Details

Autor(en) / Beteiligte

• Mach-Aigner, Astrid R
• Pucher, Marion E
• Steiger, Matthias G
• Bauer, Gudrun E
• Preis, Sonja J
• Mach, Robert L

Titel

Transcriptional Regulation of xyr1, Encoding the Main Regulator of the Xylanolytic and Cellulolytic Enzyme System in Hypocrea jecorina

Ist Teil von

• Applied and Environmental Microbiology, 2008-11, Vol.74 (21), p.6554-6562

Ort / Verlag

Washington, DC: American Society for Microbiology

Erscheinungsjahr

2008

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• In Hypocrea jecorina, Xyr1 (xylanase regulator 1) is the main transcription activator of hydrolase-encoding genes, such as xyn1, xyn2, bxl1, cbh1, cbh2, egl1, and bgl1. Even though Xyr1 mediates the induction signal for all these genes derived from various inducing carbon sources and compounds, xyr1 transcription itself is not inducible by any of these substances. However, cultivation on glucose as the carbon source provokes carbon catabolite repression of xyr1 transcription mediated by Cre1. In addition, xyr1 transcription is repressed by the specific transcription factor Ace1. Moreover, Xyr1 is permanently available in the cell, and no de novo synthesis of this factor is needed for a first induction of xyn1 transcription. The constitutive expression of xyr1 leads to a significant elevation/deregulation of the xyn1, xyn2, and bxl1 transcription compared to what is seen for the parental strain. Overall, the corresponding xylanolytic enzyme activities are clearly elevated in a constitutively xyr1-expressing strain, emphasizing this factor as an auspicious target for genetically engineered strain improvement.