Fig. 3.

Kv1.5 subunits with intact Src family SH3 domain ligand sequence precipitate from lysates of transfected HEK 293 cells by purified bacterially expressed Src SH3 domains. Shown are Western blots of lysates (top panel) and wild-type Src SH3 domain (wt) and D99N point mutant Src SH3 domain (ko) precipitates (middle andbottom panels) from HEK 293 cells transfected with no channel (control), Kv1.5-wt, or Kv1.5-Δ-Pro. Starting lysate samples contained uniform amounts of Kv1.5 protein (top panel). Identical amounts of Src SH3 fusion protein were added to, and precipitated from, each precipitation reaction (bottom panel). Blots are representative of four experiments.