I have two new papers in the Journal of Biological Chemistry:
Z Zhang, Y Sun, YW Cho, CC Chow, SS Simons. PA1 Protein, a New Competitive Decelerator Acting at More than One Step to Impede Glucocorticoid Receptor-mediated Transactivation. J Biol Chem:42-58 (2012). [PDF]
JA Blackford, C Guo, R Zhu, EJ Dourgherty, CC Chow and SS Simons. Identification of Location and Kinetically Defined Mechanism of Cofactors and Reporter Genes in the Cascade of Steroid-regulated Transactivation. J Biol Chem:40982-95 (2012). [PDF]
Both are applications of our theory for steroid-mediated gene induction. The theory is applicable for any biochemical system where the dose response curve strictly follows a Michaelis-Menten curve. A summary of the theory can be found here and here. Slides for talks on the topic can be found here. In Zhang et al, we use the theory to predict a mechanism for a protein called PA1. In Blackford et al, we show that DNA is the effective rate limiting step for gene transcription in steady state, which we dub concentration limiting step, since there are really no rates at steady state.