Fig 3. The highly conserved C-terminus of HID-1 serves as the functional domain.

(A) Secretion assays were performed using HID-1 KO PC12 cells stably expressing WT HID-1 or indicated HID-1 truncations. Cellular and secreted SgII were measured by quantitative fluorescent immunoblotting as described in Fig 2, with the secreted SgII normalized to actin and expressed as percent of basal secretion in the KO (B), and the cellular SgII normalized to actin (C). *, p < 0.05; **, p < 0.01 relative to KO (n = 3) by one-way ANOVA. The bar graphs indicate mean ± s.e. (D) HID-1 KO INS-1 cells were stably transfected with indicated constructs. Cells were fixed, immunostained for HA and TGN38, and imaged using a spinning disk confocal. Scale bars indicate 10μm.