The RAB2B-GARIL5 Complex Promotes Cytosolic DNA-Induced Innate Immune Responses
Michihiro Takahama,
Mitsunori Fukuda,
Norihiko Ohbayashi,
Tatsuya Kozaki,
Takuma Misawa,
Toru Okamoto,
Yoshiharu Matsuura,
Shizuo Akira,
Tatsuya Saitoh
Affiliations
Michihiro Takahama
Division of Inflammation Biology, Institute for Enzyme Research, Tokushima University, Tokushima 770-8503, Japan
Mitsunori Fukuda
Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Miyagi 980-8578, Japan
Norihiko Ohbayashi
Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Miyagi 980-8578, Japan
Tatsuya Kozaki
Division of Inflammation Biology, Institute for Enzyme Research, Tokushima University, Tokushima 770-8503, Japan
Takuma Misawa
Laboratory of Host Defense, World Premier International Research Center Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
Toru Okamoto
Department of Molecular Virology, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
Yoshiharu Matsuura
Department of Molecular Virology, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
Shizuo Akira
Laboratory of Host Defense, World Premier International Research Center Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
Tatsuya Saitoh
Division of Inflammation Biology, Institute for Enzyme Research, Tokushima University, Tokushima 770-8503, Japan
Cyclic GMP-AMP synthase (cGAS) is a cytosolic DNA sensor that induces the IFN antiviral response. However, the regulatory mechanisms that mediate cGAS-triggered signaling have not been fully explored. Here, we show the involvement of a small GTPase, RAB2B, and its effector protein, Golgi-associated RAB2B interactor-like 5 (GARIL5), in the cGAS-mediated IFN response. RAB2B-deficiency affects the IFN response induced by cytosolic DNA. Consistent with this, RAB2B deficiency enhances replication of vaccinia virus, a DNA virus. After DNA stimulation, RAB2B colocalizes with stimulator of interferon genes (STING), the downstream signal mediator of cGAS, on the Golgi apparatus. The GTP-binding activity of RAB2B is required for its localization on the Golgi apparatus and for recruitment of GARIL5. GARIL5 deficiency also affects the IFN response induced by cytosolic DNA and enhances replication of vaccinia virus. These findings indicate that the RAB2B-GARIL5 complex promotes IFN responses against DNA viruses by regulating the cGAS-STING signaling axis.
