An alpaca single-domain antibody blocks filopodia formation by obstructing L-plastin-mediated F-actin bundling.; ; Catillon, Marie et alin FASEB Journal (2010), 24(1), 105-18 L-plastin, a conserved modular F-actin bundling protein, is ectopically expressed in tumor cells and contributes to cell malignancy and invasion. The underlying molecular mechanisms involved remain ... [more ▼] L-plastin, a conserved modular F-actin bundling protein, is ectopically expressed in tumor cells and contributes to cell malignancy and invasion. The underlying molecular mechanisms involved remain unclear, in part, because specific inhibitors of L-plastin are lacking. We used recombinant alpaca-derived L-plastin single-domain antibodies (nanobodies) as effector of L-plastin function in cells. [less ▲] Detailed reference viewed: 208 (1 UL)![]() Molecular basis for dissimilar nuclear trafficking of the actin-bundling protein isoforms T- and L-plastin.; ; et al in Traffic (Copenhagen, Denmark) (2005), 6(4), 335-45 T- and L-plastin are highly similar actin-bundling proteins implicated in the regulation of cell morphology, lamellipodium protrusion, bacterial invasion and tumor progression. We show that T-plastin ... [more ▼] T- and L-plastin are highly similar actin-bundling proteins implicated in the regulation of cell morphology, lamellipodium protrusion, bacterial invasion and tumor progression. We show that T-plastin localizes predominantly to the cytoplasm, whereas L-plastin distributes between nucleus and cytoplasm in HeLa or Cos cells. T-plastin shows nuclear accumulation upon incubation of cells with the CRM1 antagonist leptomycin B (LMB). We identified a Rev-like nuclear export sequence (NES) in T-plastin that is able to export an otherwise nuclear protein in an LMB-dependent manner. Deletion of the NES promotes nuclear accumulation of T-plastin. Mutation of residues L17, F21 or L26 in the T-plastin NES inhibits nuclear efflux. L-plastin harbors a less conserved NES and lacks the F21 T-plastin residue. Insertion of a Phe residue in the L-plastin NES specifically enhances its export activity. These findings explain why both isoforms exhibit specific distribution patterns in eukaryotic cells. [less ▲] Detailed reference viewed: 192 (0 UL) |
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