title: miR-429 regulation of osmotic stress transcription factor 1 (OSTF1) in tilapia during osmotic stress.
abstract: The Nile tilapia represents an excellent model for osmoregulation study. Osmotic stress transcription factor 1 (OSTF1) identified in tilapia gill epithelium is a critical element of osmosensory signal transduction by means of transcriptional regulation. Thus, tight regulation of OSTF1 level is necessary for tilapia osmotic adaptation. microRNAs (miRNAs), have emerged as a crucial regulator of gene expression at post-transcriptional level. We reasoned that OSTF1 expression could be regulated by miRNAs. By bioinformatics analysis, we identified a putative miR-429 binding site in the OSTF1 mRNA. Interestingly, miR-429 is down-regulated in tilapia upon osmotic stress, consistent with OSTF1 protein up-regulation. miR-429 directly regulates OSTF1 expression by targeting its 3'-UTR, and inhibition of miR-429 substantially increases OSTF1 level in vivo. Moreover, miR-429 loss of function could influence the regulation of plasma osmolality and ion concentration responding to osmotic stress. Taken together, miR-429 is an endogenous regulator of OSTF1 expression, which participates in a regulatory circuit that allows rapid gene program transitions in response to osmotic stress.
authors.affiliation: Key Laboratory of Freshwater Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Biao
authors.initials: B
authors.lastname: Yan
authors.forename: Li-Hui
authors.initials: LH
authors.lastname: Zhao
authors.forename: Jin-Tao
authors.initials: JT
authors.lastname: Guo
authors.forename: Jin-Liang
authors.initials: JL
authors.lastname: Zhao
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D035683:MicroRNAs / Q000378:metabolism*; D009995:Osmosis / Q000502:physiology*; D009997:Osmotic Pressure; D017210:Tilapia / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D020413:3' Untranslated Regions; D029941:Fish Proteins; D035683:MicroRNAs; D014157:Transcription Factors