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Title: Phosphotyrosine-mediated LAT assembly on membranes drives kinetic bifurcation in recruitment dynamics of the Ras activator SOS

Abstract

The assembly of cell surface receptors with downstream signaling molecules is a commonly occurring theme in multiple signaling systems. However, little is known about how these assemblies modulate reaction kinetics and the ultimate propagation of signals. Here, we reconstitute phosphotyrosine-mediated assembly of extended linker for the activation of T cells (LAT):growth factor receptor-bound protein 2 (Grb2):Son of Sevenless (SOS) networks, derived from the T-cell receptor signaling system, on supported membranes. Single-molecule dwell time distributions reveal two, well-differentiated kinetic species for both Grb2 and SOS on the LAT assemblies. The majority fraction of membrane-recruited Grb2 and SOS both exhibit fast kinetics and single exponential dwell time distributions, with average dwell times of hundreds of milliseconds. The minor fraction exhibits much slower kinetics, extending the dwell times to tens of seconds. Considering this result in the context of the multistep process by which the Ras GEF (guanine nucleotide exchange factor) activity of SOS is activated indicates that kinetic stabilization from the LAT assembly may be important. This kinetic proofreading effect would additionally serve as a stochastic noise filter by reducing the relative probability of spontaneous SOS activation in the absence of receptor triggering. In conclusion, the generality of receptor-mediated assembly suggests thatmore » such effects may play a role in multiple receptor proximal signaling processes.« less

Authors:
 [1];  [2];  [1];  [1];  [1];  [1];  [1];  [3];  [1]
  1. Univ. of California, Berkeley, CA (United States). Dept. of Chemistry
  2. Univ. of California, Berkeley, CA (United States). Howard Hughes Medical Inst.; Univ. of California, Berkeley, CA (United States). Dept. of Molecular and Cell Biology
  3. Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Univ. of California, Berkeley, CA (United States). Howard Hughes Medical Inst.; Univ. of California, Berkeley, CA (United States). Dept. of Molecular and Cell Biology
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE; National Institutes of Health (NIH)
OSTI Identifier:
1379525
Grant/Contract Number:
AC02-05CH11231; P01 AI091580
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Proceedings of the National Academy of Sciences of the United States of America
Additional Journal Information:
Journal Volume: 113; Journal Issue: 29; Journal ID: ISSN 0027-8424
Publisher:
National Academy of Sciences, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; 59 BASIC BIOLOGICAL SCIENCES; signal transduction; protein assembly; kinetic proofreading; membrane dwell time; single molecule

Citation Formats

Huang, William Y. C., Yan, Qingrong, Lin, Wan-Chen, Chung, Jean K., Hansen, Scott D., Christensen, Sune M., Tu, Hsiung-Lin, Kuriyan, John, and Groves, Jay T. Phosphotyrosine-mediated LAT assembly on membranes drives kinetic bifurcation in recruitment dynamics of the Ras activator SOS. United States: N. p., 2016. Web. doi:10.1073/pnas.1602602113.
Huang, William Y. C., Yan, Qingrong, Lin, Wan-Chen, Chung, Jean K., Hansen, Scott D., Christensen, Sune M., Tu, Hsiung-Lin, Kuriyan, John, & Groves, Jay T. Phosphotyrosine-mediated LAT assembly on membranes drives kinetic bifurcation in recruitment dynamics of the Ras activator SOS. United States. doi:10.1073/pnas.1602602113.
Huang, William Y. C., Yan, Qingrong, Lin, Wan-Chen, Chung, Jean K., Hansen, Scott D., Christensen, Sune M., Tu, Hsiung-Lin, Kuriyan, John, and Groves, Jay T. 2016. "Phosphotyrosine-mediated LAT assembly on membranes drives kinetic bifurcation in recruitment dynamics of the Ras activator SOS". United States. doi:10.1073/pnas.1602602113. https://www.osti.gov/servlets/purl/1379525.
@article{osti_1379525,
title = {Phosphotyrosine-mediated LAT assembly on membranes drives kinetic bifurcation in recruitment dynamics of the Ras activator SOS},
author = {Huang, William Y. C. and Yan, Qingrong and Lin, Wan-Chen and Chung, Jean K. and Hansen, Scott D. and Christensen, Sune M. and Tu, Hsiung-Lin and Kuriyan, John and Groves, Jay T.},
abstractNote = {The assembly of cell surface receptors with downstream signaling molecules is a commonly occurring theme in multiple signaling systems. However, little is known about how these assemblies modulate reaction kinetics and the ultimate propagation of signals. Here, we reconstitute phosphotyrosine-mediated assembly of extended linker for the activation of T cells (LAT):growth factor receptor-bound protein 2 (Grb2):Son of Sevenless (SOS) networks, derived from the T-cell receptor signaling system, on supported membranes. Single-molecule dwell time distributions reveal two, well-differentiated kinetic species for both Grb2 and SOS on the LAT assemblies. The majority fraction of membrane-recruited Grb2 and SOS both exhibit fast kinetics and single exponential dwell time distributions, with average dwell times of hundreds of milliseconds. The minor fraction exhibits much slower kinetics, extending the dwell times to tens of seconds. Considering this result in the context of the multistep process by which the Ras GEF (guanine nucleotide exchange factor) activity of SOS is activated indicates that kinetic stabilization from the LAT assembly may be important. This kinetic proofreading effect would additionally serve as a stochastic noise filter by reducing the relative probability of spontaneous SOS activation in the absence of receptor triggering. In conclusion, the generality of receptor-mediated assembly suggests that such effects may play a role in multiple receptor proximal signaling processes.},
doi = {10.1073/pnas.1602602113},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
number = 29,
volume = 113,
place = {United States},
year = 2016,
month = 7
}

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