Selective response of ternary complex factor Sap1a to different mitogen-activated protein kinase subgroups.
Mitogenic and stres signals results in the activation of extracellular signal-regulated kinases (ERKs) and stress-activated protein kinase/c-Jun N-terminal kinases (SAPK/JNKs), respectively, which are two subgroups of the mitogen-activated protein kinases. A nuclear target of mitogen-activated protein (MAP) kinases is the ternary complex factor Elk-1, which underlies its involvement in the regulation of c-fos gene expression by mitogenic and stress signals. A second ternary complex factor, Sap1a, is coexpressed with Elk-1 in several cell types and shares attributes of Elk-1, the significance of which is not clear. Here we show that Sap1a is phosphorylated efficiently by ERKs but not by SAPK/JNKs. Serum response factor-dependent ternary complex formation by Sap1a is stimulated by ERK phosphorylation but not by SAPK/JNKs. Moreover, Sap1a-mediated transcription is activated by mitogenic signals but not by cell stress. These results suggest that Sap1a and Elk-1 have distinct physiological functions.
Strahl
T
T
Spemann Laboratories, Max-Planck-Institut für Immunbiologie, Freiburg, Germany.
Gille
H
H
Shaw
P E
PE
D016475:3T3 Cells; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli; D006367:HeLa Cells; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D046911:Macromolecular Substances; D051379:Mice; D020929:Mitogen-Activated Protein Kinase Kinases; D020928:Mitogen-Activated Protein Kinases; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016324:Sequence Tagged Sites; D013379:Substrate Specificity; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014157:Transcription Factors; D014162:Transfection; D050807:ets-Domain Protein Elk-1; D050808:ets-Domain Protein Elk-4
D004268:DNA-Binding Proteins; C494112:ELK1 protein, human; C494193:ELK4 protein, human; C494113:Elk1 protein, mouse; C494194:Elk4 protein, mouse; D046911:Macromolecular Substances; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D050807:ets-Domain Protein Elk-1; D050808:ets-Domain Protein Elk-4; D015500:Chloramphenicol O-Acetyltransferase; D011494:Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; C482559:MAP2K4 protein, human; C482562:Map2k4 protein, mouse; D020929:Mitogen-Activated Protein Kinase Kinases; D013755:Tetradecanoylphorbol Acetate