Tyrosyl phosphorylation of KRAS stalls GTPase cycle via alteration of switch I and II conformation

• Published in: Nature communications Vol. 10; no. 1; p. 224
• Main Authors: Kano, Yoshihito, Gebregiworgis, Teklab, Marshall, Christopher B., Radulovich, Nikolina, Poon, Betty P. K., St-Germain, Jonathan, Cook, Jonathan D., Valencia-Sama, Ivette, Grant, Benjamin M. M., Herrera, Silvia Gabriela, Miao, Jinmin, Raught, Brian, Irwin, Meredith S., Lee, Jeffrey E., Yeh, Jen Jen, Zhang, Zhong-Yin, Tsao, Ming-Sound, Ikura, Mitsuhiko, Ohh, Michael
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 15.01.2019; Nature Publishing Group; Nature Portfolio
• Subjects: 101/58; 101/6; 42/41; 631/535/878; 631/67; 631/80; 631/80/458/1733; 64; 64/60; 692/4028/67/1504/1713; 82/80; 96/109; 96/95; Alzheimer's disease; Animals; Antineoplastic Agents - pharmacology; Antineoplastic Agents - therapeutic use; Cancer; Carcinoma, Pancreatic Ductal - drug therapy; Clinical trials; GTP Phosphohydrolases - metabolism; HEK293 Cells; Humanities and Social Sciences; Humans; K-Ras protein; Kinases; Male; Medical research; Membrane proteins; Membranes; Mice, SCID; Molecular dynamics; multidisciplinary; Neurodegenerative diseases; Pancreatic Neoplasms - drug therapy; Protein kinase C; Protein Tyrosine Phosphatase, Non-Receptor Type 11 - antagonists & inhibitors; Protein Tyrosine Phosphatase, Non-Receptor Type 11 - metabolism; Proto-Oncogene Proteins p21(ras) - metabolism; raf Kinases - metabolism; Science; Science (multidisciplinary); Xenograft Model Antitumor Assays
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-08115-8

Deregulation of the RAS GTPase cycle due to mutations in the three RAS genes is commonly associated with cancer development. Protein tyrosine phosphatase SHP2 promotes RAF-to-MAPK signaling pathway and is an essential factor in RAS-driven oncogenesis. Despite the emergence of SHP2 inhibitors for the treatment of cancers harbouring mutant KRAS, the mechanism underlying SHP2 activation of KRAS signaling remains unclear. Here we report tyrosyl-phosphorylation of endogenous RAS and demonstrate that KRAS phosphorylation via Src on Tyr32 and Tyr64 alters the conformation of switch I and II regions, which stalls multiple steps of the GTPase cycle and impairs binding to effectors. In contrast, SHP2 dephosphorylates KRAS, a process that is required to maintain dynamic canonical KRAS GTPase cycle. Notably, Src- and SHP2-mediated regulation of KRAS activity extends to oncogenic KRAS and the inhibition of SHP2 disrupts the phosphorylation cycle, shifting the equilibrium of the GTPase cycle towards the stalled ‘dark state’. Deregulation of the RAS GTPase cycle due to mutations in RAS genes is commonly associated with cancer development. Here authors use NMR and mass spectrometry to shows that KRAS phosphorylation via Src alters the conformation of switch I and II regions and thereby impacts the GTPase cycle.