Figure 1.
The subcellular site of innate immune signal transduction is defined by the localization of inflexible sorting adaptors. (a) Signaling by plasma membrane-bound Toll family members involves their recruitment to a new subdomain of the cell surface, where they can engage a sorting adaptor. For the Toll family members, the sorting adaptors TIRAP and dMyD88 are located in PIP2-rich regions of the cell surface. (b) TRIF-dependent signaling by TLR4 involves its delivery to endosomes, where the sorting adaptor TRAM resides.