title: Disruption of Trichoderma reesei cre2, encoding an ubiquitin C-terminal hydrolase, results in increased cellulase activity.
abstract: BACKGROUND
  The filamentous fungus Trichoderma reesei (Hypocrea jecorina) is an important source of cellulases for use in the textile and alternative fuel industries. To fully understand the regulation of cellulase production in T. reesei, the role of a gene known to be involved in carbon regulation in Aspergillus nidulans, but unstudied in T. reesei, was investigated.
  
  
  RESULTS
  The T. reesei orthologue of the A. nidulans creB gene, designated cre2, was identified and shown to be functional through heterologous complementation of a creB mutation in A. nidulans. A T. reesei strain was constructed using gene disruption techniques that contained a disrupted cre2 gene. This strain, JKTR2-6, exhibited phenotypes similar to the A. nidulans creB mutant strain both in carbon catabolite repressing, and in carbon catabolite derepressing conditions. Importantly, the disruption also led to elevated cellulase levels.
  
  
  CONCLUSIONS
  These results demonstrate that cre2 is involved in cellulase expression. Since the disruption of cre2 increases the amount of cellulase activity, without severe morphological affects, targeting creB orthologues for disruption in other industrially useful filamentous fungi, such as Aspergillus oryzae, Trichoderma harzianum or Aspergillus niger may also lead to elevated hydrolytic enzyme activity in these species.
authors: School of Molecular and Biomedical Science, University of Adelaide, Adelaide 5005, Australia.
authors: Jai A
authors: JA
authors: Denton
authors: Joan M
authors: JM
authors: Kelly
mesh_terms: D000595:Amino Acid Sequence; D001234:Aspergillus niger / Q000235:genetics; D001236:Aspergillus oryzae / Q000235:genetics; D002480:Cellulase / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D005816:Genetic Complementation Test; D007218:Industrial Microbiology / Q000379:methods*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010957:Plasmids; D017386:Sequence Homology, Amino Acid; D014161:Transduction, Genetic; D014242:Trichoderma / Q000201:enzymology / Q000235:genetics; D043222:Ubiquitin Thiolesterase / Q000172:deficiency / Q000235:genetics*; D015854:Up-Regulation
chemical_list: D002482:Cellulose; D002480:Cellulase; D043222:Ubiquitin Thiolesterase