These authors contributed equally to this work.
A New Role for Nuclear Transport Factor 2 and Ran: Nuclear Import of CapG
Article first published online: 7 FEB 2008
© 2008 The Authors
Volume 9, Issue 5, pages 695–707, May 2008
How to Cite
Van Impe, K., Hubert, T., De Corte, V., Vanloo, B., Boucherie, C., Vandekerckhove, J. and Gettemans, J. (2008), A New Role for Nuclear Transport Factor 2 and Ran: Nuclear Import of CapG. Traffic, 9: 695–707. doi: 10.1111/j.1600-0854.2008.00720.x
- Issue published online: 7 FEB 2008
- Article first published online: 7 FEB 2008
- Received 25 October 2007, revised and accepted for publication 5 February 2008, uncorrected manuscript published online 7 February 2008, published online 12 March 2008
- actin-binding protein;
- nuclear import;
The small GTPase Ran plays a central role in nucleocytoplasmic transport. Nuclear transport of Ran itself depends on nuclear transport factor 2 (NTF2). Here, we report that NTF2 and Ran control nuclear import of the filamentous actin capping protein CapG. In digitonin-permeabilized cells, neither GTPγS nor the GTP hydrolysis-deficient Ran mutant RanQ69L affect transit of CapG to the nucleus in the presence of cytosol. Obstruction of nucleoporins prevents nuclear transport of CapG, and we show that CapG binds to nucleoporin62. In addition, CapG interacts with NTF2, associates with Ran and is furthermore able to bind the NTF2–Ran complex. NTF2–Ran interaction is required for CapG nuclear import. This is corroborated by a NTF2 mutant with reduced affinity for Ran and a Ran mutant that does not bind NTF2, both of which prevent CapG import. Thus, a ubiquitously expressed protein shuttles to the nucleus through direct association with NTF2 and Ran. The role of NTF2 may therefore not be solely confined to sustaining the Ran gradient in cells.