Interactome of Glyceraldehyde-3-Phosphate Dehydrogenase Points to the Existence of Metabolons in Paracoccidioides lutzii.

Kleber Santiago Freitas E Silva,Sébastien Charneau,Raisa Melo Lima,Lilian Cristiane Baeza,Roosevelt Alves Da Silva,Maristela Pereira,Thuany De Moura Cordeiro,Célia Maria De Almeida Soares,Patrícia De Sousa Lima

doi:10.3389/fmicb.2019.01537

Abstract

Paracoccidioides is a dimorphic fungus, the causative agent of paracoccidioidomycosis. The disease is endemic within Latin America and prevalent in Brazil. The treatment is based on azoles, sulfonamides and amphotericin B. The seeking for new treatment approaches is a real necessity for neglected infections. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an essential glycolytic enzyme, well known for its multitude of functions within cells, therefore categorized as a moonlight protein. To our knowledge, this is the first approach performed on the Paracoccidioides genus regarding the description of PPIs having GAPDH as a target. Here, we show an overview of experimental GAPDH interactome in different phases of Paracoccidioides lutzii and an in silico analysis of 18 proteins partners. GAPDH interacted with 207 proteins in P. lutzii. Several proteins bound to GAPDH in mycelium, transition and yeast phases are common to important pathways such as glycolysis and TCA. We performed a co-immunoprecipitation assay to validate the complex formed by GAPDH with triose phosphate isomerase, enolase, isocitrate lyase and 2-methylcitrate synthase. We found GAPDH participating in complexes with proteins of specific pathways, indicating the existence of a glycolytic and a TCA metabolon in P. lutzii. GAPDH interacted with several proteins that undergoes regulation by nitrosylation. In addition, we modeled the GAPDH 3-D structure, performed molecular dynamics and molecular docking in order to identify the interacting interface between GAPDH and the interacting proteins. Despite the large number of interacting proteins, GAPDH has only four main regions of contact with interacting proteins, reflecting its ancestrality and conservation over evolution.

Highlights

Paracoccidioides is a dimorphic fungi and the genus includes species that cause paracoccidioidomycosis (PCM)
Several proteins bound to Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in mycelium, transition and yeast phases are common to important pathways such as glycolysis and TCA
We found GAPDH participating in complexes with proteins of specific pathways, indicating the existence of a glycolytic and a TCA metabolon in P. lutzii

Summary

Introduction

Paracoccidioides is a dimorphic fungi and the genus includes species that cause paracoccidioidomycosis (PCM). The disease is endemic in Latin America and prevalent in Brazil (Brummer et al, 1993). The genus Paracoccidioides comprises five distinct species Paracoccidioides brasiliensis, Paracoccidioides lutzii, Paracoccidioides americana, Paracoccidioides venezuelensis, and Paracoccidioides restrepiensis (Muñoz et al, 2016; Turissini et al, 2017). The mycelium phase grows in the environment or in culture at 22◦C. The fungus undergoes differentiation into the yeast form at 37◦C in culture or within the host lungs and disseminates into several organs (Brummer et al, 1993). The PCM treatment is arduous (Travassos et al, 2008) and the most common drugs used are based on azoles, sulfonamides and amphotericin B and they present a considerable degree of toxicity. The period of treatment can be extended to years in some cases (Bocca et al, 2013)

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Conclusion