Structural mechanism for the arginine sensing and regulation of CASTOR1 in the mTORC1 signaling pathway.
Structural mechanism for the arginine sensing and regulation of CASTOR1 in the mTORC1 signaling pathway.
复制标题
mTORC1 信号通路中 CASTOR1 精氨酸传感和调节的结构机制。
DOI：
10.1038/celldisc.2016.51
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发表时间：
2016
期刊：
影响因子：
33.5
通讯作者：
中科院分区：
文献类型：
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作者：
The mTOR complex I (mTORC1) signaling pathway controls many metabolic processes and is regulated by amino acid signals, especially arginine. CASTOR1 has been identified as the cytosolic arginine sensor for the mTORC1 pathway, but the molecular mechanism of how it senses arginine is elusive. Here, by determining the crystal structure of human CASTOR1 in complex with arginine, we found that an exquisitely tailored pocket, carved between the NTD and the CTD domains of CASTOR1, is employed to recognize arginine. Mutation of critical residues in this pocket abolished or diminished arginine binding. By comparison with structurally similar aspartate kinases, a surface patch of CASTOR1-NTD on the opposite side of the arginine-binding site was identified to mediate direct physical interaction with its downstream effector GATOR2, via GATOR2 subunit Mios. Mutation of this surface patch disrupted CASTOR1’s recognition and inhibition of GATOR2, revealed by in vitro pull-down assay. Normal mode (NM) analysis revealed an ‘open’-to-‘closed’ conformational change for CASTOR1, which is correlated to the switching between the exposing and concealing of its GATOR2-binding residues, and is most likely related to arginine binding. Interestingly, the GATOR2-binding sites on the two protomers of CASTOR1 dimer face the same direction, which prompted us to propose a model for how dimerization of CASTOR1 relieves the inhibition of GATOR1 by GATOR2. Our study thus provides a thorough analysis on how CASTOR1 recognizes arginine, and describes a possible mechanism of how arginine binding induces the inter-domain movement of CASTOR1 to affect its association with GATOR2.
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影响因子：
8.8
作者：
Chantranupong L;Wolfson RL;Orozco JM;Saxton RA;Scaria SM;Bar-Peled L;Spooner E;Isasa M;Gygi SP;Sabatini DM
通讯作者：
Sabatini DM
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
6.8
作者：
Chipman, DM;Shaanan, B
通讯作者：
Shaanan, B
影响因子：
6.8
作者：
Lang, Eric J. M.;Cross, Penelope J.;Parker, Emily J.
通讯作者：
Parker, Emily J.
MTORC1的信号整合与生物合成输出相协调的营养输入。
影响因子：
21.3
作者：
通讯作者：
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