title: Gel mobility shift scanning of pectin-inducible promoter from Penicillium griseoroseum reveals the involvement of a CCAAT element in the expression of a polygalacturonase gene.
abstract: Previous reports have described pgg2, a polygalacturonase-encoding gene of Penicillium griseoroseum, as an attractive model for transcriptional regulation studies, due to its high expression throughout several in vitro growth conditions, even in the presence of non-inducing sugars such as sucrose. A search for regulatory motifs in the 5' upstream regulatory sequence of pgg2 identified a putative CCAAT box that could justify this expression profile. This element, located 270 bp upstream of the translational start codon, was tested as binding target for regulatory proteins. Analysis of a 170 bp promoter fragment by electrophoretic mobility shift assay (EMSA) with nuclear extracts prepared from mycelia grown in pectin-containing culture medium revealed a high mobility complex that was subsequently confirmed by analyzing it with a double-stranded oligonucleotide spanning the CCAAT motif. A substitution in the core sequence for GTAGG partially abolished the formation of specific complexes, showing the involvement of the CCAAT box in the regulation of the polygalacturonase gene studied.
authors.affiliation: Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Viçosa, MG Brazil.
authors.forename: Andréa de O B
authors.initials: Ade O
authors.lastname: Ribon
authors.forename: João Batista
authors.initials: JB
authors.lastname: Ribeiro
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Gonçalves
authors.forename: Marisa V
authors.initials: MV
authors.lastname: de Queiroz
authors.forename: Elza F
authors.initials: EF
authors.lastname: de Araújo