Transactivation of lung lysozyme expression by Ets family member ESE-1.
Epithelial-specific Ets (ESE) transcription factors, consisting of ESE-1, ESE-2, and ESE-3, are constitutively expressed in distinct epithelia of mucosal tissues, including the lung. Each ESE member exhibits alternative splicing and yields at least two isoforms (a and b) with transcriptional targets largely unidentified. The studies described herein define a novel role for ESE transcription factors in transactivation of the human lysozyme gene (LYZ), an essential component of innate defense in lung epithelia. Of the six ESE isoforms, ESE-1a and ESE-1b transactivated LYZ promoter in reporter gene assays, whereas only ESE-1b dramatically upregulated transcription of endogenous LYZ in both nonpulmonary and pulmonary epithelial cells. Importantly, ESE-1a and ESE-1b could transactivate the LYZ promoter in cultured primary airway epithelial cells. ESE-2 and ESE-3 isoforms were unable to substantially transactivate the lysozyme promoter or upregulate transcription of endogenous LYZ. Two functional consensus Ets sites located in the proximal 130-bp LYZ promoter were responsive to ESE-1b as identified by site-directed mutagenesis and DNA binding assays. Short hairpin RNA attenuation of endogenous ESE-1b mRNA levels in lung epithelia resulted in decreased LYZ transcription. Furthermore, ESE-1 antibody specifically enriched the 130-bp proximal LYZ promoter in chromatin immunoprecipitation analyses. These findings define a novel role for ESE transcription factors in regulating lung innate defense and suggest distinct regulatory functions for ESE family members.
Lei
Wanli
W
Infectious Disease Program, Lovelace Respiratory Research Institute, 2425 Ridgecrest Dr. SE, Albuquerque, NM 87108, USA.
Jaramillo
Richard J
RJ
Harrod
Kevin S
KS
D002478:Cells, Cultured; D047369:Chromatin Immunoprecipitation; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D004848:Epithelium / Q000378:metabolism*; D006801:Humans; D008168:Lung / Q000166:cytology / Q000378:metabolism*; D009113:Muramidase / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D050783:Proto-Oncogene Proteins c-ets; D034622:RNA Interference; D012333:RNA, Messenger; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; C403306:EHF protein, human; C105529:ELF3 protein, human; C116038:ELF5 protein, human; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D012333:RNA, Messenger; D014157:Transcription Factors; D009113:Muramidase