Identification of two distinct regions of p38 MAPK required for substrate binding and phosphorylation.
The mechanism by which different mitogen activated protein kinases (MAPKs) distinguish between different substrates is poorly understood. For example, p38 and SAPK4 are two closely related p38 MAPKs that both phosphorylate ATF2 and MBP. However, p38 phosphorylates MAPKAPK-2 and -3, whereas SAPK4 does not. In this study, we have used mutagenesis to determine the regions of p38 required for substrate selection. Alanine scanning mutagenesis identified one region of p38 that was required for its ability to phosphorylate MAPKAPK-2 and -3, but that did not significantly affect its binding to these substrates. Chimeras of p38 and SAPK4 identified a second region of p38 that affected the ability of p38 to both bind and phosphorylate MAPKAPK-2 and -3. Hence, we show for the first time that MAPKs contain two distinct regions for recognizing and phosphorylating protein substrates.
Gum
R J
RJ
Department of Molecular Biology, SmithKline Beecham Pharmaceuticals, King of Prussia, PA19406, USA.
Young
P R
PR
D051698:Activating Transcription Factor 2; D000409:Alanine / Q000235:genetics; D000595:Amino Acid Sequence; D001665:Binding Sites; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D048292:Mitogen-Activated Protein Kinase 13; D020928:Mitogen-Activated Protein Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis / Q000235:genetics; D009154:Mutation / Q000235:genetics; D004676:Myelin Basic Protein / Q000378:metabolism; D010766:Phosphorylation; D011233:Precipitin Tests; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D014157:Transcription Factors / Q000378:metabolism; D014162:Transfection; D048051:p38 Mitogen-Activated Protein Kinases; D000099190:MAP-Kinase-Activated Kinase 2
D051698:Activating Transcription Factor 2; D000409:Alanine; D017362:Cyclic AMP Response Element-Binding Protein; D047908:Intracellular Signaling Peptides and Proteins; D048292:Mitogen-Activated Protein Kinase 13; D020928:Mitogen-Activated Protein Kinases; D004676:Myelin Basic Protein; D017346:Protein Serine-Threonine Kinases; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D048051:p38 Mitogen-Activated Protein Kinases; D000099190:MAP-Kinase-Activated Kinase 2; C497105:ATF2 protein, human; C098416:MAP-kinase-activated kinase 3