The signaling of genic expression in eukaryotes by carbohydrate: cellulose and glucose and their roles in the expression of the cellulolytic system in microorganisms

• Grant number: 97/05267-0
• Support Opportunities: Research Projects - Thematic Grants
• Start date: October 01, 1997
• End date: March 31, 2003
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal Investigator: Hamza Fahmi Ali El-Dorry
• Grantee: Hamza Fahmi Ali El-Dorry
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant(s): 02/08445-7 - Elucidation of the metabolic fate of glucose in Trichoderma reesei using EST analysis and cDNA microarray: a step towards metabolic engineering of the regulatory networks for anaerobic metabolism for glucose, AR.EXT

Abstract

Carbohydrates can signal alterations in the genetic expression depending on the metabolic state of the cell. As a model for this study cellulolytic microorganisms capable of using cellulose as a source of energy are being used. In the majority of these organisms the cellulose induces the cellulolytic system, the latter being repressed by glucose. The Trichoderma reesei fungus is being used as model. One position supported by experimental evidence singled out mitochondria as a highly sensitive organelle for "feeling” the metabolic state of the cell, functioning as an intermediary between the signal generated by carbohydrate and the nuclear genic expression. In this project there will be detailed analysis of the involvement of mitochondria in the expression of the genes of cellulase, regulated by cellulose and glucose, as well as the promoter of the proteic factors involved in that signaling. In addition, we are introducing another cellulolytic microorganism, an endomycorrhizal fungus, which colonizes the roots of plants in a perfect symbolic association. With this we seek to understand the role of cellulase in the process of root colonization. (AU)