When Rab GTPases meet innate immune signaling pathways

Ras-related protein in brain (Rab) GTPases, the subfamily of small GTP-binding proteins superfamily, play a vital role in regulating and controlling vesicles' transport between different membrane-bound organelles. As the first-line defense against invading pathogens, the host's innate immune system recognizes various pathogen-associated molecular patterns through a series of membrane-bound or cytoplasmic pathogen recognition receptors to activate the downstream signaling pathway and induce the type I interferons (IFN-I). Numerous studies have demonstrated that Rab GTPases participate in innate immunity by regulating transmembrane signals' transduction and the transport, adhesion, anchoring, and fusion of vesicles. However, the underlying mechanism of Rab GTPases regulating innate immunity is not entirely understood. A comprehensive understanding of the interplay between the Rab GTPases and innate immunity will help develop novel therapeutics against microbial infections and chronic inflammations.