Paradoxical Activation of a Type VI Secretion System Phospholipase Effector by Its Cognate Immunity Protein.

ABSTRACT: Type VI secretion systems (T6SSs) deliver cytotoxic effector proteins into target bacteria and eukaryotic host cells. Antibacterial effectors are invariably encoded with cognate immunity proteins that protect the producing cell from self-intoxication. Here, we identify transposon insertions that disrupt the tli immunity gene of Enterobacter cloacae and induce autopermeabilization through unopposed activity of the Tle phospholipase effector. This hyperpermeability phenotype is T6SS dependent, indicating that the mutants are intoxicated by Tle delivered from neighboring sibling cells rather than by internally produced phospholipase. Unexpectedly, an in-frame deletion of tli does not induce hyperpermeability because Δtli null mutants fail to deploy active Tle. Instead, th

SUBMITTER: Jensen SJ 

PROVIDER: S-EPMC10294671 | biostudies-literature | 2023 Jun

REPOSITORIES: biostudies-literature