RBX1-mediated ubiquitination of SESN2 promotes cell death upon prolonged mitochondrial damage in SH-SY5Y neuroblastoma cells
- 442 Downloads
Sestrins are evolutionary conserved stress-inducible genes which regulate the axis of cell survival and cell death. Suppression of Sestrin 2 (SESN2) has been linked with increase in oxidative stress and cell death but mechanistic details related to regulation of SESN2 during mitochondrial damage remain unknown. Our study shows that prolonged CCCP-induced mitochondrial damage decreases SESN2 levels and viability of SH-SY5Y cells while overexpression of SESN2 significantly rescues the viability of cells. Further, we demonstrate that Ring box protein 1 (RBX1) is a novel interactive partner and E3 ligase for SESN2 which mediates its K-48-linked ubiquitination upon extensive mitochondrial damage. Downregulation of RBX1 causes stabilization in levels of SESN2. Notably, silencing of RBX1 expression substantially declines cell death and generation of mitochondrial ROS in response to prolonged mitochondrial damage. Taken together, we suggest that SESN2 is critical to protect cells against detrimental effect of mitochondrial damage and RBX1 is a negative regulator of SESN2 which hampers its stabilization.
KeywordsSESN2 RBX1 Cell death Ubiquitination
Carbonyl cyanide m-chlorophenylhydrazone
Ring box protein 1
We acknowledge technical assistance from Mr. G.S. Neelaram. This work was supported by grants from the Department of Biotechnology, New Delhi, India (http://dbtindia.nic.in/index.asp), to the National Institute of Immunology (Grant No. BT/03/033/88); Centre for Molecular Medicine, New Delhi (Grant No. BT/PR/14549/MED/14/1291).
AK and CS formed the general framework of this study. AK and CS designed experiments. AK performed all experiments. AK and CS prepared the manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 3.Murphy E, Steenbergen C (2007) Preconditioning: the mitochondrial connection. Annu Rev Physiol 69:51–67. https://doi.org/10.1146/annurev.physiol.69.031905.163645 CrossRefPubMedGoogle Scholar
- 7.Tait SW, Green DR (2013) Mitochondrial regulation of cell death. Cold Spring Harbor Perspect Biol. https://doi.org/10.1101/cshperspect.a008706
- 16.Lee JH, Budanov AV, Park EJ, Birse R, Kim TE, Perkins GA, Ocorr K, Ellisman MH, Bodmer R, Bier E, Karin M (2010) Sestrin as a feedback inhibitor of TOR that prevents age-related pathologies. Science 327(5970):1223–1228. https://doi.org/10.1126/science.1182228 CrossRefPubMedPubMedCentralGoogle Scholar
- 18.Byun JK, Choi YK, Kim JH, Jeong JY, Jeon HJ, Kim MK, Hwang I, Lee SY, Lee YM, Lee IK, Park KG (2017) A positive feedback loop between Sestrin2 and mTORC2 is required for the survival of glutamine-depleted lung cancer cells. Cell Rep 20(3):586–599. https://doi.org/10.1016/j.celrep.2017.06.066 CrossRefPubMedGoogle Scholar
- 23.Yang D, Li L, Liu H, Wu L, Luo Z, Li H, Zheng S, Gao H, Chu Y, Sun Y, Liu J, Jia L (2013) Induction of autophagy and senescence by knockdown of ROC1 E3 ubiquitin ligase to suppress the growth of liver cancer cells. Cell Death Differ 20(2):235–247. https://doi.org/10.1038/cdd.2012.113 CrossRefPubMedGoogle Scholar
- 30.Shortt J, Johnstone RW (2012) Oncogenes in cell survival and cell death. Cold Spring Harbor Perspect Biol. https://doi.org/10.1101/cshperspect.a009829
- 36.Ding B, Parmigiani A, Divakaruni AS, Archer K, Murphy AN, Budanov AV (2016) Sestrin2 is induced by glucose starvation via the unfolded protein response and protects cells from non-canonical necroptotic cell death. Sci Rep 6:22538. https://doi.org/10.1038/srep22538 CrossRefPubMedPubMedCentralGoogle Scholar