Contribution of the LIM Domain and Nebulin-Repeats to the Interaction of Lasp-2 with Actin Filaments and Focal Adhesions |
| |
| Authors: | Hiroyuki Nakagawa Hiroshi Suzuki Satoshi Machida Junko Suzuki Kazuyo Ohashi Mingyue Jin Shigeaki Miyamoto Asako G Terasaki |
| |
| Institution: | 1. Division of Biology, Faculty of Science, Fukuoka University, Fukuoka, Japan.; 2. Graduate School of Advanced Integration Science, Chiba University, Chiba, Japan.; 3. Department of Biology, Chiba University, Chiba, Japan.; 4. Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Iizuka, Fukuoka, Japan.;University of Birmingham, United Kingdom |
| |
| Abstract: | Lasp-2 binds to actin filaments and concentrates in the actin bundles of filopodia and lamellipodia in neural cells and focal adhesions in fibroblastic cells. Lasp-2 has three structural regions: a LIM domain, a nebulin-repeat region, and an SH3 domain; however, the region(s) responsible for its interactions with actin filaments and focal adhesions are still unclear. In this study, we revealed that the N-terminal fragment from the LIM domain to the first nebulin-repeat module (LIM-n1) retained actin-binding activity and showed a similar subcellular localization to full-length lasp-2 in neural cells. The LIM domain fragment did not interact with actin filaments or localize to actin filament bundles. In contrast, LIM-n1 showed a clear subcellular localization to filopodial actin bundles. Although truncation of the LIM domain caused the loss of F-actin binding activity and the accumulation of filopodial actin bundles, these truncated fragments localized to focal adhesions. These results suggest that lasp-2 interactions with actin filaments are mediated through the cooperation of the LIM domain and the first nebulin-repeat module in vitro and in vivo. Actin filament binding activity may be a major contributor to the subcellular localization of lasp-2 to filopodia but is not crucial for lasp-2 recruitment to focal adhesions. |
| |
| Keywords: | |
|
|
