Download MendeleyAn allosteric switch between the activation loop and a c-terminal palindromic phospho-motif controls c-Src function.
Cuesta-Hernandez, H.N., Contreras, J., Soriano-Maldonado, P., Sanchez-Wandelmer, J., Yeung, W., Martin-Hurtado, A., Munoz, I.G., Kannan, N., Llimargas, M., Munoz, J., Plaza-Menacho, I.(2023) Nat Commun 14: 6548-6548
- PubMed: 37848415
- DOI: https://doi.org/10.1038/s41467-023-41890-7
- Primary Citation of Related Structures:
7OTE - PubMed Abstract:
Autophosphorylation controls the transition between discrete functional and conformational states in protein kinases, yet the structural and molecular determinants underlying this fundamental process remain unclear. Here we show that c-terminal Tyr 530 is a de facto c-Src autophosphorylation site with slow time-resolution kinetics and a strong intermolecular component. On the contrary, activation-loop Tyr 419 undergoes faster kinetics and a cis-to-trans phosphorylation switch that controls c-terminal Tyr 530 autophosphorylation, enzyme specificity, and strikingly, c-Src non-catalytic function as a substrate. In line with this, we visualize by X-ray crystallography a snapshot of Tyr 530 intermolecular autophosphorylation. In an asymmetric arrangement of both catalytic domains, a c-terminal palindromic phospho-motif flanking Tyr 530 on the substrate molecule engages the G-loop of the active kinase adopting a position ready for entry into the catalytic cleft. Perturbation of the phospho-motif accounts for c-Src dysfunction as indicated by viral and colorectal cancer (CRC)-associated c-terminal deleted variants. We show that c-terminal residues 531 to 536 are required for c-Src Tyr 530 autophosphorylation, and such a detrimental effect is caused by the substrate molecule inhibiting allosterically the active kinase. Our work reveals a crosstalk between the activation and c-terminal segments that control the allosteric interplay between substrate- and enzyme-acting kinases during autophosphorylation.
Organizational Affiliation:
Kinases, Protein Phosphorylation and Cancer Group, Structural Biology Programme, Spanish National Cancer Research Center (CNIO), C/Melchor Fernández Almagro num. 3, 28029, Madrid, Spain.
