Identification of beta-actin sequences necessary for induction by phorbol esters and calcium ionophores.
Transcription of the cytoskeletal beta-actin gene is rapidly induced by phorbol 12-myristate 13-acetate (PMA) and the calcium ionophore, A23187, in cultured H4IIE hepatoma (H4) cells. PMA directly activates protein kinase C (PKC) and activation of PKC is necessary for the cellular actions of PMA, including induction of beta-actin gene transcription. In the present study, we determined the DNA sequence requirements for induction of the beta-actin gene by PMA and A23187. Constructs containing progressive deletions of normal and mutated human beta-actin 5' sequences fused to the reporter gene, bacterial chloramphenicol acetyltransferase, were analysed in transient transfections of H4 cells. We delineated the PMA response DNA element of the human beta-actin gene to the proximal CCArGG box (-62 to -53) in the 5' flanking region. In contrast, A23187 did not induce expression of transfected gene constructs containing this CCArGG box. Additionally, we demonstrated that CCArGG boxes from two other PMA-induced genes in H4 cells, c-fos and gamma-actin, could confer PMA inducibility to a heterologous promoter. This CCArGG box specifically interacts with one or more proteins present in nuclear extracts of H4 cells. These results indicate that in cultured cells, PMA-dependent induction of the beta-actin gene is mediated through the proximal CCArGG box. This suggests that the CCArGG box is a target for PKC action and may be involved in the control of other PKC regulated genes.
Onyia
J E
JE
Department of Physiology, SUNY Health Science Center, Syracuse.
Halladay
D L
DL
Messina
J L
JL
D000199:Actins / Q000235:genetics*; D001483:Base Sequence; D000001:Calcimycin / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D016762:Genes, fos; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D011493:Protein Kinase C / Q000502:physiology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects; D014407:Tumor Cells, Cultured
D000199:Actins; D009687:Nuclear Proteins; D000001:Calcimycin; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate