title: Molecular determinants of a regulatory prolyl isomerization in the signal adapter protein c-CrkII.
abstract: The cellular CT10 regulator of kinase protein (c-CrkII) transmits signals from oncogenic tyrosine kinases to cellular targets. Nuclear magnetic resonance studies had suggested that in chicken c-CrkII a native state prolyl cis-trans isomerization is involved in signal propagation. Corresponding evidence for the closely related human c-CrkII was not obtained. Here we analyzed the kinetics of folding and substrate binding of the two homologues and found that cis-trans isomerization of Pro238 determines target binding in chicken but not in human c-CrkII. A reciprocal mutational analysis uncovered residues that determine the isomeric state at Pro238 and transmit it to the binding site for downstream target proteins. The transfer of these key residues to human c-CrkII established a regulatory proline switch in this protein, as well. We suggest that Pro238 isomerization extends the lifetime of the signaling-active state of c-CrkII and thereby functions as a long-term molecular storage device.
authors.affiliation: Laboratorium für Biochemie und Bayreuther Zentrum für Molekulare Biowissenschaften, Universität Bayreuth , 95440 Bayreuth, Germany.
authors.forename: Philipp A M
authors.initials: PA
authors.lastname: Schmidpeter
authors.forename: Franz X
authors.initials: FX
authors.lastname: Schmid
mesh_terms: D000818:Animals; D001665:Binding Sites; D002645:Chickens; D006801:Humans; D007536:Isomerism; D007700:Kinetics; D062105:Molecular Docking Simulation; D011487:Protein Conformation; D017510:Protein Folding; D050737:Proto-Oncogene Proteins c-crk / Q000737:chemistry* / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D050737:Proto-Oncogene Proteins c-crk