A meet-up of AcP and c-di-GMP modulates BldD activity for  development and antibiotic production in actinobacteria
Actinobacteria are ubiquitous bacteria undergoing complex developmental transition coincided with antibiotics production in response to stress or nutrients starvation. This transition is mainly controlled by the interaction between the second messenger c-di-GMP and the master repressor BldD. To date, the upstream factors and the global signal networks that regulate this intriguing cell biological processes still remained unknown. In Saccharopolyspora erythraea, we found that acetyl phosphate (AcP) accumulation resulting from environmental nitrogen stress participated in the regulation of BldD activity through cooperation with c-di-GMP. AcP-induced acetylation of BldD at K11 caused the BldD dimer to fall apart and dissociate from the target DNA, as well as disrupted the signal transduction of c-di-GMP, thus governed both developmental transition and antibiotics production. Meanwhile, practical mutation of BldDK11R bypassing the acetylation regulation could enhance the positive effect of BldD on antibiotics production. Our finding represents an entirely different role of the covalent modification caused by AcP, which integrated with c-di-GMP signal in modulating the activity of BldD for development and antibiotic production coping with environmental stress. This coherent and highly conserved regulatory network might offer new insight into the direct connections from specific regulator to the actinobacteria biological process associated with major morphogenetic event Overall design: ChIP-Seq