Journal Article

Identification of new signalling peptides through a genome-wide survey of 250 fungal secretomes

Le Marquer, Morgane, Savelli, Bruno, Roux, Christophe, San Clemente, Hélène, Frei dit Frey, Nicolas

2019

Overview

Background Many small peptides regulate eukaryotic cell biology. In fungi, some of these peptides are produced after KEX2 protease activity on proteins displaying repetitions of identical or nearly identical motifs. Following this endoprotease activity, peptides are released in the extracellular space. This type of protein maturation is involved in the production of the α-type sexual pheromone in Ascomycota. In other cases, this processing allows the production of secreted peptides regulating fungal cell wall structure or acting as mycotoxins. In this work, we report for the first time a genome-wide search of KE X2-processed repeat p roteins that we call KEPs. We screened the secreted proteins of 250 fungal species to compare their KEP repertoires with regard to their lifestyle, morphology or lineage. Results Our analysis points out that nearly all fungi display putative KEPs, suggesting an ancestral origin common to all opisthokonts. As expected, our pipeline identifies mycotoxins but also α-type sexual pheromones in Ascomycota that have not been explored so far, and unravels KEP-derived secreted peptides of unknown functions. Some species display an expansion of this class of proteins. Interestingly, we identified conserved KEPs in pathogenic fungi, suggesting a role in virulence. We also identified KEPs in Basidiomycota with striking similarities to Ascomycota α-type sexual pheromones, suggesting they may also play alternative roles in unknown signalling processes. Conclusions We identified putative, new, unexpected secreted peptides that fall into different functional categories: mycotoxins, hormones, sexual pheromones, or effectors that promote colonization during host-microbe interactions. This wide survey will open new avenues in the field of small-secreted peptides in fungi that are critical regulators of their intimate biology and modulators of their interaction with the environment.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Amino Acid Sequence / Amino acids / Animal Genetics and Genomics / Ascomycota / Ascomycota - classification / Ascomycota - genetics / Ascomycota - metabolism / Basidiomycota - classification / Basidiomycota - genetics / Basidiomycota - metabolism / Bioinformatics / Biology / Biomedical and Life Sciences / Cell walls / Cells (Biology) / Colonization / Effector / Eukaryote microbial genomics / Eukaryotes / Fungal Proteins - genetics / Fungal Proteins - metabolism / Fungi / Fungi - classification / Fungi - genetics / Fungi - metabolism / Genome, Fungal - genetics / Genome-wide association studies / Genomes / Genomics / Hormones / KEX2 / Life Sciences / Mating Factor - genetics / Mating Factor - metabolism / Microarrays / Microbial Genetics and Genomics / Modulators / Morphology / Mycotoxin / Mycotoxins / Peptides / Pheromones / Phylogeny / Plant Genetics and Genomics / Proteases / Protein Sorting Signals - genetics / Proteins / Proteomics / Regulators / Research Article / Secreted peptide / Secretome / Sex pheromone / Signal peptides / Signaling / Vegetal Biology / Virulence