HECTD3 mediates TRAF3 polyubiquitination and type I interferon induction during bacterial infection
Fubing Li, Yang Li, Huichun Liang, Tao Xu, Yanjie Kong, Maobo Huang, Ji Xiao, Xi Chen, Houjun Xia, Yingying Wu, Zhongmei Zhou, Xiaomin Guo, Chunmiao Hu, Chuanyu Yang, Xu Cheng, Ceshi Chen, Xiaopeng Qi
Fubing Li, Yang Li, Huichun Liang, Tao Xu, Yanjie Kong, Maobo Huang, Ji Xiao, Xi Chen, Houjun Xia, Yingying Wu, Zhongmei Zhou, Xiaomin Guo, Chunmiao Hu, Chuanyu Yang, Xu Cheng, Ceshi Chen, Xiaopeng Qi
View: Text | PDF
Research Article Immunology Infectious disease

HECTD3 mediates TRAF3 polyubiquitination and type I interferon induction during bacterial infection

Abstract

Lysine-63–linked (K63-linked) polyubiquitination of TRAF3 coordinates the engagement of pattern-recognition receptors with recruited adaptor proteins and downstream activator TBK1 in pathways that induce type I IFN. Whether autoubiquitination or other E3 ligases mediate K63-linked TRAF3 polyubiquitination remains unclear. We demonstrated that mice deficient in the E3 ligase gene Hectd3 remarkably increased host defense against infection by intracellular bacteria Francisella novicida, Mycobacterium, and Listeria by limiting bacterial dissemination. In the absence of HECTD3, type I IFN response was impaired during bacterial infection both in vivo and in vitro. HECTD3 regulated type I IFN production by mediating K63-linked polyubiquitination of TRAF3 at residue K138. The catalytic domain of HECTD3 regulated TRAF3 K63 polyubiquitination, which enabled TRAF3-TBK1 complex formation. Our study offers insights into mechanisms of TRAF3 modulation and provides potential therapeutic targets against infections by intracellular bacteria and inflammatory diseases.

Authors

Fubing Li, Yang Li, Huichun Liang, Tao Xu, Yanjie Kong, Maobo Huang, Ji Xiao, Xi Chen, Houjun Xia, Yingying Wu, Zhongmei Zhou, Xiaomin Guo, Chunmiao Hu, Chuanyu Yang, Xu Cheng, Ceshi Chen, Xiaopeng Qi

×

Figure 7

HECTD3 interacts with the TRAF3-TBK1 complex.

Options: View larger image (or click on image) Download as PowerPoint
HECTD3 interacts with the TRAF3-TBK1 complex. (A) Immunoblot analysis of...
(A) Immunoblot analysis of HECTD3 and TRAF3 that coimmunoprecipitated with FLAG-TRAF3 or HA-HECTD3 from lysates of HEK293T cells transfected with plasmids, as indicated. (B) Co-IP analysis of polyubiquitination of TRAF3 mediated by HECTD3 in HEK293T cells transfected with plasmids as indicated. (C) Co-IP analysis of polyubiquitination of TRAF3 by WT and mutant HECTD3 (C823A) in HEK293T cells transfected with plasmids as indicated. (D) Co-IP analysis of endogenous TRAF3 with TBK1 and HECTD3 in WT and Hectd3–/– BMDMs with or without F. novicida infection for 6 hours. (E) Confocal microscopy analysis of colocalization of TBK1 and TRAF3, and phosphorylation of TBK1 cellular localization in WT and Hectd3–/– BMDMs with or without F. novicida infection for 6 hours. Scale bars: 10 μm. (F) Quantification of colocalization of TBK1 and TRAF3 in E **P < 0.01. (G) Co-IP analysis of polyubiquitination of endogenous TRAF3 in WT and Hectd3–/– BMDMs with or without F. novicida infection for 6 hours. Data represent 3 independent experiments for A–F and 2 independent experiments for G.