title: Ovine HSP90AA1 gene promoter: functional study and epigenetic modifications.
abstract: When environmental temperatures exceed a certain threshold, the upregulation of the ovine HSP90AA1 gene is produced to cope with cellular injuries caused by heat stress. It has been previously pointed out that several polymorphisms located at the promoter region of this gene seem to be the main responsible for the differences in the heat stress response observed among alternative genotypes in terms of gene expression rate. The present study, focused on the functional study of those candidate polymorphisms by electrophoretic mobility shift assay (EMSA) and in vitro luciferase expression assays, has revealed that the observed differences in the transcriptional activity of the HSP90AA1 gene as response to heat stress are caused by the presence of a cytosine insertion (rs397514115) and a C to G transversion (rs397514116) at the promoter region. Next, we discovered the presence of epigenetic marks at the promoter and along the gene body founding an allele-specific methylation of the rs397514116 mutation in DNA extracted from blood samples. This regulatory mechanism interacts synergistically to modulate gene expression depending on environmental circumstances. Taking into account the results obtained, it is suggested that the transcription of the HSP90AA1 ovine gene is regulated by a cooperative action of transcription factors (TFs) whose binding sites are polymorphic and where the influence of epigenetic events should be also taken into account.
authors.affiliation: INIA, Carretera de La Coruña Km. 7.5, 28040, Madrid, Spain.
authors.forename: Judit
authors.initials: J
authors.lastname: Salces-Ortiz
authors.affiliation: INIA, Carretera de La Coruña Km. 7.5, 28040, Madrid, Spain. gverdejo@inia.es.
authors.forename: Carmen
authors.initials: C
authors.lastname: González
authors.affiliation: Systems Biology Ireland, UCD, Belfield, Dublin 4, Dublin.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Bolado-Carrancio
authors.affiliation: Facultad de Medicina, Universidad de Cantabria, 39005, Santander, Spain.
authors.forename: Jose Carlos
authors.initials: JC
authors.lastname: Rodríguez-Rey
authors.affiliation: Unidad de Tecnología en Producción Animal, CITA, 59059, Zaragoza, Spain.
authors.forename: Jorge H
authors.initials: JH
authors.lastname: Calvo
authors.affiliation: INIA, Carretera de La Coruña Km. 7.5, 28040, Madrid, Spain.
authors.forename: Rubén
authors.initials: R
authors.lastname: Muñoz
authors.affiliation: INIA, Carretera de La Coruña Km. 7.5, 28040, Madrid, Spain.
authors.forename: M Magdalena
authors.initials: MM
authors.lastname: Serrano
mesh_terms: D000818:Animals; D019175:DNA Methylation / Q000235:genetics; D024202:Electrophoretic Mobility Shift Assay; D005838:Genotype; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012756:Sheep
chemical_list: D018841:HSP90 Heat-Shock Proteins
keywords: Allele-specific methylation; EMSA; Epigenetic marks; HSP90AA1; Luciferase; Polymorphisms; Sheep