Mechanistic characterization for c-jun-N-Terminal Kinase 1alpha1.
c-jun-N-terminal kinase 1alpha1 (JNK1alpha1) is a serine/threonine kinase of the mitogen-activated protein (MAP) kinase family that phosphorylates protein transcription factors after activation by a variety of environmental stressors. In this study, the kinetic mechanism for JNK1alpha1 phosphorylation of activating transcription factor 2 (ATF2) was determined utilizing steady-state kinetics in the presence and absence of both ATF2 and ATP competitive inhibitors. Data from initial velocity studies were consistent with a sequential mechanism for JNK1alpha1. AMP-PCP exhibited competitive inhibition versus ATP and pure noncompetitive inhibition versus ATF2. JIP-1 peptide (RPKRPTTLNLF) was competitive versus ATF2 and mixed noncompetitive versus ATP. These data suggest that JNK1alpha1 proceeded via a random sequential kinetic mechanism with non-interacting ATF2 and ATP substrate sites.
Department of Molecular Therapeutics and Drug Discovery, The Scripps Research Institute, Scripps Florida, 5353 Parkside Drive, Jupiter, FL 33458, USA.
Brian
B
Ember
Philip
P
LoGrasso
D051698:Activating Transcription Factor 2 / Q000737:chemistry*; D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry*; D000255:Adenosine Triphosphate / Q000737:chemistry*; D003198:Computer Simulation; D004789:Enzyme Activation; D048055:Mitogen-Activated Protein Kinase 8 / Q000737:chemistry*; D008956:Models, Chemical; D010446:Peptide Fragments / Q000737:chemistry*
C497105:ATF2 protein, human; D051698:Activating Transcription Factor 2; D048868:Adaptor Proteins, Signal Transducing; C520352:JNK-interacting protein 1 (153-163); D010446:Peptide Fragments; D000255:Adenosine Triphosphate; D048055:Mitogen-Activated Protein Kinase 8