Regulation of parathyroid hormone-related protein gene expression in murine keratinocytes by E1A isoforms: a role for basal promoter and Ets-1 site.
PTHrP gene expression was evaluated in a murine keratinocyte line, Pam 212K, transformed with E1A and ras. We found that the 12S-E1A oncogene, with or without ras transformation, markedly reduced PTHrP mRNA expression. Using transient transfection assays, we found that the 12S isoform repressed activity from a 5'PTHrP-driven reporter gene. E1A-induced repression of PTHrP reporter constructs appears to be mediated by sequences within minimal promoter region. The 13S-E1A isoform did not repress PTHrP reporter gene activity, and a 13S-deletion mutant that lacked the repressor domains activated a subset of reporter constructs. Mutation of an Ets-1 binding site upstream of the basal promoter substantially decreased activation of reporter constructs by this 13S-deletion mutant. These findings suggest that the E1A oncoprotein may serve as a model for both activation and repression of PTHrP gene expression.
Foley
J
J
Department of Medicine, Yale University School of Medicine, New Haven, CT 06520, USA. jgfoley@indiana.edu
Wysolmerski
J J
JJ
Missero
C
C
King
C S
CS
Philbrick
W M
WM
D017500:Adenovirus E1A Proteins / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002461:Cell Line, Transformed; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D011905:Genes, ras; D015603:Keratinocytes / Q000378:metabolism*; D008156:Luciferases / Q000235:genetics; D051379:Mice; D010281:Parathyroid Hormone / Q000235:genetics; D044162:Parathyroid Hormone-Related Protein; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D011506:Proteins / Q000235:genetics*; D050784:Proto-Oncogene Protein c-ets-1; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D050783:Proto-Oncogene Proteins c-ets; D012333:RNA, Messenger / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
D017500:Adenovirus E1A Proteins; C494042:Ets1 protein, mouse; D010281:Parathyroid Hormone; D044162:Parathyroid Hormone-Related Protein; D020033:Protein Isoforms; D011506:Proteins; D050784:Proto-Oncogene Protein c-ets-1; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D012333:RNA, Messenger; D014157:Transcription Factors; D008156:Luciferases