Research ArticleBIOCHEMISTRY

Biophysical assay for tethered signaling reactions reveals tether-controlled activity for the phosphatase SHP-1

+ See all authors and affiliations

Science Advances  24 Mar 2017:
Vol. 3, no. 3, e1601692
DOI: 10.1126/sciadv.1601692

You are currently viewing the abstract.

View Full Text

Abstract

Tethered enzymatic reactions are ubiquitous in signaling networks but are poorly understood. A previously unreported mathematical analysis is established for tethered signaling reactions in surface plasmon resonance (SPR). Applying the method to the phosphatase SHP-1 interacting with a phosphorylated tether corresponding to an immune receptor cytoplasmic tail provides five biophysical/biochemical constants from a single SPR experiment: two binding rates, two catalytic rates, and a reach parameter. Tether binding increases the activity of SHP-1 by 900-fold through a binding-induced allosteric activation (20-fold) and a more significant increase in local substrate concentration (45-fold). The reach parameter indicates that this local substrate concentration is exquisitely sensitive to receptor clustering. We further show that truncation of the tether leads not only to a lower reach but also to lower binding and catalysis. This work establishes a new framework for studying tethered signaling processes and highlights the tether as a control parameter in clustered receptor signaling.

Keywords
  • tethered signalling
  • clustered receptors
  • allosteric activation
  • surface plasmon resonance
  • enzymatic catalysis
  • tyrosine phosphatase
  • SHP-1
  • mathematical model
  • stochastic simulations
  • Biochemistry

This is an open-access article distributed under the terms of the Creative Commons Attribution license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

View Full Text

Related Content

More Like This