FIGURE 3.
Myo1b IQ-tail binding to liposomes containing PI, PIP2, or PIP3 as a function of lipid concentration. Pulldown assays of liposomes and Myo1b IQ-tail (25 nm) were performed with various concentrations of liposomes composed of 5% PI (◇), PIP2 (○), or PIP3 (●). Data are representative of three experiments for PIP2 and two experiments for PI and PIP3. The concentration at which 50% Myo1b IQ-tail bound PIP2 (KPIP2) was 6 nm, and the concentration at which 50% Myo1b IQ-tail bound PIP3 (KPIP3) was 32 nm. Inset, binding of 50 nm Myo1c IQ-tail to liposomes containing 5% PIP2 at various concentrations. The solid line is the best fit to a hyperbola yielding Klipid = 31.8 μm and KPIP2 = 0.8 μm.