title: Protein disulfide isomerase homolog TrPDI2 contributing to cellobiohydrolase production in Trichoderma reesei.
abstract: The majority of the cysteine residues in the secreted proteins form disulfide bonds via protein disulfide isomerase (PDI)-mediated catalysis, stabilizing the enzyme activity. The role of PDI in cellulase production is speculative, as well as the possibility of PDI as a target for improving enzyme production efficiency of Trichoderma reesei, a widely used producer of enzyme for the production of lignocellulose-based biofuels and biochemicals. Here, we report that a PDI homolog, TrPDI2 in T. reesei exhibited a 36.94% and an 11.81% similarity to Aspergillus niger TIGA and T. reesei PDI1, respectively. The capability of TrPDI2 to recover the activity of reduced and denatured RNase by promoting refolding verified its protein disulfide isomerase activity. The overexpression of Trpdi2 increased the secretion and the activity of CBH1 at the early stage of cellulase induction. In addition, both the expression level and redox state of TrPDI2 responded to cellulase induction in T. reesei, providing sustainable oxidative power to ensure cellobiohydrolase maturation and production. The results suggest that TrPDI2 may contribute to cellobiohydrolase secretion by enhancing the capability of disulfide bond formation, which is essential for protein folding and maturation.
authors.affiliation: Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China; University of Chinese Academy Sciences, 19A, Yuquan Road, Beijing 100049, China.
authors.forename: Guokun
authors.initials: G
authors.lastname: Wang
authors.affiliation: Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China.
authors.forename: Pin
authors.initials: P
authors.lastname: Lv
authors.affiliation: Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China.
authors.forename: Ronglin
authors.initials: R
authors.lastname: He
authors.affiliation: Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China.
authors.forename: Haijun
authors.initials: H
authors.lastname: Wang
authors.affiliation: Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China.
authors.forename: Lixian
authors.initials: L
authors.lastname: Wang
authors.affiliation: Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China. Electronic address: zhang_dy@tib.cas.cn.
authors.forename: Dongyuan
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China. Electronic address: chen_sl@tib.cas.cn.
authors.forename: Shulin
authors.initials: S
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D043366:Cellulose 1,4-beta-Cellobiosidase / Q000096:biosynthesis* / Q000737:chemistry; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010802:Phylogeny; D019704:Protein Disulfide-Isomerases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017510:Protein Folding; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014242:Trichoderma / Q000201:enzymology* / Q000235:genetics
chemical_list: D005656:Fungal Proteins; D011994:Recombinant Proteins; D043366:Cellulose 1,4-beta-Cellobiosidase; D019704:Protein Disulfide-Isomerases
keywords: Cellobiohydrolase; Cellulase; Disulfide bond; Protein disulfide isomerase; Trichoderma reesei