, No. 1, 15.05.2003, p. 57-66.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Transmembrane domain of Bcl-2 is required for inhibition of ceramide synthesis, but not cytochrome c release in the pathway of inostamycin-induced apoptosis
AU - Kawatani, Makoto
AU - Uchi, Madoka
AU - Simizu, Siro
AU - Osada, Hiroyuki
AU - Imoto, Masaya
PY - 2003/5/15
Y1 - 2003/5/15
N2 - Bcl-2 protein plays important roles in the regulation of apoptosis. However, the exact mechanism by which Bcl-2 blocks apoptosis is still unclear. In the present study, we found that overexpression of Bcl-2 in human small cell lung carcinoma Ms-1 cells inhibited not only the release of cytochrome c from mitochondria into cytosol but also de novo ceramide synthesis induced by inostamycin, a phosphatidylinositol turnover inhibitor. To investigate the correlation between the structure of Bcl-2 and its inhibitory function in inostamycin-induced apoptosis, Ms-1 cells that stably overexpress domain-deletional mutants of Bcl-2 were established. Transmembrane domain-deleted Bcl-2 failed to inhibit inostamycin-induced de novo ceramide synthesis, whereas it inhibited inostamycin-induced cytochrome c release, indicating that anchoring of Bcl-2 to membrane was a requirement for its inhibitory effect on inostamycin-induced ceramide synthesis, but not cytochrome c release. Thus, the deletion mutant of tarnsmembrane domain of Bcl-2 can suppress inostamycin-induced apoptosis by inhibiting cytochrome c release, a downstream event of ceramide synthesis in the pathway of inostamycin-induced apoptosis. We also found that the BH3 and BH4 domains of Bcl-2 were necessary for inhibition of inostamycin-induced apoptosis, and deletion of BH1 or BH2 did not affect the inhibitory effect of Bcl-2 to inostamycin-induced apoptotic events.
AB - Bcl-2 protein plays important roles in the regulation of apoptosis. However, the exact mechanism by which Bcl-2 blocks apoptosis is still unclear. In the present study, we found that overexpression of Bcl-2 in human small cell lung carcinoma Ms-1 cells inhibited not only the release of cytochrome c from mitochondria into cytosol but also de novo ceramide synthesis induced by inostamycin, a phosphatidylinositol turnover inhibitor. To investigate the correlation between the structure of Bcl-2 and its inhibitory function in inostamycin-induced apoptosis, Ms-1 cells that stably overexpress domain-deletional mutants of Bcl-2 were established. Transmembrane domain-deleted Bcl-2 failed to inhibit inostamycin-induced de novo ceramide synthesis, whereas it inhibited inostamycin-induced cytochrome c release, indicating that anchoring of Bcl-2 to membrane was a requirement for its inhibitory effect on inostamycin-induced ceramide synthesis, but not cytochrome c release. Thus, the deletion mutant of tarnsmembrane domain of Bcl-2 can suppress inostamycin-induced apoptosis by inhibiting cytochrome c release, a downstream event of ceramide synthesis in the pathway of inostamycin-induced apoptosis. We also found that the BH3 and BH4 domains of Bcl-2 were necessary for inhibition of inostamycin-induced apoptosis, and deletion of BH1 or BH2 did not affect the inhibitory effect of Bcl-2 to inostamycin-induced apoptotic events.
KW - Apoptosis
KW - Bcl-2
KW - Ceramide
KW - Inostamycin
UR - http://www.scopus.com/inward/record.url?scp=0037447896&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037447896&partnerID=8YFLogxK
U2 - 10.1016/S0014-4827(03)00098-3
DO - 10.1016/S0014-4827(03)00098-3
M3 - Article
C2 - 12729794
AN - SCOPUS:0037447896
VL - 286
SP - 57
EP - 66
JO - Experimental Cell Research
JF - Experimental Cell Research
SN - 0014-4827
IS - 1
ER -