title: Effects of clbR overexpression on enzyme production in Aspergillus aculeatus vary depending on the cellulosic biomass-degrading enzyme species.
abstract: ClbR is a Zn(II)2Cys6 transcriptional activator that controls the expression of cellulase-related genes in response to Avicel and cellobiose in Aspergillus aculeatus. A clbR-overexpressing strain (clbR-OE) that expresses the clbR gene at levels sevenfold higher than the control strain sustainably produced xylanolytic and cellulolytic activities during 10-day cultivation of A. aculeatus, enabling synchronization of xylanolytic and cellulolytic activities at a maximum level. However, clbR overexpression did not simultaneously increase levels of all xylanolytic and cellulolytic enzymes. Peptide mass fingerprint analysis revealed markedly increased production of FIa-xylanase in clbR-OE, whereas expression of FIII-avicelase and FII-carboxymethyl cellulase was unaffected and expression of hydrocellulase was lower in clbR-OE than in the control. Northern blot analysis confirmed that these effects of clbR overexpression on enzyme production were mediated at the transcriptional level. These data suggest that ClbR participates in diverse signaling pathways to control the expression of cellulosic biomass-degrading enzymes in A. aculeatus.
authors.affiliation: a Graduate School of Life and Environmental Sciences , Osaka Prefecture University , Osaka , Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Kunitake
authors.forename: Ayano
authors.initials: A
authors.lastname: Kawamura
authors.forename: Shuji
authors.initials: S
authors.lastname: Tani
authors.forename: Shigeo
authors.initials: S
authors.lastname: Takenaka
authors.forename: Wataru
authors.initials: W
authors.lastname: Ogasawara
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Sumitani
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawaguchi
mesh_terms: D001230:Aspergillus / Q000166:cytology / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D018533:Biomass; D002480:Cellulase / Q000096:biosynthesis* / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism*; D043364:Endo-1,4-beta Xylanases / Q000096:biosynthesis* / Q000378:metabolism; D015870:Gene Expression; D015398:Signal Transduction / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D014157:Transcription Factors; D002482:Cellulose; D002480:Cellulase; D043364:Endo-1,4-beta Xylanases
keywords: Aspergillus aculeatus; ClbR; cellulase-related genes; gene regulation