Imported:YPM/Kd Ste5 Ste11

Category:Parameters - Yeast Pheromone Response Model Back to main model page

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<modelParameter>Kd_Ste5_Ste11 = 0.106</modelParameter> μM

Source

• FCCS studies

Trust

• medium

Additional Details

• Using FCS to estimate concentrations of Ste11 and Ste5, and FCCS to estimate the concentration of Ste11:Ste5, the apparent affinity of interaction of Ste11 and Ste7 is 89 nM. Maeder et al. 2007 PMID 17952059
  • This Kd represents the overall affinity of interaction via direct interaction and indirect interaction (perhaps via a Ste50-Cdc42-Ste20-Ste4 bridge).
  • Because Ste11 and Ste5 interact tightly (see Choi et al. 1994 PMID 8062390), it is unlikely that the interaction mediated by this protein bridge is stronger than the direct interaction, so the actual Kd is likely on the order of 89 nM.

• Using FCS to estimate concentrations of Ste11 and Ste5, and FCCS to estimate the concentration of Ste11:Ste5, the apparent affinity of interaction of Ste11 and Ste5 is 84 nM in the absence of pheromone, and 161 nM two hours after pheromone treatment. Slaughter et al. 2007 PMID 18077328
  • This Kd represents the overall affinity of interaction via direct interaction and indirect interaction (perhaps via a Ste50-Cdc42-Ste20-Ste4 bridge).
  • Because Ste11 and Ste5 interact tightly (see Choi et al. 1994 PMID 8062390), it is unlikely that the interaction mediated by this protein bridge is stronger than the direct interaction.
  • Assuming that the interactions isn't pheromone regulated (the data from Meader et al. 2007 PMID 17952059 suggests that it isn't), and thus the difference in the measured values is due to experimental error, the average Kd is 123 nM.

See Ste5/MAPK cascade interactions for more details.