SUMO-Modified FADD Recruits Cytosolic Drp1 and Caspase-10 to Mitochondria for Regulated Necrosis

ABSTRACT

Fas-associated protein with death domain (FADD) plays a key role in extrinsic apoptosis. Here, we show that FADD is SUMOylated as an essential step during intrinsic necrosis. FADD was modified at multiple lysine residues (K120/125/149) by small ubiquitin-related modifier 2 (SUMO2) during necrosis caused by calcium ionophore A23187 and by ischemic damage. SUMOylated FADD bound to dynamin-related protein 1 (Drp1) in cells both in vitro and in ischemic tissue damage cores, thus promoting Drp1 recruitment by mitochondrial fission factor (Mff) to accomplish mitochondrial fragmentation. Mitochondrial-fragmentation-associated necrosis was blocked by FADD or Drp1 deficiency and SUMO-defective FADD expression. Interestingly, caspase-10, but not caspase-8, formed a ternary protein complex with SUMO-FADD/Drp1 on the mitochondria upon exposure to A23187 and potentiated Drp1 oligomerization for necrosis. Moreover, the caspase-10 L285F and A414V mutants, found in autoimmune lymphoproliferative syndrome and non-Hodgkin lymphoma, respectively, regulated this necrosis. Our study reveals an essential role of SUMOylated FADD in Drp1- and caspase-10-dependent necrosis, providing insights into the mechanism of regulated necrosis by calcium overload and ischemic injury.

KEYWORDS:

• caspase-10
• DRP1
• FADD
• necrosis
• SUMOylation

Supplemental material for this article may be found at https://doi.org/10.1128/MCB.00254-16.

ACKNOWLEDGMENTS

We thank K. Mihara (Kyushu University, Japan) for Drp1 wild-type and knockout MEFs, J. Chang (Thomas Jefferson University) for FADD wild-type and knockout MEFs, and M. T. Ryan (LaTrobe University, Australia) for Fis1, Mff, MiD49, and MiD51.

This work was supported by the Global Research Laboratory (NRF-2010-00341) and a CRI grant (NRF-2016R1A2A1A05005304) funded by the Ministry of Education, Science, and Technology.

Seon-Guk Choi, Hyunjoo Kim, and Ho-June Lee performed mutagenesis, immunoprecipitation assays, and cell line characterization. Seon-Guk Choi and Eun Il Jeong performed myocardial artery occlusion. Seon-Guk Choi and Sungwoo Park performed subcellular fractionation and mitochondrial fragmentation assays. Seon-Guk Choi, Hyunjoo Kim, Song-Yi Lee, and Hyeon-Jeong Lee examined modification of FADD under necrotic stimuli. Seon-Guk Choi, Ho-June Lee, and Seong Won Lee performed in vitro and in vivo SUMOylation assays. Yong-Keun Jung and Chin Ha Chung guided the project and data interpretation. Seon-Guk Choi and Yong-Keun Jung wrote the manuscript.