Phosphorylation of Activation Transcription Factor-2 at Serine 121 by Protein Kinase C Controls c-Jun-mediated Activation of Transcription.
Activation transcription factor-2 (ATF-2) is phosphorylated by various protein kinases, such as JNK/p38/ERK, calmodulin kinase IV, protein kinase A, and protein kinase C (PKC), in response to a variety of stimuli. However, the role of the phosphorylation of ATF-2 by PKC in vivo in the transcriptional control of genes that include the activation protein-1 (AP-1)/cyclic AMP-response element remains to be defined. Using antibodies against the phosphorylated serine residue (Ser(P)) at position 121 of ATF-2, we have demonstrated that PKC phosphorylates ATF-2 at Ser-121 and that phosphorylation of Ser-121 (to yield ATF-2pS121) becomes detectable at the late stage of the response of HeLa cells to 12-O-tetradecanoylphorbol-13-acetate (TPA) and is maintained for more than 2 h. By contrast, phosphorylation of ATF-2 at threonine residues 69 and 71 (Thr-69/71, to yield ATF-2pT69/71) and at Ser-340 and Ser-367 (to yield ATF-2pS340 and ATF-2pS367) is detectable as an immediate early response. Unlike levels of ATF-2pT69/71 and ATF-2pS340, the level of ATF-2pS121 increases in the nuclei of HeLa cells in response to TPA. A serine-to-alanine mutation at position 121 of ATF-2 represses the c-Jun-dependent transcription of AP-1/cyclic AMP-response element reporter genes and also the p300-mediated activation of a Gal4-reporter gene in response to TPA. Our results suggest that the phosphorylation of ATF-2 at Ser-121 plays a key role in the c-Jun-mediated activation of transcription that occurs in response to TPA.
Yamasaki
Takahito
T
Gene Engineering Division, RIKEN BioResource Center, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074.
Takahashi
Akinori
A
Pan
Jianzhi
J
Yamaguchi
Naoto
N
Yokoyama
Kazunari K
KK
D020727:ADP-Ribosylation Factors / Q000235:genetics / Q000378:metabolism*; D051698:Activating Transcription Factor 2 / Q000235:genetics / Q000378:metabolism*; D019943:Amino Acid Substitution; D000818:Animals; D002273:Carcinogens / Q000494:pharmacology; D050881:E1A-Associated p300 Protein / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D020125:Mutation, Missense; D010766:Phosphorylation / Q000187:drug effects / Q000235:genetics; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics / Q000378:metabolism*; D020218:Response Elements / Q000502:physiology; D012694:Serine / Q000235:genetics / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology*
C497105:ATF2 protein, human; D051698:Activating Transcription Factor 2; D002273:Carcinogens; D016755:Proto-Oncogene Proteins c-jun; D018808:Transcription Factor AP-1; D012694:Serine; D050881:E1A-Associated p300 Protein; C494360:EP300 protein, human; C494361:Ep300 protein, mouse; D011493:Protein Kinase C; C486436:Arf2 protein, mouse; D020727:ADP-Ribosylation Factors; D013755:Tetradecanoylphorbol Acetate