Chromatin Immunoprecipitation-DNA sequencing (ChIP-seq) as a tool to identify genes regulated by the MADS Box transcription factor RlmA in Aspergillus fumigatus

• Grant number: 19/03063-0
• Support Opportunities: Scholarships abroad - Research
• Effective date (Start): November 01, 2019
• Effective date (End): October 31, 2020
• Field of knowledge: Biological Sciences - Microbiology - Biology and Physiology of Microorganisms
• Principal Investigator: Iran Malavazi
• Grantee: Iran Malavazi
• Host Investigator: Robert Cramer
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Research place: Dartmouth College, United States

Abstract

Invasive pulmonary aspergillosis (IPA) is the life-threatening form of infection caused by the filamentous fungus Aspergillus fumigatus which affects immunocompromised individuals. The cell wall is essential for the survival of the fungal cell and is a protective barrier against environmental stresses including osmotic damage to the cell. Understanding the mechanisms whereby the fungal cell synthetizes and/or remodels the cell wall is highly relevant considering the high mortality rates which results from the A. fumigatus infection. Our laboratory studies one of the signaling transduction pathways responsible for the synthesis and remodeling of fungal cell wall called the cell wall integrity pathway (CWIP). However, the upstream activation mechanisms and downstream direct effector targets of the CWIP are still largely unknown. This gap in knowledge represents the central premise for this proposal. Previously, we identified the importance of the CWIP apical protein kinase, PkcA and the "MADS box" transcription factor, RlmA. The results indicated that RlmA is required for the transcriptional activation of several genes related to the maintenance of CWI, as well as genes involved in other cellular processes. However, the limitation of transcriptomic analyses is that they are unable to distinguish between genes that are directly or indirectly regulated by a given transcription factor. In this project, we will use Chromatin immunoprecipitation technique coupled to DNA sequencing (ChIP-seq) to obtain a comprehensive analysis of the extent of the cell actions governed by RlmA during cell wall stress. In addition, protein partners of the apical kinase PkcA will be identified through a proteomic approach. Understanding this signaling pathway through a combination of biochemical and genomic approaches will add information about potential cell wall related proteins exploitable as therapeutic targets that are expected to support more effective management of A. fumigatus infections.