Carl J Smith, Andrew G Wagner, Robert T Stagnitta, Zihan Xu, John L Pezzullo, José-Luis Giner, Jian Xie, Douglas F Covey, Chunyu Wang, Brian P Callahan
Biochemistry 2020 Feb 18Hedgehog proteins, a family of vital cell signaling factors, are expressed in precursor form, which requires specialized autoprocessing, called cholesterolysis, for full biological activity. Cholesterolysis occurs in cis through the action of the precursor's C-terminal enzymatic domain, HhC. In this work, we describe HhC activator compounds (HACs), a novel class of noncovalent modulators that induce autoprocessing infidelity, diminishing native cholesterolysis in favor of precursor autoproteolysis, an otherwise minor and apparently nonphysiological side reaction. HAC-induced autoproteolysis generates hedgehog protein that is cholesterol free and hence signaling deficient. The most effective HAC has an AC50 of 9 μM, accelerates HhC autoproteolytic activity by 225-fold, and functions in the presence and absence of cholesterol, the native substrate. HACs join a rare class of "antagonists" that suppress native enzymatic activity by subverting mechanistic fidelity.
Carl J Smith, Andrew G Wagner, Robert T Stagnitta, Zihan Xu, John L Pezzullo, José-Luis Giner, Jian Xie, Douglas F Covey, Chunyu Wang, Brian P Callahan. Subverting Hedgehog Protein Autoprocessing by Chemical Induction of Paracatalysis. Biochemistry. 2020 Feb 18;59(6):736-741
PMID: 32013401
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