| First Author | Mack NA | Year | 2012 |
| Journal | Nat Cell Biol | Volume | 14 |
| Issue | 11 | Pages | 1169-80 |
| PubMed ID | 23103911 | Mgi Jnum | J:194001 |
| Mgi Id | MGI:5470026 | Doi | 10.1038/ncb2608 |
| Citation | Mack NA, et al. (2012) beta2-syntrophin and Par-3 promote an apicobasal Rac activity gradient at cell-cell junctions by differentially regulating Tiam1 activity. Nat Cell Biol 14(11):1169-80 |
| abstractText | Although Rac and its activator Tiam1 are known to stimulate cell-cell adhesion, the mechanisms regulating their activity in cell-cell junction formation are poorly understood. Here, we identify beta2-syntrophin as a Tiam1 interactor required for optimal cell-cell adhesion. We show that during tight-junction (TJ) assembly beta2-syntrophin promotes Tiam1-Rac activity, in contrast to the function of the apical determinant Par-3 whose inhibition of Tiam1-Rac activity is necessary for TJ assembly. We further demonstrate that beta2-syntrophin localizes more basally than Par-3 at cell-cell junctions, thus generating an apicobasal Rac activity gradient at developing cell-cell junctions. Targeting active Rac to TJs shows that this gradient is required for optimal TJ assembly and apical lumen formation. Consistently, beta2-syntrophin depletion perturbs Tiam1 and Rac localization at cell-cell junctions and causes defects in apical lumen formation. We conclude that beta2-syntrophin and Par-3 fine-tune Rac activity along cell-cell junctions controlling TJ assembly and the establishment of apicobasal polarity. |
