Experimental validation of computerised models of clustering of platelet glycoprotein receptors that signal via tandem SH2 domain proteins
Fig 7
An agent-based model showing that the effect of a divalent ligand on receptor dimerisation and higher order clustering.
Agent-based modelling was used to study the combination of a divalent ligand, receptor dimerisation and a cytosolic crosslinker on receptor clustering. Unless stated, the parameter values and key are as described in Fig 4. (A) The effect of a divalent ligand on clustering of a receptor that is unable to dimerise in the presence of a moderate affinity crosslinker (i) representative runs at steady-state, the number of divalent ligands is varied from 25–200 as shown in the upper right-hand corner (ii) number of receptors that are phosphorylated at steady-state (iii) number of receptor dimers (R = 2), trimers (R = 3), tetramers (R = 4) and higher order (R>4) structures at steady-state. Results are shown as mean + s.d. of 30 simulations at 3,000 ticks. (B) The effect of a divalent ligand on clustering of receptors with a low basal level of dimerisation (10%) (i) the number of divalent ligands is in the upper right-hand corner, for further details see (A). (C) (i-iii) The effect of a divalent ligand and moderate affinity crosslinking on clustering of receptors with a low basal level of dimerisation (10%) (i) the number of divalent ligands in the upper right-hand corner (iv) representative runs showing the time course of receptor clustering with the tick intervals are shown in the upper right-hand corner; the number of divalent ligands is 200, for further details see (A).