Functional studies of gene regulatory networks in Trichoderma reesei during the cellulases formation

Abstract

The fungus Trichoderma reesei is recognized as an industrial producer of cellulases. These enzymes move a market that grows every year and in the order of millions of dollars. The major cellulase genes are regulated in a coordinated manner according to available carbon source. Expression of these genes can be induced by cellulose and other substances (eg, cellobiose, sophorose and lactose), while glucose acts as a source of repressive carbon. The industrial potential of cellulases led to an investigation of the biochemical properties, three-dimensional structure and mechanism of action of a number of these proteins. Nevertheless, the nature of the inducer, the sensing and transport signaling pathways are elucidated. Therefore, this project proposes the systematic functional study of gene regulation networks of this fungus during the production of cellulases. Efforts will be focused on the elucidation of nutrient sensing by GPCrs, PTH11 and CFEM domain proteins; identification of new sugar transporters by membrane proteomics; identification of new transcription factors involved in the regulation of cellulase expression; functional genomics by CRISPR-Cas9 of differentially expressed candidate genes in the conditions of cellulase production and repression; evaluation of phosphorylation targets by PKA, TMK1 and TMK2 by phosphoproteome studies and finally; the integration of this information to understand the systemic biology of the fungus during the production of cellulases. With the results generated in this project, we intend to contribute to a better understanding of the biology of this important industrial fungus, with a view to the production of metabolic mutants in order to increase the production of cellulases and to reduce production costs that still affect a large part of the obtained biotechnological products from T. reesei. (AU)