title: UV irradiation upregulates Egr-1 expression at transcription level.
abstract: UVC irradiation rapidly and strongly induces protein expression of the early growth response-1 gene (Egr-1) encoding a transcription factor which may have a protective function against UV damage. In this paper, we further investigate mechanisms responsible for such induction. We show that UVC irradiation also induced Egr-1 mRNA expression, increased transcription rate by nuclear run-on assay and stimulated Egr-1 promoter activity by CAT assay. The Egr-1 mRNA stability remained unchanged in UVC-treated cells. On the other hand, UVC irradiation slightly extended Egr-1 protein half-life. The induction of Egr-1 by UVC was observed in many different cell types. UVA and UVB also strongly induced Egr-1 expression. These results indicate that UVC regulates Egr-1 expression at transcription level. The induction pattern of Egr-1 by UV suggests the importance of Egr-1 in the UV response.
authors.affiliation: Molecular Medicine, Northwest Hospital, Seattle, Washington 98125, USA. rphuang@nwlink.com
authors.forename: R P
authors.initials: RP
authors.lastname: Huang
authors.forename: Y
authors.initials: Y
authors.lastname: Fan
authors.forename: A L
authors.initials: AL
authors.lastname: Boynton
mesh_terms: D016475:3T3 Cells; D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D051766:Early Growth Response Protein 1; D017874:Immediate-Early Proteins; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic / Q000528:radiation effects*; D014466:Ultraviolet Rays; D015854:Up-Regulation
chemical_list: D004268:DNA-Binding Proteins; D051766:Early Growth Response Protein 1; C486109:Egr1 protein, mouse; D017874:Immediate-Early Proteins; D012333:RNA, Messenger; D014157:Transcription Factors