Functional Characterization of Sugar Transporter CRT1 Reveals Differential Roles of Its C-Terminal Region in Sugar Transport and Cellulase Induction in Trichoderma reesei

Wang, Zhixing; Yang, Renfei; Lv, Wenhao; Zhang, Weixin; Meng, Xiangfeng; Liu, Weifeng

doi:10.1128/spectrum.00872-22

Cited by 5 publications

(21 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These experiments have helped to separate nutrient sensing from substrate transport, and indicate that MtLat-1 protein serves as a transceptor, which might sense and transduce molecular signal of l -arabinose, one of the end products of hemicellulose degradation, to repress the induction of hemicellulase genes. The role of transceptor in the induction of genes involved in plant biomass degradation has also been demonstrated for CDT-1/2 in N. crassa and Crt1 in T. reesei [ 9 , 52 ].…”

Section: Discussionmentioning

confidence: 99%

The arabinose transporter MtLat-1 is involved in hemicellulase repression as a pentose transceptor in Myceliophthora thermophila

Zhi-qiang

Xue

et al. 2023

Biotechnol Biofuels

View full text Add to dashboard Cite

Background Filamentous fungi possess an array of secreted enzymes to depolymerize the structural polysaccharide components of plant biomass. Sugar transporters play an essential role in nutrient uptake and sensing of extracellular signal molecules to inhibit or trigger the induction of lignocellulolytic enzymes. However, the identities and functions of transceptors associated with the induction of hemicellulase genes remain elusive. Results In this study, we reveal that the l-arabinose transporter MtLat-1 is associated with repression of hemicellulase gene expression in the filamentous fungus Myceliophthora thermophila. The absence of Mtlat-1 caused a decrease in l-arabinose uptake and consumption rates. However, mycelium growth, protein production, and hemicellulolytic activities were markedly increased in a ΔMtlat-1 mutant compared with the wild-type (WT) when grown on arabinan. Comparative transcriptomic analysis showed a different expression profile in the ΔMtlat-1 strain from that in the WT in response to arabinan, and demonstrated that MtLat-1 was involved in the repression of the main hemicellulase-encoding genes. A point mutation that abolished the l-arabinose transport activity of MtLat-1 did not impact the repression of hemicellulase gene expression when the mutant protein was expressed in the ΔMtlat-1 strain. Thus, the involvement of MtLat-1 in the expression of hemicellulase genes is independent of its transport activity. The data suggested that MtLat-1 is a transceptor that senses and transduces the molecular signal, resulting in downstream repression of hemicellulolytic gene expression. MtAra-1 protein directly regulated the expression of Mtlat-1 by binding to its promoter region. Transcriptomic profiling indicated that the transcription factor MtAra-1 also plays an important role in expression of arabinanolytic enzyme genes and l-arabinose catabolism. Conclusions M. thermophila MtLat-1 functions as a transceptor that is involved in l-arabinose transport and signal transduction associated with suppression of the expression of hemicellulolytic enzyme-encoding genes. The data presented in this study add to the models of the regulation of hemicellulases in filamentous fungi.

show abstract

Section: Discussionmentioning

confidence: 99%

The arabinose transporter MtLat-1 is involved in hemicellulase repression as a pentose transceptor in Myceliophthora thermophila

Zhi-qiang

Xue

et al. 2023

Biotechnol Biofuels

View full text Add to dashboard Cite

show abstract

“…Previously, the deletion of these factors was reported to cause loss or reduction of cellulase expression 38 – 40 , 45 . These factors were also affected by enhanced expression of XYR1 and ACE3 (for example, crt1 is regulated by ACE3 38 , 47 ). This suggested that the effect of co-expression of XYR1 V821F with these factors may not have occurred because sufficient amounts of these factors were already upregulated by the constitutive expression of mutated XYR1 V821F and subsequent upregulation of ACE3 (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…Previously, the deletion of these factors was reported to cause loss or reduction of cellulase expression [38][39][40]45 . These factors were also affected by enhanced expression of XYR1 and ACE3 (for example, crt1 is regulated by ACE3 38,47 ). This suggested that the effect of co-expression www.nature.com/scientificreports/ production (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…Recently, CRT1 was validated to transport lactose, cellobiose, glucose, and soporose 46 . In addition, when XYR1 is overexpressed under glucose-containing conditions, crt1 transcription was maintained at a relatively low level 47 .…”

