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
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Mentions: The dramatic defect in FA disassembly in DKO cells suggests that arrestins regulate FA turnover. Microtubule targeting of FAs promotes disassembly (Kaverina et al., 1999; Small et al., 2002) in a RhoA-independent manner (Ezratty et al., 2005, 2009). Because arrestins bind clathrin (Goodman et al., 1996) and microtubules (Hanson et al., 2007), we hypothesized that microtubule-bound arrestins might recruit clathrin necessary for FA turnover (Ezratty et al., 2009). To test whether the absence of arrestins specifically affects microtubule-dependent FA disassembly, we treated WT and DKO cells with nocodazole to destabilize microtubules, and then monitored FAs as the microtubules regrew (Figure 5A). Consistent with previous reports, upon nocodazole treatment of WT cells, the number of FAs doubled. In agreement with FA lifetimes determined in live-cell imaging (Figure 4), after 30 min of nocodazole washout, the number of FAs in WT cells returned to baseline level, paralleling microtubule regrowth (Figure 5C). In contrast, DKO cells did not respond to either microtubule destabilization or regrowth, suggesting that microtubules have little effect on FAs in cells lacking arrestins (Figure 5B). Thus arrestins likely participate in microtubule-dependent rapid FA disassembly.
Affiliation: Department of Pharmacology, Vanderbilt University, Nashville, TN 37232.