ジャーナル: Mol Cell / 年: 2012 タイトル: Molecular basis for specific regulation of neuronal kinesin-3 motors by doublecortin family proteins. 著者: Judy S Liu / Christian R Schubert / Xiaoqin Fu / Franck J Fourniol / Jyoti K Jaiswal / Anne Houdusse / Collin M Stultz / Carolyn A Moores / Christopher A Walsh / 要旨: Doublecortin (Dcx) defines a growing family of microtubule (MT)-associated proteins (MAPs) involved in neuronal migration and process outgrowth. We show that Dcx is essential for the function of ...Doublecortin (Dcx) defines a growing family of microtubule (MT)-associated proteins (MAPs) involved in neuronal migration and process outgrowth. We show that Dcx is essential for the function of Kif1a, a kinesin-3 motor protein that traffics synaptic vesicles. Neurons lacking Dcx and/or its structurally conserved paralogue, doublecortin-like kinase 1 (Dclk1), show impaired Kif1a-mediated transport of Vamp2, a cargo of Kif1a, with decreased run length. Human disease-associated mutations in Dcx's linker sequence (e.g., W146C, K174E) alter Kif1a/Vamp2 transport by disrupting Dcx/Kif1a interactions without affecting Dcx MT binding. Dcx specifically enhances binding of the ADP-bound Kif1a motor domain to MTs. Cryo-electron microscopy and subnanometer-resolution image reconstruction reveal the kinesin-dependent conformational variability of MT-bound Dcx and suggest a model for MAP-motor crosstalk on MTs. Alteration of kinesin run length by MAPs represents a previously undiscovered mode of control of kinesin transport and provides a mechanism for regulation of MT-based transport by local signals.
Particles were aligned using Spider and Frealign (Sindelar and Downing, 2010)
最終 再構成
想定した対称性 - らせんパラメータ - Δz: 9.2 Å 想定した対称性 - らせんパラメータ - ΔΦ: 27.7 ° アルゴリズム: OTHER / 解像度のタイプ: BY AUTHOR / 解像度: 8.3 Å / 解像度の算出法: FSC 0.5 CUT-OFF / ソフトウェア - 名称: SPIDER, FREALIGN 詳細: A sub-selection of approximately 146,000 tubulin dimers (75% of total dataset) went into the final reconstruction
Chain - #0 - Chain ID: A / Chain - #1 - Chain ID: B / Chain - #2 - Chain ID: C / Chain - #3 - Chain ID: D / Chain - #4 - Chain ID: E / Chain - #5 - Chain ID: F / Chain - #6 - Chain ID: G / Chain - #7 - Chain ID: H
ソフトウェア
名称: Chimera
詳細
Protocol: Rigid body
精密化
空間: REAL / プロトコル: RIGID BODY FIT / 当てはまり具合の基準: cross correlation
得られたモデル
PDB-4atu: Human doublecortin N-DC repeat plus linker, and tubulin (2XRP) docked into an 8A cryo-EM map of doublecortin-stabilised microtubules reconstructed in absence of kinesin
Protocol: flexible fitting. The EM map was zoned around the doublecortin density. The N-DC atomic model (1MJD model 11, aa 38-150) was extended at its C-terminus (aa 151-156) using Chimera. Flexible fitting was performed into the zoned around EM map. The core DC domain (aa 53-129) and the docked W146 region (aa 145-146) were treated as a single rigid body.
精密化
空間: REAL / プロトコル: FLEXIBLE FIT / 当てはまり具合の基準: cross correlation
得られたモデル
PDB-4atu: Human doublecortin N-DC repeat plus linker, and tubulin (2XRP) docked into an 8A cryo-EM map of doublecortin-stabilised microtubules reconstructed in absence of kinesin