title: Ligand-induced Ordering of the C-terminal Tail Primes STING for Phosphorylation by TBK1.
abstract: The innate immune protein Stimulator of interferon genes (STING) promotes the induction of interferon beta (IFN-β) production via the phosphorylation of its C-terminal tail (CTT) by TANK-binding kinase 1 (TBK1). Potent ligands of STING are, therefore, promising candidates for novel anti-cancer drugs or vaccine adjuvants. However, the intrinsically flexible CTT poses serious problems in in silico drug discovery. Here, we performed molecular dynamics simulations of the STING fragment containing the CTT in ligand-bound and unbound forms and observed that the binding of a potent ligand cyclic GMP-AMP (cGAMP) induced a local structure in the CTT, reminiscent of the known structure of a TBK1 substrate. The subsequent molecular biological experiments confirmed the observed dynamics of the CTT and identified essential residues for the activation of the IFN-β promoter, leading us to propose a new mechanism of STING activation.
authors.affiliation: Laboratory of Bioinformatics, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, Osaka 567-0085, Japan. Electronic address: tsuchiya@protein.osaka-u.ac.jp.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Tsuchiya
authors.affiliation: Laboratory of Aduvant Innovation, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, Osaka 567-0085, Japan.
authors.forename: Nao
authors.initials: N
authors.lastname: Jounai
authors.affiliation: Laboratory of Aduvant Innovation, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, Osaka 567-0085, Japan.
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Takeshita
authors.affiliation: Laboratory of Aduvant Innovation, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, Osaka 567-0085, Japan. Electronic address: kenishii@nibiohn.go.jp.
authors.forename: Ken J
authors.initials: KJ
authors.lastname: Ishii
authors.affiliation: Laboratory of Bioinformatics, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, Osaka 567-0085, Japan. Electronic address: kenji@nibiohn.go.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Mizuguchi
mesh_terms: D001665:Binding Sites; D000242:Cyclic AMP / Q000737:chemistry / Q000378:metabolism; D006152:Cyclic GMP / Q000737:chemistry / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D016899:Interferon-beta / Q000235:genetics / Q000378:metabolism; D008024:Ligands; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D056004:Molecular Dynamics Simulation; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D000072417:Protein Domains; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000099197:STING Protein
chemical_list: D000242:Cyclic AMP; D006152:Cyclic GMP; D016899:Interferon-beta; D008024:Ligands; D008565:Membrane Proteins; D017346:Protein Serine-Threonine Kinases; C532857:STING1 protein, human; D000099197:STING Protein; C403191:TBK1 protein, human
keywords: Molecular dynamics simulation; STING C-terminal tail; TBK1; Type I IFNs; cGAMP.