Diverse Regulation of the CreA Carbon Catabolite Repressor in Aspergillus nidulans

• Grant number: 16/06695-9
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: July 01, 2016
• End date: December 31, 2016
• Field of knowledge: Biological Sciences - Microbiology - Biology and Physiology of Microorganisms
• Principal Investigator: Gustavo Henrique Goldman
• Grantee: Gustavo Henrique Goldman
• Host Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Carbon catabolite repression (CCR) is a process that selects the energetically most favourable carbon source in an environment. CCR represses the utilization of less favourable carbon sources when a better source is available. Glucose is the preferential carbon source for most microorganisms as it is rapidly metabolised generating quick energy for growth. In the filamentous fungusAspergillus nidulans, CCR is mediated by the transcription factor CreA, a C2H2 finger domain DNA binding protein. The aim of this work was to investigate the regulation of CreA and characterise its functionally distinct protein domains. CreA is partially dependent on de novo protein synthesis and is regulated in part by ubiquitination. CreC, the scaffold protein in the CreB/CreC deubiquitination (DUB) complex, is essential for CreA function and stability. Deletion of select protein domains in CreA resulted in persistent nuclear localization and target gene repression. A region in CreA conserved between theAspergilliandT. reeseiwas identified as essential for growth on various carbon, nitrogen and lipid sources. In addition a role of CreA in amino acid transport and nitrogen assimilation was observed. Taken together, this study describes previously unidentified functions of this important transcription factor. These novel functions serve as a basis for additional research in fungal carbon metabolism with the potential aim to improve fungal industrial applications. (AU)