title: Characterisation of the heat shock factor of the human thermodimorphic pathogen Paracoccidioides lutzii.
abstract: Thermodimorphic fungi include most causative agents of systemic mycoses, but the molecular mechanisms that underlie their defining trait, i.e. the ability to shift between mould and yeast on temperature change alone, remain poorly understood. We hypothesised that the heat shock factor (Hsf), a protein that evolved to sense thermal stimuli quickly, might play a role in this process in addition to the known regulator Drk1 and the Ryp proteins. To test this hypothesis, we characterised the Hsf from the thermodimorph Paracoccidioides lutzii (formerly Paracoccidioides brasiliensis isolate 01). We show in the present work that PlHsf possesses regulatory domains that are exclusive of the Eurotiomycetidae family, suggesting evolutionary specialisation; that it can successfully rescue the otherwise lethal loss of the native protein of Saccharomyces cerevisiae; and that its DNA-binding domain is able to recognise regulatory elements from the promoters of both Drk1 and Ryp1. An in silico screening of all 1 kb sequences upstream of P. lutzii ORFs revealed that 7% of them possess a heat shock element. This is the first description of a heat shock factor in a thermodimorphic fungus.
authors.affiliation: Departamento de Biologia Celular, Universidade de Brasília, 70910-900 Brasília, DF, Brazil.
authors.forename: Hugo Costa
authors.initials: HC
authors.lastname: Paes
authors.forename: Thiago Machado
authors.initials: TM
authors.lastname: Mello-de-Sousa
authors.forename: Larissa
authors.initials: L
authors.lastname: Fernandes
authors.forename: Marcus de Melo
authors.initials: Mde M
authors.lastname: Teixeira
authors.forename: Rafael de Oliveira
authors.initials: Rde O
authors.lastname: Melo
authors.forename: Lorena da Silveira
authors.initials: Lda S
authors.lastname: Derengowski
authors.forename: Fernando Araripe Gonçalves
authors.initials: FA
authors.lastname: Torres
authors.forename: Maria Sueli Soares
authors.initials: MS
authors.lastname: Felipe
mesh_terms: D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000145:classification / Q000235:genetics; D019143:Evolution, Molecular; D006360:Heat-Shock Proteins / Q000145:classification / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D010228:Paracoccidioides / Q000235:genetics* / Q000502:physiology; D010229:Paracoccidioidomycosis / Q000382:microbiology*; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D029701:Saccharomyces cerevisiae Proteins / Q000145:classification / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013696:Temperature; D014157:Transcription Factors / Q000145:classification / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; C067168:HSF1 protein, S cerevisiae; D006360:Heat-Shock Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors