5GXW

Importin and NuMA complex

5GXW の概要

• エントリーDOI: 10.2210/pdb5gxw/pdb
• 分子名称: Importin subunit alpha-1, Peptide from Nuclear mitotic apparatus protein 1 (3 entities in total)
• 機能のキーワード: importin numa complex, protein binding
• 由来する生物種: Mus musculus (Mouse); 詳細
• 細胞内の位置: Cytoplasm : P52293; Nucleus . Isoform 3: Cytoplasm, cytosol . Isoform 4: Cytoplasm, cytosol : Q14980
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 49446.52

構造登録者

Chang, C.-C.,Huang, T.-L.,Hsia, K.-C. (登録日: 2016-09-20, 公開日: 2017-10-04, 最終更新日: 2024-03-20)

主引用文献

Chang, C.-C.,Huang, T.-L.,Shimamoto, Y.,Tsai, S.-Y.,Hsia, K.-C.
Regulation of mitotic spindle assembly factor NuMA by Importin-beta
J. Cell Biol., 216:3453-3462, 2017

PubMed Abstract: Ran-guanosine triphosphatase orchestrates mitotic spindle assembly by modulation of the interaction between Importin-α/-β and spindle assembly factors (SAFs). The inhibition of SAFs performed by importins needs to be done without much sequestration from abundant nuclear localization signal (NLS) -containing proteins. However, the molecular mechanisms that determine NLS-binding selectivity and that inhibit activity of Importin-β-regulated SAFs (e.g., nuclear mitotic apparatus protein [NuMA]) remain undefined. Here, we present a crystal structure of the Importin-α-NuMA C terminus complex showing a novel binding pattern that accounts for selective NLS recognition. We demonstrate that, in the presence of Importin-α, Importin-β inhibits the microtubule-binding function of NuMA. Further, we have identified a high-affinity microtubule-binding region that lies carboxyl-terminal to the NLS, which is sterically masked by Importin-β on being bound by Importin-α. Our study provides mechanistic evidence of how Importin-α/-β regulates the NuMA functioning required for assembly of higher-order microtubule structures, further illuminating how Ran-governed transport factors regulate diverse SAFs and accommodate various cell demands.

PubMed: 28939615
DOI: 10.1083/jcb.201705168

実験手法

X-RAY DIFFRACTION (2.394 Å)