Selective autophagy controls the stability of transcription factor IRF3 to balance type I interferon production and immune suppression
Authors: Zhiyao Zhao
Yu Zhang
Ling Ma
Yaoxing Wu
Qingxiang Liu
Jun Cui
Yi-Ping Li
Shuai Yang
Shouheng Jin
Journal: Autophagy (2021)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: Antiviral immunity; deubiquitination; immune suppression; selective autophagy; type I interferon signaling.
Affiliations: State Key Laboratory of Oncology in South China, MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou, GD, China., Institute of Human Virology, Zhongshan School of Medicine, and Key Laboratory of Tropical Diseases Control Ministry of Education, Sun Yat-sen University, Guangzhou, GD, China., Department of Infectious Disease, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, GD, China.

Abstract:  IRF3 (interferon regulatory factor 3) is one of the most critical transcription factors in antiviral innate immune signaling, which is ubiquitously expressed in a variety of cells. Although it has been demonstrated that IRF3 can provoke multiple cellular processes during viral infection, including type I interferon (IFN) production, the mechanisms underlying the precise regulation of IRF3 activity are still not completely understood. Here, we report that selective macroautophagy/autophagy mediated by cargo receptor CALCOCO2/NDP52 promotes the degradation of IRF3 in a virus load-dependent manner. Deubiquitinase PSMD14/POH1 prevents IRF3 from autophagic degradation by cleaving the K27-linked poly-ubiquitin chains at lysine 313 on IRF3 to maintain its basal level and IRF3-mediated type I IFN activation. The autophagic degradation of IRF3 mediated by PSMD14 or CALCOCO2 ensures the precise control of IRF3 activity and fine-tunes the immune response against viral infection. Our study reveals the regulatory role of PSMD14 in balancing IRF3-centered IFN activation with immune suppression and provides insights into the crosstalk between selective autophagy and type I IFN signaling.Abbreviations: ATG5: autophagy related gene 5; Baf A1: bafilomycin A1; BECN1: beclin 1; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; CGAS: cyclic GMP-AMP synthase; DDX58/RIG-I: DExD/H-box helicase 58; DUBs: deubiquitinating enzymes; IFN: interferon; IRF3: interferon regulatory factor 3; MAVS: mitochondrial antiviral signaling protein; MOI: multiplicity of infection; PAMPs: pathogen-associated molecule patterns; PBMC: peripheral blood mononuclear cell; PSMD14/POH1: proteasome 26S subunit, non-ATPase 14; RIPA: RLR-induced IRF3-mediated pathway of apoptosis; SeV: Sendai virus; SQSTM1/p62: sequestosome 1; STING1: stimulator of interferon response cGAMP interactor 1; TBK1: TANK binding kinase 1; Ub: ubiquitin; WT: wild type. 

Retracted: No

PubPeer comments:
 In Figure 5D, discontinuity in a Western blot panel is seen (red dash). Furthermore, two of the immuno blots look surprisingly similar (red squares). ![file] , 
 Thank you for raising this concern. We have reviewed all the relative raw data of this experiment, and confirmed that they are correct. The original image of PSMD14 of 2nd IP with different exposure times in Figure 5D are showed here. And the similar images below are due to their IB from the same membrane. ![file] , 
 Why is the 1 s exposure more exposed than the 2 s exposure? I am surprised that you get any background signal in the first lane as long as the original blot is empty. , 
 #3 Thank you for raising this concern. In these figures, we used ChemiDoc imaging system from Bio-rad company to expose and take the images. The imaging system will acquire images and sum up the signal automatically second by second. In this case, it will exhibit a weaker background and stronger target bands in the long-exposed images, while the short-exposed images will show a stronger background. In order to show our background, we showed the shorter exposed image and adjusted the image with higher contrast. This is why the short-exposed image seems to be stronger. Moreover, some resolution of these images will be reduced when converting to PDF, which makes it difficult to observe the weak background. I hope that this response can solve your confusion. ,