Fig 7.

GFP-PH^BTK-expressing cells have altered PIP₂ levels, and can be loaded with PIP₂. (A) Phosphoinositides were extracted from whole-cell lysates, and PIP₂ levels were measured using dot blots with antibodies specific to PIP₂. Levels were analyzed and assigned a value of arbitrary densitometric units. PIP₂ levels were lower in GFP-PH^BTK-expressing cells than in wild-type cells. (B) PIP₂ loading in GFP-PH^BTK-expressing cells was confirmed using a BODIPY-labeled PIP₂. Both differential interference contrast (DIC) and fluorescence images are shown. Scale bars represent 25 μm.