SLC26A6 C-terminal region interacts with CAII. (A) Amino-acid sequence alignment of human bicarbonate transport proteins, SLC26A6 (GenBank AF279265), and SLC26A3 (GenBank L02785). Shading indicates sequence identity (black) and sequence similarity (gray). Potential CAII-binding sites, consisting of a hydrophobic residue followed by four residues, two of which are acidic, are indicated (black overline). Asterisks mark consensus PKC phosphorylation sites (Expert Protein Analysis System, http://ca.expasy.org/). (B–C) In all, 10 μg of either GST alone (1) or GSTA6-Q497D633 (2) were resolved by SDS–PAGE on 10% acrylamide gels and transferred to PVDF membranes. Blots were incubated with a lysate of HEK293 cells, which endogenously express CAII. Blots were then probed with anti-CAII antibody (B) or anti-GST antibody (C). Arrowheads indicate the migration positions of GST alone (open) and GSTA6-Q496-D633 (filled).