Section: Introductionmentioning

confidence: 99%

“…www.nature.com/scientificreports/ when XYR1 is overexpressed under glucose-containing conditions, crt1 transcription was maintained at a relatively low level 47 . BGLR, a β-glucosidase activator, is a transcription factor having a Zn(II) 2 -Cys 6 -type DNA-binding domain 39 .…”

mentioning

confidence: 99%

See 2 more Smart Citations

Inducer-free cellulase production system based on the constitutive expression of mutated XYR1 and ACE3 in the industrial fungus Trichoderma reesei

Arai

Ichinose

Shibata

et al. 2022

Sci Rep

View full text Add to dashboard Cite

Trichodermareesei is a widely used host for producing cellulase and hemicellulase cocktails for lignocellulosic biomass degradation. Here, we report a genetic modification strategy for industrial T.reesei that enables enzyme production using simple glucose without inducers, such as cellulose, lactose and sophorose. Previously, the mutated XYR1V821F or XYR1A824V was known to induce xylanase and cellulase using only glucose as a carbon source, but its enzyme composition was biased toward xylanases, and its performance was insufficient to degrade lignocellulose efficiently. Therefore, we examined combinations of mutated XYR1V821F and constitutively expressed CRT1, BGLR, VIB1, ACE2, or ACE3, known as cellulase regulators and essential factors for cellulase expression to the T.reesei E1AB1 strain that has been highly mutagenized for improving enzyme productivity and expressing a ß-glucosidase for high enzyme performance. The results showed that expression of ACE3 to the mutated XYR1V821F expressing strain promoted cellulase expression. Furthermore, co-expression of these two transcription factors also resulted in increased productivity, with enzyme productivity 1.5-fold higher than with the conventional single expression of mutated XYR1V821F. Additionally, that productivity was 5.5-fold higher compared to productivity with an enhanced single expression of ACE3. Moreover, although the DNA-binding domain of ACE3 had been considered essential for inducer-free cellulase production, we found that ACE3 with a partially truncated DNA-binding domain was more effective in cellulase production when co-expressed with a mutated XYR1V821F. This study demonstrates that co-expression of the two transcription factors, the mutated XYR1V821F or XYR1A824V and ACE3, resulted in optimized enzyme composition and increased productivity.

show abstract

Current genetic strategies to investigate gene functions in Trichoderma reesei

Liu

Tang

et al. 2023

Microb Cell Fact

View full text Add to dashboard Cite

The filamentous fungus Trichoderma reesei (teleomorph Hypocrea jecorina, Ascomycota) is a well-known lignocellulolytic enzymes-producing strain in industry. To increase the fermentation titer of lignocellulolytic enzymes, random mutagenesis and rational genetic engineering in T. reesei were carried out since it was initially found in the Solomon Islands during the Second World War. Especially the continuous exploration of the underlying regulatory network during (hemi)cellulase gene expression in the post-genome era provided various strategies to develop an efficient fungal cell factory for these enzymes’ production. Meanwhile, T. reesei emerges competitiveness potential as a filamentous fungal chassis to produce proteins from other species (e.g., human albumin and interferon α-2b, SARS-CoV-2 N antigen) in virtue of the excellent expression and secretion system acquired during the studies about (hemi)cellulase production. However, all the achievements in high yield of (hemi)cellulases are impossible to finish without high-efficiency genetic strategies to analyze the proper functions of those genes involved in (hemi)cellulase gene expression or secretion. Here, we in detail summarize the current strategies employed to investigate gene functions in T. reesei. These strategies are supposed to be beneficial for extending the potential of T. reesei in prospective strain engineering.

show abstract

Functional Characterization of Sugar Transporter CRT1 Reveals Differential Roles of Its C-Terminal Region in Sugar Transport and Cellulase Induction in Trichoderma reesei

Abstract: The lignocellulose-degrading fungus T. reesei has been widely used in industrial cellulases production. Understanding the precise cellulase gene regulatory network is critical for its genetic engineering to enhance the mass production of cellulases.

Cited by 5 publications

References 56 publications

The arabinose transporter MtLat-1 is involved in hemicellulase repression as a pentose transceptor in Myceliophthora thermophila

The arabinose transporter MtLat-1 is involved in hemicellulase repression as a pentose transceptor in Myceliophthora thermophila

Inducer-free cellulase production system based on the constitutive expression of mutated XYR1 and ACE3 in the industrial fungus Trichoderma reesei

Current genetic strategies to investigate gene functions in Trichoderma reesei

Contact Info

Product

Resources

About