Fig. 8.

Effect of Nedd4-2 WW domain mutant Mut-WW3/WW4 on hOAT1 cell surface expression. (A, top panel) hOAT1-expressing COS-7 cells were transfected with cDNAs for wild-type Nedd4-2 or for Nedd4-2 WW domain mutant (Mut-WW3/WW4). Cell surface biotinylation was then performed. Biotinylated/cell surface proteins were separated with streptavidin beads and analyzed by immunoblotting (IB) with an anti-myc antibody. (Bottom panel) The same immunoblot from the top panel was reprobed by anti-E-cadherin antibody to determine the expression of the cell surface protein marker E-cadherin. (B) Densitometry plot of results from (A, top panel) as well as from other independent experiments. The values are mean ± S.E. (n = 3). *P < 0.05.