title: Intronic promoter-mediated feedback loop regulates bean PvSR2 gene expression.
abstract: Intronic promoter usage is a widespread regulatory mechanism for increasing the diversity of gene expression regulation. However, its trans-acting mechanisms that modulate host gene expression are poorly characterized. We previously showed that bean (Phaseolus vulgaris) stress-related gene 2 (PvSR2) produces a metal-responsive element (MRE)-binding transcription factor (PvMTF-1) by using an intronic promoter. Interestingly, a functional MRE resides within the upstream PvSR2 promoter, implying that PvMTF-1 is likely to regulate its host gene expression via this MRE. Through DNA-protein interaction studies combined with an analysis of expression of PvMTF-1 in bean leaves, we now report that PvMTF-1 binds to this MRE and thereby up-regulates PvSR2 expression, thus constituting a positive regulatory feedback loop. Our findings provide evidence for a trans-acting mechanism of an intronic promoter in host gene expression, hence, adding a new layer of complexity in intronic promoter-mediated gene regulation. This study may also contribute to the understanding of the intron-mediated regulation of gene expression in trans.
authors.affiliation: College of Life Science, Capital Normal University, Beijing 100048, China.
authors.forename: Wanning
authors.initials: W
authors.lastname: Yang
authors.affiliation: College of Life Science, Capital Normal University, Beijing 100048, China.
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Bei
authors.affiliation: College of Life Science, Capital Normal University, Beijing 100048, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Liu
authors.affiliation: College of Life Science, Capital Normal University, Beijing 100048, China. Electronic address: qixiaoting@cnu.edu.cn.
authors.forename: Xiaoting
authors.initials: X
authors.lastname: Qi
mesh_terms: D001665:Binding Sites; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007438:Introns; D027805:Phaseolus / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D019076:Transgenes
chemical_list: D010940:Plant Proteins
keywords: Feedback loop regulation; Intronic promoter; Metal-responsive element; Phaseolus vulgaris; Transcription factor