Research
Title: | Retroposition of the Long Transcript from Multiexon IFN-beta Homologs in Ancestry Vertebrate Gave Rise to the Proximal Transcription Elements of Intronless IFN-beta Promoter in Humans |
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First author: | Chen, Shan Nan; Gan, Zhen; Nie, Pin |
Journal: | JOURNAL OF IMMUNOLOGY |
Years: | 2021 |
DOI: | 10.4049/jimmunol.2100092 |
Abstract: | IFN-beta is a unique member of type I IFN in humans and contains four positive regulatory domains (PRDs), I-II-III-IV, in its promoter, which are docking sites for transcription factors IFN regulatory factor (IRF) 3/7, NF-kappa B, IRF3/7, and activating transcription factor 2/Jun proto-oncogene, respectively. In chicken IFN-beta and zebrafish IFN phi 1 promoters, a conserved PRD or PRD-like sequences have been reported. In this study, a type I IFN gene, named as xl-IFN1 in the amphibian model Xenopus laevis, was found to contain similar PRD-like sites, IV-III/I-II, in its promoter, and these PRD-like sites were proved to be functionally responsive to activating transcription factor 2/Jun proto-oncogene, IRF3/IRF7, and p65, respectively. The xl-IFN1, as IFNu1 in zebrafish, was transcribed into a long and a short transcript, with the long transcript containing all of the transcriptional elements, including PRD-like sites and TATA box in its proximal promoter. A retroposition model was then proposed to explain the transcriptional conservation of IFNu1, xl-IFN1, and IFN-beta in chicken and humans. |