Structure-based mutagenesis reveals distinct functions for Ras switch 1 and switch 2 in Sos-catalyzed guanine nucleotide exchange

The Journal of Biological Chemistry
B E HallD Bar-Sagi

Abstract

Ras GTPases function as binary switches in signaling pathways controlling cell growth and differentiation. The guanine nucleotide exchange factor Sos mediates the activation of Ras in response to extracellular signals. We have previously solved the crystal structure of nucleotide-free Ras in complex with the catalytic domain of Sos (Boriack-Sjodin, P. A., Margarit, S. M., Bar-Sagi, D., and Kuriyan, J. (1998) Nature 394, 337-343). The structure demonstrates that Sos induces conformational changes in two loop regions of Ras known as switch 1 and switch 2. In this study, we have employed site-directed mutagenesis to investigate the functional significance of the conformational changes for the catalytic function of Sos. Switch 2 of Ras is held in a very tight embrace by Sos, with almost every external side chain coordinated by Sos. Mutagenesis of contact residues at the switch 2-Sos interface shows that only a small set of side chains affect binding, with the most important contact being mediated by tyrosine 64, which is buried in a hydrophobic pocket of Sos in the Ras.Sos complex. Substitutions of Ras and Sos side chains that are inserted into the Mg(2+)- and nucleotide phosphate-binding site of switch 2 (Ras Ala(59) and Sos Leu(9...Continue Reading

References

Jul 1, 1986·Molecular and Cellular Biology·B M WillumsenD R Lowy
Dec 16, 1993·Nature·M S Boguski, F McCormick
Mar 1, 1993·Molecular and Cellular Biology·C C LaiS Powers
Jun 15, 1993·Proceedings of the National Academy of Sciences of the United States of America·M SegalA Levitzki
May 10, 1996·The Journal of Biological Chemistry·L A QuilliamC J Der
Mar 17, 1997·The EMBO Journal·R H ChenD Bar-Sagi
Jul 22, 1997·Biochemistry·J L FelthamR E Oswald
Sep 26, 1997·Nature Structural Biology·Y WeiZ S Derewenda
Feb 3, 1998·Molecular and Cellular Biology·S Corbalan-GarciaD Bar-Sagi
May 23, 1998·The Journal of Biological Chemistry·K IharaT Hakoshima
Aug 5, 1998·Nature·P A Boriack-SjodinJ Kuriyan
Apr 10, 1999·The Journal of Biological Chemistry·N van den BergheA Wittinghofer
May 1, 1994·Trends in Endocrinology and Metabolism : TEM·D Bar-Sagi

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Citations

Dec 4, 2002·Journal of Molecular Biology·Astrid KraemerAlfred Wittinghofer
Feb 6, 2010·Biochemistry·Nicolas NassarMiguel Garcia-Diaz
Nov 8, 2012·Nature Communications·Hao-Hsuan JengDafna Bar-Sagi
Aug 16, 2008·The Journal of Biological Chemistry·Wouter N van EgmondPeter J M van Haastert
Feb 26, 2009·Briefings in Bioinformatics·Nurcan TuncbagRuth Nussinov
Jul 3, 2002·The EMBO Journal·Gretel BuchwaldKlaus Scheffzek
Jun 26, 2007·Journal of Medical Genetics·Martin ZenkerKerstin Kutsche
Jul 23, 2011·Genes & Cancer·Esther Castellano, Eugenio Santos
Nov 1, 2006·Proceedings of the National Academy of Sciences of the United States of America·Tanya S FreedmanJohn Kuriyan
Feb 12, 2014·Proceedings of the National Academy of Sciences of the United States of America·Wan-Chen LinJay T Groves
Sep 6, 2002·Proceedings of the National Academy of Sciences of the United States of America·Brian E HallNicolas Nassar
Jul 19, 2011·Nature Chemical Biology·Anupam PatgiriDafna Bar-Sagi
Dec 2, 2009·The Journal of Cell Biology·Marco GeymonatSteven G Sedgwick
Jan 28, 2016·Chemical Reviews·Shaoyong LuJian Zhang
Dec 3, 2014·Chemistry & Biology·Chris R EvelynYi Zheng
Feb 17, 2005·Journal of Molecular Biology·Jongyun HeoSharon L Campbell
Apr 8, 2015·Proteins·Abhijeet Kapoor, Alex Travesset
Mar 15, 2006·Structure·Bradley FordNicolas Nassar
Nov 7, 2006·Current Biology : CB·Sean BoykevischDafna Bar-Sagi
May 12, 2005·Current Biology : CB·Angus HardingJohn F Hancock
Jan 27, 2009·Biochimica Et Biophysica Acta·Ghazaleh TazminiRobert J Kay
Oct 2, 2014·PloS One·Abhijeet Kapoor, Alex Travesset
Aug 9, 2016·Nature Structural & Molecular Biology·Sune M ChristensenJay T Groves
May 13, 2017·Proteins·Abdallah Sayyed-AhmadAlemayehu A Gorfe
Nov 10, 2006·Critical Reviews in Biochemistry and Molecular Biology·David B Doroquez, Ilaria Rebay
Apr 4, 2018·Cold Spring Harbor Perspectives in Medicine·Pradeep BandaruJohn Kuriyan

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