7VV8

Crystal Structure of HRasQ61L(GMPPNP-bound) in complex with the Ras-binding domain(RBD) of SIN1

Summary for 7VV8

• Entry DOI: 10.2210/pdb7vv8/pdb
• Descriptor: GTPase HRas, Target of rapamycin complex 2 subunit MAPKAP1, PHOSPHOAMINOPHOSPHONIC ACID-GUANYLATE ESTER, ... (5 entities in total)
• Functional Keywords: ras, rbd, cell cycle
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 2
• Total formula weight: 29304.91

Authors

Zheng, Y.Y.,Zhou, C. (deposition date: 2021-11-04, release date: 2022-05-18, Last modification date: 2023-11-29)

Primary citation

Zheng, Y.,Ding, L.,Meng, X.,Potter, M.,Kearney, A.L.,Zhang, J.,Sun, J.,James, D.E.,Yang, G.,Zhou, C.
Structural insights into Ras regulation by SIN1.
Proc.Natl.Acad.Sci.USA, 119:e2119990119-e2119990119, 2022

PubMed Abstract: Over the years it has been established that SIN1, a key component of mTORC2, could interact with Ras family small GTPases through its Ras-binding domain (RBD). The physical association of Ras and SIN1/mTORC2 could potentially affect both mTORC2 and Ras-ERK pathways. To decipher the precise molecular mechanism of this interaction, we determined the high-resolution structures of HRas/KRas-SIN1 RBD complexes, showing the detailed interaction interface. Mutation of critical interface residues abolished Ras-SIN1 interaction and in SIN1 knockout cells we demonstrated that Ras-SIN1 association promotes SGK1 activity but inhibits insulin-induced ERK activation. With structural comparison and competition fluorescence resonance energy transfer (FRET) assays we showed that HRas-SIN1 RBD association is much weaker than HRas-Raf1 RBD but is slightly stronger than HRas-PI3K RBD interaction, providing a possible explanation for the different outcome of insulin or EGF stimulation. We also found that SIN1 isoform lacking the PH domain binds stronger to Ras than other longer isoforms and the PH domain appears to have an inhibitory effect on Ras-SIN1 binding. In addition, we uncovered a Ras dimerization interface that could be critical for Ras oligomerization. Our results advance our understanding of Ras-SIN1 association and crosstalk between growth factor-stimulated pathways.

PubMed: 35522713
DOI: 10.1073/pnas.2119990119

Experimental method

X-RAY DIFFRACTION (1.7 Å)