Journal
JOURNAL OF CELLULAR BIOCHEMISTRY
Volume 118, Issue 8, Pages 2285-2294Publisher
WILEY
DOI: 10.1002/jcb.25882
Keywords
CALMODULIN; DEATH RECEPTOR 5; DISC; DR5 OLIGOMERIZATION; APOPTOSIS; BREAST CANCER CELLS
Categories
Funding
- NIH K25 award [5K25CA140791]
Ask authors/readers for more resources
Activation of death receptor-5 (DR5) leads to the formation of death-inducing signaling complex (DISC) for apoptotic signaling. TRA-8, a DR5 specific agonistic antibody, has demonstrated significant cytotoxic activity in vitro and in vivo without inducing hepatotoxicity. Calmodulin (CaM) that is overexpressed in breast cancer plays a critical role in regulating DR5-mediated apoptosis. However, the mechanism of CaM in regulating DR5-mediated apoptotic signaling remains unknown. In this study, we characterized CaM binding to DR5-mediated DISC for apoptosis in TRA-8 sensitive breast cancer cell lines using co-immunoprecipitation, fluorescence microscopic imaging, caspase signaling analysis, and cell viability assay. Results show that upon DR5 activation, CaM was recruited into DR5-mediated DISC in a calcium dependent manner. CaM antagonist, trifluoperazine (TFP), inhibited CaM recruitment into the DISC and attenuated DISC formation. DR5 oligomerization is critical for DISC formation for apoptosis. TFP decreased TRA-8 activated DR5 oligomerization, which was consistent with TFP's effect on DR5-mediated DISC formation. TFP and Ca2+ chelator, EGTA, impeded TRA-8-activated caspase-dependent apoptotic signaling, and TFP decreased TRA-8-induced cell cytotoxicity. These results demonstrated CaM binding to DR5-mediated DISC in a calcium dependent manner and may identify CaM as a key regulator of DR5-mediated DISC formation for apoptosis in breast cancer. J. Cell. Biochem. 118: 2285-2294, 2017. (c) 2017 Wiley Periodicals, Inc.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available