PX-RICS-14-3-3ζ/{theta} Complex Couples N-cadherin-β-Catenin with Dynein-Dynactin to Mediate Its Export from the Endoplasmic Reticulum

• Published in: The Journal of biological chemistry 2010, Vol.285 (21), p.16145-16154
• Main Authors: Nakamura, Tsutomu, Hayashi, Tomoatsu, Mimori-Kiyosue, Yuko, Sakaue, Fumika, Matsuura, Ken, Iemura, Shun-ichiro, Natsume, Toru, Akiyama, Tetsu
• Format: Article
• Language: English
• ISSN: 0021-9258; 1083-351X

We have recently shown that β-catenin-facilitated export of cadherins from the endoplasmic reticulum requires PX-RICS, a β-catenin-interacting GTPase-activating protein for Cdc42. Here we show that PX-RICS interacts with isoforms of 14-3-3 and couples the N-cadherin-β-catenin complex to the microtubule-based molecular motor dynein-dynactin. Similar to knockdown of PX-RICS, knockdown of either 14-3-3ζ or -{theta} resulted in the disappearance of N-cadherin and β-catenin from the cell-cell boundaries. Furthermore, we found that PX-RICS and 14-3-3ζ/{theta} are present in a large multiprotein complex that contains dynein-dynactin components as well as N-cadherin and β-catenin. Both RNAi- and dynamitin-mediated inhibition of dynein-dynactin function also led to the absence of N-cadherin and β-catenin at the cell-cell contact sites. Our results suggest that the PX-RICS-14-3-3ζ/{theta} complex links the N-cadherin-β-catenin cargo with the dynein-dynactin motor and thereby mediates its endoplasmic reticulum export.