Arrestins regulate cell spreading and motility via focal adhesion dynamics.
Bottom Line: Clathrin exhibited decreased dynamics near FA in arrestin-deficient cells.In contrast to wild-type arrestins, mutants deficient in clathrin binding did not rescue the phenotype.Collectively the data indicate that arrestins are key regulators of FA disassembly linking microtubules and clathrin.
Affiliation: Department of Pharmacology, Vanderbilt University, Nashville, TN 37232.Show MeSH
Related in: MedlinePlus
Mentions: The accumulation and enlargement of FAs in DKO cells (Figure 3, C and D) suggest that the rate of FA disassembly might be reduced. To test this idea, we expressed GFP-paxillin in DKO and WT cells (Figure 4) and measured FA lifetimes using live-cell imaging (Figure 4, A and B). Individual FAs at the leading edge of the cell were tracked from formation to disassembly (representative FAs are indicated by red arrows in Figure 4A). All FAs in WT cells formed and disassembled within 20–40 min (Figure 4B), with a median lifetime of 23 min (Figure 4C). In contrast, lifetimes of FAs in DKO cells showed much broader distribution, with median ∼59 min. Of note, some FAs in DKO cells persisted >3 h (Figure 4B). DKO cells also demonstrated a defect in leading edge formation and loss of polarity (Supplemental Movies S1–S4). To test whether the defect in FA disassembly is a result of the lack of arrestins, we transfected red mCherry-paxillin into cells coexpressing GFP with arrestins (Figure 4D). Live-cell imaging revealed a shift in FA lifetimes toward WT (Figure 4, B and C), with median values reduced to 42 and 40.5 min in cells expressing arrestin-2 and arrestin-3, respectively (Figure 4C). Thus arrestins regulate FA turnover, and normal dynamics requires the presence of both subtypes.
Affiliation: Department of Pharmacology, Vanderbilt University, Nashville, TN 37232.