FIG 6.

The carboxy-terminal YV motif in claudin-1 is required for the interaction between claudin-1 and Sec24C. (A) Immunoblots showing the coimmunoprecipitation of Sec24C with full-length wild-type (WT) claudin-1 or claudin-1 mutants in transfected HEK293T cells. Lysates from HEK293T cells expressing Flag–claudin-1 (WT), Flag–claudin-1 (Y/A), Flag–claudin-1 (V/A), Flag–claudin-1 (YV/AA), or PCMV-Tag2 empty vector were incubated with anti-Flag antibody-coated beads, and co-IP proteins were subjected to Western blotting for analysis. (B) Huh7.5.1 cells were subjected to pulldown of the GST-claudin-1 tail or truncation mutants. GST-GKDYV or GST-YV was directly added with KGDYV or YV amino acids at GST C terminus. (C) Huh7.5.1 cell lysates were incubated with different peptides for 30 min, followed by GST–claudin-1 tail pulldown assays. The bound proteins were subjected to Western blotting for analysis. (D) HEK293T cells were transfected with wild-type Sec24C or an Sec24C cargo-deficient mutant (⁸⁹⁵LIL⁸⁹⁷/⁸⁹⁵AAA⁸⁹⁷) and subjected to GST-claudin-1 tail pulldown.