6AHO

Crystal structure of Kap114p

6AHO の概要

• エントリーDOI: 10.2210/pdb6aho/pdb
• 分子名称: Importin subunit beta-5 (1 entity in total)
• 機能のキーワード: karyopherin, tata box binding protein, transcription, nuclear transport, protein transport
• 由来する生物種: Saccharomyces cerevisiae (Baker's yeast)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 114431.15

構造登録者

Liao, C.C.,Shankar, S.,Ahmed, G.R.,Hsia, K.C. (登録日: 2018-08-20, 公開日: 2019-10-23, 最終更新日: 2024-03-27)

主引用文献

Liao, C.C.,Shankar, S.,Pi, W.C.,Chang, C.C.,Ahmed, G.R.,Chen, W.Y.,Hsia, K.C.
Karyopherin Kap114p-mediated trans-repression controls ribosomal gene expression under saline stress.
Embo Rep., 21:-, 2020

PubMed Abstract: Nuclear accessibility of transcription factors controls gene expression, co-regulated by Ran-dependent nuclear localization and a competitive regulatory network. Here, we reveal that nuclear import factor-facilitated transcriptional repression attenuates ribosome biogenesis under chronic salt stress. Kap114p, one of the karyopherin-βs (Kap-βs) that mediates nuclear import of yeast TATA-binding protein (yTBP), exhibits a yTBP-binding affinity four orders of magnitude greater than its counterparts and suppresses binding of yTBP with DNA. Our crystal structure of Kap114p reveals an extensively negatively charged concave surface, accounting for high-affinity basic-protein binding. KAP114 knockout in yeast leads to a high-salt growth defect, with transcriptomic analyses revealing that Kap114p modulates expression of genes associated with ribosomal biogenesis by suppressing yTBP binding to target promoters, a trans-repression mechanism we attribute to reduced nuclear Ran levels under salinity stress. Our findings reveal that Ran integrates the nuclear transport pathway and transcription regulatory network, allowing yeast to respond to environmental stresses.

PubMed: 32484313
DOI: 10.15252/embr.201948324

実験手法

X-RAY DIFFRACTION (2.502 Å)