Molecular evolution and transcriptional profile of GH3 and GH20 β-N-acetylglucosaminidases in the entomopathogenic fungus Metarhizium anisopliae

Abstract

Cell walls are involved in manifold aspects of fungi maintenance. For several fungi, chitin synthesis, degradation and recycling are essential processes required for cell wall biogenesis; notably, the activity of β-N-acetylglucosaminidases (NAGases) must be present for chitin utilization. For entomopathogenic fungi, such as Metarhizium anisopliae, chitin degradation is also used to breach the host cuticle during infection. In view of the putative role of NAGases as virulence factors, this study explored the transcriptional profile and evolution of putative GH20 NAGases (MaNAG1 and MaNAG2) and GH3 NAGases (MaNAG3 and MaNAG4) identified in M. anisopliae. While MaNAG2 orthologs are conserved in several ascomycetes, MaNAG1 clusters only with Aspergilllus sp. and entomopathogenic fungal species. By contrast, MaNAG3 and MaNAG4 were phylogenetically related with bacterial GH3 NAGases. The transcriptional profiles of M. anisopliae NAGase genes were evaluated in seven culture conditions showing no common regulatory patterns, suggesting that these enzymes may have specific roles during the Metarhizium life cycle. Moreover, the expression of MaNAG3 and MaNAG4 regulated by chitinous substrates is the first evidence of the involvement of putative GH3 NAGases in physiological cell processes in entomopathogens, indicating their potential influence on cell differentiation during the M. anisopliae life cycle.

Phylogenomics of a new fungal phylum reveals multiple waves of reductive evolution across Holomycota

“…Nonetheless, sanchytrids displayed a rich repertoire of carbohydrate-degrading enzymes (Extended Data Figs. 6-10), most of them being likely involved in the degradation of algal cell walls required for their penetration into the host cells 13,82,83 . However, the most important difference between sanchytrids and canonical fungi concerned lipid metabolism, with the steroids and fatty acids metabolism missing in sanchytrids and also in Rozella 9 (Extended Data Fig.…”

“…In some cases, we added the identified sequences to specific protein datasets from previous studies. For cellulases, we updated a previous aphelid dataset 13 , and for the chitin degradation proteins we updated previous datasets of GH20 β-N-acetylhexosaminidase (NAGase) 83 and GH18 chitinase 82 . Proteins were aligned with MAFFT 125 and trimmed from gaps and ambiguously aligned sites using TrimAl 126 with the automated1 algorithm.…”

“…we updated a previous aphelid dataset 13 , and for the chitin degradation proteins we updated previous datasets of GH20 β -N-acetylhexosaminidase (NAGase) 83 and GH18 chitinase 82 . Proteins were aligned with MAFFT 125 and trimmed from gaps and ambiguously aligned sites using…”

Genome-wide DNA methylation analysis of Metarhizium anisopliae during tick mimicked infection condition

“…However, the impact of DNA methylation in the infection process was not evaluated in M. robertsii . In the experiments conducted here, we started to address this problem, employing a mimicked infection condition that has been used before and a saprophytic-like condition as a control [6, 19–21]. Noteworthy, previous results have shown that virulence determinants were up-regulated in the mimicked infection condition [6, 7].…”

Análisis de las investigaciones sobre Metarhizium anisopliae en los últimos 40 años

“…Otra sub-área de investigación de relevancia para este microorganismo es el aspecto molecular. Diversas investigaciones han analizado el rol de varias enzimas (Dextruxinas, MaNAG1, MaNAG2, MaNAG3 y MaNAG4) durante el ciclo de vida del Metarhizium anisopliae (de Oliveira et al, 2018), caracterizado las ribonucleasas tóxicas de este microorganismo como insecticidas potenciales contra ribosomas para el control de vectores de enfermedades (Olombrada et al, 2017), así como la función de algunos genes sobre la adaptación al ambiente de este microorganismo (Zeng et al, 2018) y en su nivel de virulencia (Santos et al, 2017).…”