SNX3 localizes to borreliae internalized by macrophages. (A) Domain structure of SNXs. PDZ: PSD95, Dlg1, ZO-1 domain; SH3: Src homology 3 domain. The number of amino acid residues is indicated on the x axis. (B) Quantification of enrichment of SNX fusion constructs at internalized borreliae. The number of internalized borreliae was set to 100%. For specific values, see Table S1. n = 3 (3 × 20 borreliae). (C–H) Confocal micrographs of macrophages expressing GFP-SNX3 (C–E) or stained for endogenous SNX3 (F–H), with internalized borreliae stained by specific antibody (D and G), and merges (E and H). Box indicates area of magnified insets. Scale bars: 10 µm, and 1 µm for insets. See also Video 1. (I) RFP-SNX3 stays associated with compacting borreliae-containing phagosomes. Still images are from confocal time lapse of macrophage with an internalized GFP-expressing B. burgdorferi cell (I1) and RFP-SNX3 (shown in white; I2), with merge (I3; see Video 2). Scale bars: 10 µm for overview images and 2 µm for insets. Error bars: mean ± SEM.