2'3'-cGAMP interactome identifies 2'3'-cGAMP/Rab18/FosB signaling in cell migration control independent of innate immunity.

Abstract

c-di-GAMP was first identified in bacteria to promote colonization, while mammalian 2'3'-cGAMP is synthesized by cGAS to activate STING for innate immune stimulation. However, 2'3'-cGAMP function beyond innate immunity remains elusive. Here, we report that 2'3'-cGAMP promotes cell migration independent of innate immunity. 2'3'-cGAMP interactome analysis identifies the small GTPase Rab18 as a 2'3'-cGAMP binding partner and effector in cell migration control. Mechanistically, 2'3'-cGAMP binds Rab18 to facilitate GTP loading and subsequent Rab18 activation, which further promotes FosB transcription in facilitating cell migration. Induced synthesis of endogenous 2'3'-cGAMP by intrabreast tumor bacterium <i>S. aureus</i> infection or low-dose doxorubicin treatment facilitates cell migration depending on the cGAS/cGAMP/Rab18/FosB signaling. We find that lovastatin induces Rab18 deprenylation that abolishes 2'3'-cGAMP recognition therefore suppressing cell migration. Together, our study reveals a previously unidentified 2'3'-cGAMP function in cell migration control via the 2'3'-cGAMP/Rab18/FosB signaling that provides additional insights into clinical applications of 2'3'-cGAMP.