Figure 6

Fbxo41-dependent cilia disassembly mechanisms differ between mitotic cells and neurons. (a) Scheme showing previously described effects of AuroraA kinase and actin on cilia integrity in RPE1 cells. AuroraA kinase is required for ciliary disassembly, and inhibition with PHA prevents ciliary disassembly in mitotic cells¹⁴. In addition, inhibiting actin polymerization with CytoD, increases ciliary length³⁷. (b-d) RPE1 cells were infected with EGFP or EGFP-Fbxo41^WT, and treated with either DMSO, PHA-680632 (0.5 μM) or CytoD (0.5 μM) for 18 h. Fbxo41-mediated decrease in cilia length and percentage of ciliated cells was rescued by inhibition of Aurora A kinase and inhibition of actin polymerization. (d) Ratio of centrosomal over cytoplasmic Fbxo41 intensity quantified in EGFP-Fbxo41^WT expressing RPE1 cells for each experimental condition in (h). No difference in centrosomal enrichment was observed. (e) Neurons were infected with EGFP or EGFP-Fbxo41^WT, and treated with either DMSO, PHA-680632 (0.5 μM) or CytoD (0.5 μM) for 48 h. Fbxo41-mediated decrease in percentage of ciliated neurons was not rescued by inhibition of Aurora A kinase or inhibition of actin polymerization. (f) Cilia length (in cells containing cilia) in EGFP-Fbxo41^WT expressing neurons was rescued by CytoD but not PHA-680632. Note that in neurons CytoD does not increase cilia length. Data from two independent experiments. Kruskal-Wallis Test, ***p < 0.001 ****p < 0.0001. Data are represented as mean ± SEM.