title: The Relation Between Promoter Chromatin Status, Xyr1 and Cellulase Ex-pression in Trichoderma reesei.
abstract: The ascomycete Trichoderma reesei is used for the production of plant cell wall-degrading enzymes in industrial scale. The interplay of the transactivator Xyr1 and the repressor Cre1 mainly regulates the expression of these enzymes. During induc-ing conditions, such as in the presence of sophorose, the transcription of the two major cellulase-encoding genes, cbh1 and cbh2, is activated as well as the expression of xyr1. In the presence of D-glucose carbon catabolite repression mediated by Cre1 takes place and the expression of Xyr1 and the plant cell wall-degrading enzymes is down-regulated. In this study we compare the chromatin status of xyr1, cbh1, and cbh2 promoters in the wild-type strain and the Cre1-deficient strain Rut-C30. Chromatin rearrangement occurs in the xyr1 promoter during induction on sophorose. Chromatin opening and protein-DNA interactions in the xyr1 promoter were detected especially in a region located 0.9 kb upstream the translation start co-don, which bears several putative Cre1-binding sites and a CCAAT-box. Moreover, the xyr1 promoter is overall more acces-sible in a cre1-truncated background, no matter which carbon source is present. This makes the xyr1 regulatory sequence a good target for promoter engineering aiming at the enhancement of cellulase production.
authors.affiliation: Department for Biotechnology and Microbiology, TU Wien, Vienna, Austria;
authors.forename: Thiago M
authors.initials: TM
authors.lastname: Mello-de-Sousa
authors.affiliation: Department for Biotechnology and Microbiology, TU Wien, Vienna, Austria;
authors.forename: Alice
authors.initials: A
authors.lastname: Rassinger
authors.affiliation: Department for Biotechnology and Microbiology, TU Wien, Vienna, Austria;
authors.forename: Christian
authors.initials: C
authors.lastname: Derntl
authors.affiliation: Department of Genetics and Morphology, Institute of Biological Sciences, University of Brasilia, Brasília-DF, Brazil.
authors.forename: Marcio J
authors.initials: MJ
authors.lastname: Poças-Fonseca
authors.affiliation: Department for Biotechnology and Microbiology, TU Wien, Vienna, Austria;
authors.forename: Robert L
authors.initials: RL
authors.lastname: Mach
authors.affiliation: Department for Biotechnology and Microbiology, TU Wien, Vienna, Austria;
authors.forename: Astrid R
authors.initials: AR
authors.lastname: Mach-Aigner
keywords: Cellulases; Chromatin; Promoter; Rut-C30; Trichoderma reesei; Xyr1.