Metabolic Integration of Bacterial Endosymbionts through Antimicrobial Peptides. Issue 9 (September 2017)

• Record Type: Journal Article
• Authors: Mergaert, Peter; Kikuchi, Yoshitomo; Shigenobu, Shuji; Nowack, Eva C.M.
• Is Part Of: Trends in microbiology. Volume 25:Issue 9(2017)
• Page Start: 703
• Page End: 712
• Publication Date: 2017-09
• Subjects: endosymbiosis -- metabolic integration -- antimicrobial peptide -- genome reduction -- solute transport; Microbiology -- Periodicals; Infection -- Periodicals; Virulence (Microbiology) -- Periodicals; Infection -- Periodicals; Microbiology -- Periodicals; Virulence -- Periodicals; Microbiologie -- Périodiques; Infection -- Périodiques; Virulence (Microbiologie) -- Périodiques; Infection; Microbiology; Virulence (Microbiology); 579
• DOI: 10.1016/j.tim.2017.04.007
• Languages: English
• ISSNs: 0966-842X

Abstract

Abstract : Antimicrobial peptides (AMPs) are massively produced by eukaryotic hosts during symbiotic interactions with bacteria. Among other roles, these symbiotic AMPs have the capacity to permeabilize symbiont membranes and facilitate metabolite flow across the host–symbiont interface. We propose that an ancestral role of these peptides is to facilitate metabolic exchange between the symbiotic partners through membrane permeabilization. This function may be particularly critical for integration of endosymbiont and host metabolism in interactions involving bacteria with strongly reduced genomes lacking most small metabolite transporters. Moreover, AMPs could have acted in a similar way at the onset of plastid and mitochondrion evolution, after a host cell took up a bacterium and needed to extract nutrients from it in the absence of dedicated solute transporters. Trends: The intricate metabolic integration of bacterial endosymbionts and their hosts is hard to explain in light of the lack of sufficient small metabolite transporter genes in the reduced endosymbiont genomes. AMPs are best known as effectors of innate immunity but they are also found in symbiotic interactions in which they seem to target endosymbiotic bacteria. We propose that a key function of symbiotic AMPs is the stimulation of metabolite exchange at the symbiont–host interface, a role that is essential in modern symbiotic interactions but that might have also enabled the metabolic integration of the mitochondrion and plastid ancestors. AMP-induced transient membrane failures, combined with regulatory mechanisms of AMP activity, and endosymbiont confinement make the metabolite flux compatible with the maintenance of the proton motive force across the bacterial membrane. Abstract : Video Abstract: