Ca2+/calmodulin kinase types II and IV regulate c-fos transcription in the AtT20 corticotroph cell line.
In the corticotroph cell line AtT20, Ca2+ stimulates c-fos mRNA and nuclear c-fos protein accumulation. We show that Ca2+ stimulates transcription of a chloramphenicol-acetyl-transferase reporter gene driven by the c-fos promoter. This effect is mimicked by both constitutively active Ca2+/calmodulin-dependent protein kinase types II (CamK II) and IV (CamK IV). The effects of CamK IV are synergistic with those obtained by cAMP stimulation, whereas CamK II-dependent transcription is not further stimulated. Deletion of the distal promoter sequence revealed that CamK IV, and to a lesser extent CamK II, activate a cis-acting element(s) located between -99 and -53 bp prior to the transcription initiation site. Moreover, CamK II further stimulates transcription through the fos AP1-like element. CamK IV has a lower effect on this element but represses the serum response element. The latter observation might account for the lower transcriptional effects of CamK IV on the full length c-fos promoter.
Antoine
M
M
Institut de Physiologie et de Chimie Biologie, URA 1446 CNRS, Laboratoire de Physiologie Générale, Université Louis Pasteur, Strasbourg, France.
Gaiddon
C
C
Loeffler
J P
JP
D000818:Animals; D002118:Calcium / Q000378:metabolism; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D005786:Gene Expression Regulation; D051379:Mice; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D016760:Proto-Oncogene Proteins c-fos; D000242:Cyclic AMP; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C517685:Camk4 protein, mouse; D002118:Calcium