KRAS Ubiquitination at Lysine 104 Retains Exchange Factor Regulation by Dynamically Modulating the Conformation of the Interface

Guowei Yin; Jerry Zhang; Vinay Nair; Vinh Truong; Angelo Chaia; Johnny Petela; Joseph Harrison; Alemayehu A Gorfe; Sharon L Campbell

doi:10.1016/j.isci.2020.101448

KRAS Ubiquitination at Lysine 104 Retains Exchange Factor Regulation by Dynamically Modulating the Conformation of the Interface

iScience. 2020 Aug 10;23(9):101448. doi: 10.1016/j.isci.2020.101448. eCollection 2020 Sep 25.

Authors

Guowei Yin^{1

2}, Jerry Zhang¹, Vinay Nair^{3

4}, Vinh Truong⁵, Angelo Chaia¹, Johnny Petela¹, Joseph Harrison^{1

5}, Alemayehu A Gorfe^{3

4}, Sharon L Campbell^{1

6}

Affiliations

¹ Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
² The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, Guangdong, China.
³ Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA.
⁴ MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
⁵ Department of Chemistry, University of the Pacific, Stockton, CA, USA.
⁶ Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.

Abstract

RAS proteins function as highly regulated molecular switches that control cellular growth. In addition to regulatory proteins, RAS undergoes a number of posttranslational modifications (PTMs) that regulate its activity. Lysine 104, a hot spot for multiple PTMs, is a highly conserved residue that forms key interactions that stabilize the RAS helix-2(H2)/helix-3(H3) interface. Mutation at 104 attenuates interaction with guanine nucleotide exchange factors (GEFs), whereas ubiquitination at lysine 104 retains GEF regulation. To elucidate how ubiquitination modulates RAS function, we generated monoubiquitinated KRAS at 104 using chemical biology approaches and conducted biochemical, NMR, and computational analyses. We find that ubiquitination promotes a new dynamic interaction network and alters RAS conformational dynamics to retain GEF function. These findings reveal a mechanism by which ubiquitination can regulate protein function.

Keywords: Biochemistry; Biocomputational Method; Structural Biology.

Abstract

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