Oral Actinobacteria sense and defend against parasitic epibionts
Bacteria contend with a wide range of antagonistic interactions from neighboring microbes. One widespread but poorly understood threat is posed by Patescibacteria, which proliferate by colonizing host bacteria surfaces and extracting cellular resources. Despite the ubiquity of Patescibacteria in the environment, how hosts defend against these epibionts remains unknown. Here we show that…
Oral Actinobacteria have developed a method to sense and defend against parasitic epibionts, according to recent research. These bacteria face various threats from neighboring microbes, including Patescibacteria, which colonize host bacteria surfaces and extract cellular resources. However, the mechanisms by which hosts defend against these epibionts have been unclear due to the widespread presence of Patescibacteria in the environment.
In this study, researchers discovered that Actinomycetota, a group of Actinobacteria, utilize the Esx secretion system to fend off Patescibacteria. They identified a secreted effector protein that plays a crucial role in this defensive behavior. The researchers also demonstrated that the Esx induction is part of a complex, epibiont-specific response that involves multiple predicted cell surface modifications.
Furthermore, the study revealed that this defensive response occurs at the transcriptional level and is mediated by a previously unknown threat sensing pathway. When activated, this pathway leads to threonine phosphorylation of an FHA domain-containing output protein. Bioinformatic evidence supports the link between this threat sensing pathway and the Esx pathway across Actinomycetales, indicating a functional role for the Esx pathway in defense against epibionts.
These findings help clarify the ecological relationship between Patescibacteria and their hosts, suggesting that it is one of antagonism rather than mutualism.
Written by urgent.news from bioRxiv's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
