Publication Date:
2014-07-06
Description:
Activation of the small guanosine triphosphatase H-Ras by the exchange factor Son of Sevenless (SOS) is an important hub for signal transduction. Multiple layers of regulation, through protein and membrane interactions, govern activity of SOS. We characterized the specific activity of individual SOS molecules catalyzing nucleotide exchange in H-Ras. Single-molecule kinetic traces revealed that SOS samples a broad distribution of turnover rates through stochastic fluctuations between distinct, long-lived (more than 100 seconds), functional states. The expected allosteric activation of SOS by Ras-guanosine triphosphate (GTP) was conspicuously absent in the mean rate. However, fluctuations into highly active states were modulated by Ras-GTP. This reveals a mechanism in which functional output may be determined by the dynamical spectrum of rates sampled by a small number of enzymes, rather than the ensemble average.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4255705/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4255705/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Iversen, Lars -- Tu, Hsiung-Lin -- Lin, Wan-Chen -- Christensen, Sune M -- Abel, Steven M -- Iwig, Jeff -- Wu, Hung-Jen -- Gureasko, Jodi -- Rhodes, Christopher -- Petit, Rebecca S -- Hansen, Scott D -- Thill, Peter -- Yu, Cheng-Han -- Stamou, Dimitrios -- Chakraborty, Arup K -- Kuriyan, John -- Groves, Jay T -- P01 AI091580/AI/NIAID NIH HHS/ -- R01 AI104789/AI/NIAID NIH HHS/ -- Howard Hughes Medical Institute/ -- New York, N.Y. -- Science. 2014 Jul 4;345(6192):50-4. doi: 10.1126/science.1250373.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute, Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA. ; Department of Chemical Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA. ; Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA. ; Department of Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720, USA. ; Department of Chemistry, MIT, Cambridge, MA 02139, USA. ; Mechanobiology Institute, National University of Singapore, Singapore. ; Department of Chemistry and Nano-Science Center, University of Copenhagen, Copenhagen, Denmark. ; Department of Chemical Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA. Department of Chemistry, MIT, Cambridge, MA 02139, USA. Department of Biological Engineering, MIT, Cambridge, MA 02139, USA. Ragon Institute of Massachusetts General Hospital, MIT, and Harvard, Cambridge, MA 02139, USA. Department of Physics, MIT, Cambridge, MA 02139, USA. Institute for Medical Engineering and Science, MIT, Cambridge, MA 02139, USA. ; Howard Hughes Medical Institute, Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA. Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA. Physical Biosciences and Materials Sciences Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. ; Howard Hughes Medical Institute, Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA. Mechanobiology Institute, National University of Singapore, Singapore. Physical Biosciences and Materials Sciences Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. Berkeley Education Alliance for Research in Singapore, 1 Create Way, CREATE tower level 11, University Town, Singapore 138602. jtgroves@lbl.gov.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24994643" target="_blank"〉PubMed〈/a〉
Keywords:
Allosteric Regulation
;
Catalytic Domain
;
Crystallography, X-Ray
;
Enzyme Activation
;
Humans
;
Kinetics
;
Nucleotides/chemistry
;
*Protein Interaction Domains and Motifs
;
Proto-Oncogene Proteins p21(ras)/*agonists
;
Son of Sevenless Protein, Drosophila/*chemistry/genetics
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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