CD14, TLR4 and TRAM Show Different Trafficking Dynamics During LPS Stimulation
Dionne C.G. Klein, Astrid Skjesol, Esther D. Kers-Rebel, Tatyana Sherstova, Bjørnar Sporsheim, Kjartan W. Egeberg, Bjørn T. Stokke, Terje Espevik and Harald Husebye
Article first published online: 24 MAR 2015 | DOI: 10.1111/tra.12274
We have investigated the location and mobility of toll-like receptor 4 (TLR4) and its adaptor TRAM during lipopolysaccharide (LPS)-induced signaling and how RAB11A regulates TRAM trafficking. We show that LPS induces an immobile fraction of TLR4 in punctate structures containing CD14/LPS and clathrin. RAB11A drives TRAM into the endosomal recycling compartment (ERC) and onto early sorting endosomes. TRAM is recovered more from sorting endosomes than CD14/LPS. Our data suggest that RAB11A regulates LPS-induced interferon-β (IFN-β) production through its ability to transport TRAM form the Golgi to the ERC and further onto sorting endosomes.