PTEN Hopping on the Cell Membrane Is Regulated via a Positively-Charged C2 Domain
Figure 2
Single-molecule imaging of wild-type PTEN and PTENi mutants.
(A) Images of cells expressing wild-type PTEN or PTENi mutants labeled with TMR captured under TIRFM. Scale bar, 5 µm. (B) The numbers of PTEN-Halo-TMR and PTENi-Halo-TMR molecules that remained bound to the membrane are plotted against time after membrane association. Lines are three-component exponential fits (Eq. 1). The cumulative plots were obtained from 16,088 molecules in 8 cells (wild-type PTEN), 12,164 molecules in 8 cells (PTEN1), 9,022 molecules in 7 cells (PTEN2), 11,386 molecules in 8 cells (PTEN3), 12,406 molecules in 8 cells (PTEN4), 11,079 molecules in 8 cells (PTEN5), 10,822 molecules in 7 cells (PTEN6) and 20,683 molecules in 8 cells (PTEN7). (C, D) Dissociation constants k1–3 (C) and frequencies A1–3/k1–3 (D) of PTENi mutants obtained from the fitting in (B). Estimated parameters are shown in Table 2. (E) Frequency of slow, moderate and fast diffusion mobility states, ai, from the displacement distribution analysis in Fig. S3.