Design of protein kinase-inducible domains

ORGN 386

Neal J. Zondlo, zondlo@udel.edu, Shalini Balakrishnan, shalinib@udel.edu, Devan Naduthambi, and Christopher W. AmEnde. Department of Chemistry and Biochemistry, University of Delaware, 206 Lammot DuPont Laboratories, Newark, DE 19716
Protein phosphorylation is a ubiquitous signaling mechanism whose target is frequently a nonglobular protein region. We have used protein design to develop novel functional protein architectures, termed protein kinase-inducible domains (pKIDs), whose structures are dependent on phosphorylation by specific protein kinases. We have designed kinase-inducible domains based on a modular architecture, which allows kinase-inducible domains to be responsive to any specific serine-threonine kinase. We have demonstrated that the structure and fluorescence of pKIDs are dependent on phosphorylation, displaying little fluorescence when not phosphorylated and strong fluorescence when phosphorylated. We demonstrate the generality of this architecture with pKID peptides containing recognition sequences for PKA, PKC or Erk. Kinase-inducible domains consist of canonical amino acids, allowing their use as expressible tags of protein kinase activity.