Caulobacterlipid A is conditionally dispensable in the absence of furand in the presence of anionic sphingolipids

Autor: Zik, Justin J., Yoon, Sung Hwan, Guan, Ziqiang, Stankeviciute Skidmore, Gabriele, Gudoor, Ridhi R., Davies, Karen M., Deutschbauer, Adam M., Goodlett, David R., Klein, Eric A., Ryan, Kathleen R.
Zdroj: Cell Reports; May 2022, Vol. 39 Issue: 9
Abstrakt: Lipid A, the membrane-anchored portion of lipopolysaccharide (LPS), is an essential component of the outer membrane (OM) of nearly all Gram-negative bacteria. Here we identify regulatory and structural factors that together render lipid A nonessential in Caulobacter crescentus. Mutations in the ferric uptake regulator furallow Caulobacterto survive in the absence of either LpxC, which catalyzes an early step of lipid A synthesis, or CtpA, a tyrosine phosphatase homolog we find is needed for wild-type lipid A structure and abundance. Alterations in Fur-regulated processes, rather than iron status per se, underlie the ability to survive when lipid A synthesis is blocked. Fitness of lipid A-deficient Caulobacterrequires an anionic sphingolipid, ceramide phosphoglycerate (CPG), which also mediates sensitivity to the antibiotic colistin. Our results demonstrate that, in an altered regulatory landscape, anionic sphingolipids can support the integrity of a lipid A-deficient OM.
Databáze: Supplemental Index