First Author | Gay O | Year | 2011 |
Journal | Proc Natl Acad Sci U S A | Volume | 108 |
Issue | 28 | Pages | 11464-9 |
PubMed ID | 21709252 | Mgi Jnum | J:174390 |
Mgi Id | MGI:5085960 | Doi | 10.1073/pnas.1104211108 |
Citation | Gay O, et al. (2011) RefilinB (FAM101B) targets FilaminA to organize perinuclear actin networks and regulates nuclear shape. Proc Natl Acad Sci U S A 108(28):11464-9 |
abstractText | The intracellular localization and shape of the nucleus plays a central role in cellular and developmental processes. In fibroblasts, nuclear movement and shape are controlled by a specific perinuclear actin network made of contractile actin filament bundles called transmembrane actin-associated nuclear (TAN) lines that form a structure called the actin cap. The identification of regulatory proteins associated with this specific actin cytoskeletal dynamic is a priority for understanding actin-based changes in nuclear shape and position in normal and pathological situations. Here, we first identify a unique family of actin regulators, the refilin proteins (RefilinA and RefilinB), that stabilize specifically perinuclear actin filament bundles. We next identify the actin-binding filamin A (FLNA) protein as the downstream effector of refilins. Refilins act as molecular switches to convert FLNA from an actin branching protein into one that bundles. In NIH 3T3 fibroblasts, the RefilinB/FLNA complex organizes the perinuclear actin filament bundles forming the actin cap. Finally, we demonstrate that in epithelial normal murine mammary gland (NmuMG) cells, the RefilinB/FLNA complex controls formation of a new perinuclear actin network that accompanies nuclear shape changes during the epithelial-mesenchymal transition (EMT). Our studies open perspectives for further functional analyses of this unique actin-based network and shed light on FLNA function during development and in human syndromes associated with FLNA mutations. |