Figures & data
Figure 1. Schematic diagram of the retromer and WASH complexes. The retromer cargo-selective complex (CSC) associates with endosomal membranes to sort cargo proteins (e.g. the cation-independent mannose 6-phosphate receptor—CIMPR) into tubules formed by the sorting nexin (SNX) dimer. The retromer CSC also recruits the WASH complex that mediates F-actin production through VPS35 binding to the extended tail of the FAM21 protein (shown in pink). The FKBP15 protein binds to both VPS35 and FAM21. The RME-8 protein has recently been shown to associate with the WASH complex through binding to FAM21 and regulates the kinetics of SNX dimer association-dissociation with the membrane.
Figure 2. Loss of RME-8 function leads to extensive tubulation of endosomes. The expression of RME-8 was silenced using RNAi. After fixation and labeling with antibodies, cells were imaged using an epifluorescence microscope. The knockdown of RME-8 leads to an accumulation of endosomal tubules that are positive for retromer proteins and cargo such as the CIMPR. Scale bar = 20 μm.
Figure 3. FKBP15 is important for WASH complex localization. Cells were transiently transfected with mcherry-tagged FKBP15. In the highly expressing cells FKBP15 forms bright cytoplasmic aggregates that are also positive for WASH complex proteins and RME-8. The retromer protein VPS26 remains associated with endosomes however. Scale bar = 20 μm.
