Deconstruction of the ras switching cycle through saturation mutagenesis

Pradeep Bandaru, Neel H. Shah, Moitrayee Bhattacharyya, John P. Barton, Yasushi Kondo, Joshua C. Cofsky, Christine L. Gee, Arup K. Chakraborty, Tanja Kortemme, Rama Ranganathan, John Kuriyan

Research output: Contribution to journalArticlepeer-review

67 Scopus citations

Abstract

Ras proteins are highly conserved signaling molecules that exhibit regulated, nucleotide-dependent switching between active and inactive states. The high conservation of Ras requires mechanistic explanation, especially given the general mutational tolerance of proteins. Here, we use deep mutational scanning, biochemical analysis and molecular simulations to understand constraints on Ras sequence. Ras exhibits global sensitivity to mutation when regulated by a GTPase activating protein and a nucleotide exchange factor. Removing the regulators shifts the distribution of mutational effects to be largely neutral, and reveals hotspots of activating mutations in residues that restrain Ras dynamics and promote the inactive state. Evolutionary analysis, combined with structural and mutational data, argue that Ras has co-evolved with its regulators in the vertebrate lineage. Overall, our results show that sequence conservation in Ras depends strongly on the biochemical network in which it operates, providing a framework for understanding the origin of global selection pressures on proteins.

Original languageEnglish (US)
Article numbere27810
JournaleLife
Volume6
DOIs
StatePublished - Jul 7 2017

ASJC Scopus subject areas

  • General Neuroscience
  • General Biochemistry, Genetics and Molecular Biology
  • General Immunology and Microbiology

Fingerprint

Dive into the research topics of 'Deconstruction of the ras switching cycle through saturation mutagenesis'. Together they form a unique fingerprint.

Cite this