A bacterial RING ubiquitin ligase triggering stepwise degradation of BRISC via TOLLIP-mediated selective autophagy manipulates host inflammatory response. (PubMed, Autophagy)
Further investigations elucidated that ABRAXAS2 degradation triggered the subsequent degradation of adjacent BRCC3, which in turn, hindered TNIP1/ABIN1 degradation, ultimately inhibiting NFKB/NF-κB (nuclear factor kappa B)-mediated inflammatory responses. This chain of events offers valuable insights into the NFKB activation by the K63-specific deubiquitinating role of BRISC, unveiling how bacteria manipulate ubiquitin regulation and selective autophagy within the BRISC network to inhibit the host's inflammatory response and thus dominate a pathogen-host tug-of-war.Abbreviations: 3-MA: 3-methyladenine; A/E: attaching and effacing; ATG7: autophagy related 7; BafA1: bafilomycin A1; BNIP3L/Nix: BCL2 interacting protein 3 like; BRISC: BRCC3 isopeptidase complex; Cas9: CRISPR-associated system 9; co-IP: co-immunoprecipitation; CQ: chloroquine; CRISPR: clustered regulatory interspaced short palindromic repeat; DAPI: 4',6-diamidino2-phenylindole; DMSO: dimethyl sulfoxide; DUB: deubiquitinating enzyme; E. coli: Escherichia coli; EHEC: enterohemorrhagic Escherichia coli; EPEC: enteropathogenic Escherichia coli; GFP: green fluorescent protein; LEE: locus of enterocyte effacement; MAP1LC3B/LC3: microtubule associated protein 1 light chain 3 beta; MG132: cbz-leu-leu-leucinal; MOI: multiplicity of infection; NBR1: NBR1 autophagy cargo receptor; NC: negative control; NFKB/NF-κB: nuclear factor kappa B; NH4Cl: ammonium chloride; OPTN: optineurin; SQSTM1/p62: sequestosome 1; sgRNAs: small guide RNAs; T3SS: type III secretion system; TNF: tumor necrosis factor; TOLLIP: toll interacting protein; TRAF: TNF receptor associated factor; TUBB: tubulin beta class I; WCL: whole cell lysate; WT: wide type.