Nestin Forms a Flexible Cytoskeleton by Means of a Huge Tail Domain That Is Reversibly Stretched and Contracted by Weak Forces
Ayana Yamagishi,
Rina Tokuoka,
Kazuki Imai,
Mei Mizusawa,
Moe Susaki,
Koki Uchida,
Saku T. Kijima,
Akira Nagasaki,
Daijiro Takeshita,
Chiaki Yoshikawa,
Taro Q. P. Uyeda,
Chikashi Nakamura
Affiliations
Ayana Yamagishi
Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 5 1-1-1 Higashi, Tsukuba 305-8565, Ibaraki, Japan
Rina Tokuoka
Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 5 1-1-1 Higashi, Tsukuba 305-8565, Ibaraki, Japan
Kazuki Imai
Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 5 1-1-1 Higashi, Tsukuba 305-8565, Ibaraki, Japan
Mei Mizusawa
Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 5 1-1-1 Higashi, Tsukuba 305-8565, Ibaraki, Japan
Moe Susaki
Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 5 1-1-1 Higashi, Tsukuba 305-8565, Ibaraki, Japan
Koki Uchida
Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 5 1-1-1 Higashi, Tsukuba 305-8565, Ibaraki, Japan
Saku T. Kijima
Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6 1-1-1 Higashi, Tsukuba 305-8566, Ibaraki, Japan
Akira Nagasaki
Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6 1-1-1 Higashi, Tsukuba 305-8566, Ibaraki, Japan
Daijiro Takeshita
Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6 1-1-1 Higashi, Tsukuba 305-8566, Ibaraki, Japan
Chiaki Yoshikawa
Research Center for Macromolecules and Biomaterials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Ibaraki, Japan
Taro Q. P. Uyeda
Department of Physics, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
Chikashi Nakamura
Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 5 1-1-1 Higashi, Tsukuba 305-8565, Ibaraki, Japan
Nestin is a type VI intermediate filament protein and a well-known neural stem cell marker. It is also expressed in high-grade cancer cells, forming copolymerized filaments with vimentin. We previously showed that nestin inhibits the binding of vimentin’s tail domain to actin filaments (AFs) by steric hindrance through its large nestin tail domain (NTD), thereby increasing three-dimensional cytoskeleton network mobility, enhancing cell flexibility, and promoting cancer progression. Further, we found that nestin itself stably binds to AFs via the NTD. We therefore hypothesized that the NTD may form a flexible cytoskeletal structure by extending with weak force. In vitro tensile tests using atomic force microscopy were performed to assess the mechanical properties of NTDs. The C-terminus of the NTD bound AFs by bringing the AFM tip modified with the NTD into contact with the AFs on the substrate. NTDs were elongated to approximately 80% of their maximum length at weak forces < 150 pN. Repeated tensile tests revealed that the NTD refolded quickly and behaved like a soft elastic material. We speculate that nestin stably binds AFs, and the NTD extends with weak force, contracting quickly upon load release. Thereby, nestin would absorb mechanical load and maintain cytoskeletal integrity.
