title: Transcriptional profiling reveals genes in the human pathogen Trichophyton rubrum that are expressed in response to pH signaling.
abstract: Trichophyton rubrum is a dermatophyte that infects human skin and nails. Its growth on keratin as its carbon source shifts the ambient pH from acidic to alkaline, which may be an efficient strategy for its successful infection and maintenance in the host. In this study, we used suppression subtractive hybridization to identify genes preferentially expressed in T. rubrum incubated at either pH 5.0 or pH 8.0. The functional grouping of the 341 overexpressed unigenes indicated proteins putatively involved in diverse cellular processes, such as membrane remodeling, cellular transport, metabolism, cellular protection, fungal pathogenesis, gene regulation, interaction with the environment, and iron uptake. Although the basic metabolic machinery identified under both growth conditions seems to be functionally similar, distinct genes are upregulated at acidic or alkaline pHs. We also isolated a large number of genes of unknown function, probably unique to T. rubrum or dermatophytes. Interestingly, the transcriptional profiling of several genes in a pacC(-) mutant suggests that, in T. rubrum, the transcription factor PacC has a diversity of metabolic functions, in response to either acidic or alkaline ambient pH.
authors.affiliation: Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, 14049-900 Ribeirão Preto, SP, Brazil.
authors.forename: Henrique C S
authors.initials: HC
authors.lastname: Silveira
authors.forename: Diana E
authors.initials: DE
authors.lastname: Gras
authors.forename: Rodrigo A
authors.initials: RA
authors.lastname: Cazzaniga
authors.forename: Pablo R
authors.initials: PR
authors.lastname: Sanches
authors.forename: Antonio
authors.initials: A
authors.lastname: Rossi
authors.forename: Nilce M
authors.initials: NM
authors.lastname: Martinez-Rossi
mesh_terms: D003001:Cloning, Molecular; D018076:DNA, Complementary; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007633:Keratins / Q000378:metabolism; D009154:Mutation; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014249:Trichophyton / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D004271:DNA, Fungal; D005656:Fungal Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger; D014157:Transcription Factors; D007633:Keratins