LST-6/DENND5 functions as a guanine nucleotide exchange factor (GEF) for RAB-10, facilitating exocytic transport. (A–B′) Confocal images showing colocalization between GFP-LST-6^SC and mCherry-RAB-10 or mCherry-DENN-4. The statistical analysis of colocalization was calculated as Pearson’s correlation coefficient, Error bars represent 95% CIs (n = 18 cells from six animals of each genotype). (C–G) An in vitro GEF assay was used to detect the release of MANT-GDP from RAB-10, RAB-8, and RAB-11.1, which was mediated by GST-LST-6, GST-LST-6 DENN, or GST-DENN-4 DENN. (H–J′) Confocal images showing the subcellular localization of GFP-RAB-8^SC, GFP-RAB-11.1^SC, and hTAC-GFP in different genetic backgrounds. Statistical data is shown as box-and-whisker plots with 10th–90th percentile (n = 24 cells from eight animals of each genotype; dots, outliers; boundaries, quartiles; two-tailed Mann–Whitney test). (K–N) mRNA level of DENND5A, DENND5B, apoB in different genetic backgrounds in Huh7 cells. Error bars represent 95% CIs (one-way ANOVA test with Dunn’s multiple comparison). (O–P′) Confocal images showing the subcellular localization of mNeonGreen-3xFlag-RAB-10^KI or VIT-2-mNeonGreen-3xFlag^KI in different genetic backgrounds. Statistical data is shown as box-and-whisker plots with 10th–90th percentile (n = 24 cells from eight animals of each genotype; dots, outliers; boundaries, quartiles; two-tailed Mann–Whitney test).