Chromatin mapping identifies BasR, a key regulator of bacteria-triggered production of fungal secondary metabolites

Abstract

The eukaryotic epigenetic machinery can be modified by bacteria to reprogram the response of eukaryotes during their interaction with microorganisms. We discovered that the bacterium Streptomyces rapamycinicus triggered increased chromatin acetylation and thus activation of the silent secondary metabolism ors gene cluster in the fungus Aspergillus nidulans. Using this model, we aim understanding mechanisms of microbial communication based on bacteria-triggered chromatin modification. Using genome-wide ChIP-seq analysis of acetylated histone H3, we uncovered the unique chromatin landscape in A. nidulans upon co-cultivation with S. rapamycinicus and relate changes in the acetylation to that in the fungal transcriptome. Differentially acetylated histones were detected in genes involved in secondary metabolism, in amino acid and nitrogen metabolism, in signaling, and encoding transcription factors. Further molecular analyses identified the Myb-like transcription factor BasR as the regulatory node for transduction of the bacterial signal in the fungus and show its function is conserved in other Aspergillus species.

Monasone Naphthoquinone Biosynthesis and Resistance in Monascus Fungi

“…The evolution of the ability to synthesize specialized "secondary" metabolites is considered to have been crucial for the survival and diversification of fungal species (11,25). Monascus spp.…”

“…Secondary metabolite natural products are often produced as allelochemicals, and as such, their production is often triggered by interactions of the producer with other microorganisms or plant and animal hosts (25). Cocultivation of microorganisms has also been applied in the laboratory to elicit the biosynthesis of novel SMs or to promote the production of known SMs (31).…”

Cryptic Chemical Communication: Secondary Metabolic Responses Revealed by Microbial Co‐culture

“…genome, the groups found that only the DgcnE deletion mutant almost lost its ability to produce OA and lecanoric acid while co-cultured with S. rapamycinicus. [30] Analysis has been completed on 890 putative transcription factor-encoding genes with various H3K9ac modifications, and this has confirmed that the basR gene is involved in the activationo ft he ors cluster upon co-cultivation by RT-qPCR analysis, gene deletion, and overexpression.M oreover,t he transcriptional level of basR was drastically down-regulated in the DgcnE mutant, indicating that GcnE-catalyzed acetylation is requiredf or basR expression. [28] The metabolic profile of the DadaB strain, which is ad eletion mutant of another essential subunit AdaB in the SAGA/ADA complex, was similar to the DgcnE mutant.…”

“…Recently, the latest progress of this research is the identification of an unknown transcription factor BasR (also called AN7174), which acts as a key regulatory node for coupling the extracellular actinobacterial contact signal and secondary metabolic regulation in A. nidulans . Analysis has been completed on 890 putative transcription factor‐encoding genes with various H3K9ac modifications, and this has confirmed that the basR gene is involved in the activation of the ors cluster upon co‐cultivation by RT‐qPCR analysis, gene deletion, and overexpression.…”

Bioinformatic Analysis of MYB Transcription Factors in <i>Fusarium graminearum</i>

“…In branch I, F. graminearum FgMYB12, FgMYB13, FgFlbD and FgMYB06 locate in the same small branch with Arabidopsis thaliana ATMYB2 (Dubos et al, 2010), Zea mays ZmybC1 (Dubos et al, 2010), Homo sapiens c-MYB (Zhao et al, 2019), Avian myeloblastosis virus v-myb (Klempnauer et al, 1982), Magnaporthe oryzae MoMyb1 (Dong et al, 2018) and Aspergillus fumigatus FlbD (Arratia-Quijada et al, 2012) (blue area in Figure 5), suggesting that they have a close relationship. In addition, F. graminearum FgMYB04, FgMYB05, Molecular Pathogens 2020, Vol.11, No.1, 1-8 http://microbescipublisher.com/index.php/mp MYT1 and MYT3 locate in another small branch with Aspergillus nidulans BasR (Fischer et al, 2018) and Acremonium chrysogenum AcMybA (Wang et al, 2018) (Figure 5 red) Area), which means that they have a close relationship.…”