Molecular Basis for SH3 Domain Regulation of F-Bar-Mediated Membrane Deformation.
Rao, Y., Ma, Q., Vahedi-Faridi, A., Sundborger, A., Pechstein, A., Puchkov, D., Luo, L., Shupliakov, O., Saenger, W., Haucke, V.(2010) Proc Natl Acad Sci U S A 107: 8213
- PubMed: 20404169 
- DOI: https://doi.org/10.1073/pnas.1003478107
- Primary Citation of Related Structures:  
2X3V, 2X3W, 2X3X - PubMed Abstract: 
Members of the Bin/amphiphysin/Rvs (BAR) domain protein superfamily are involved in membrane remodeling in various cellular pathways ranging from endocytic vesicle and T-tubule formation to cell migration and neuromorphogenesis. Membrane curvature induction and stabilization are encoded within the BAR or Fer-CIP4 homology-BAR (F-BAR) domains, alpha-helical coiled coils that dimerize into membrane-binding modules. BAR/F-BAR domain proteins often contain an SH3 domain, which recruits binding partners such as the oligomeric membrane-fissioning GTPase dynamin. How precisely BAR/F-BAR domain-mediated membrane deformation is regulated at the cellular level is unknown. Here we present the crystal structures of full-length syndapin 1 and its F-BAR domain. Our data show that syndapin 1 F-BAR-mediated membrane deformation is subject to autoinhibition by its SH3 domain. Release from the clamped conformation is driven by association of syndapin 1 SH3 with the proline-rich domain of dynamin 1, thereby unlocking its potent membrane-bending activity. We hypothesize that this mechanism might be commonly used to regulate BAR/F-BAR domain-induced membrane deformation and to potentially couple this process to dynamin-mediated fission. Our data thus suggest a structure-based model for SH3-mediated regulation of BAR/F-BAR domain function.
Organizational Affiliation: 
Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany.