All in the Family: Kin Contact Leads to Outer Membrane Exchange

Hartzell, Trish

doi:10.1128/jb.01617-14

Cited by 1 publication

(1 citation statement)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, on the basis of a priori evidence and our screen, the TraAB proteins may be sufficient to explain OM fusion in myxobacteria. Moreover, as no mutants were found to be defective in the production of OM tubes, which are long narrow outer membrane-enclosed cellular appendages (35), these or other overt cellular structures appear to not be required for OME, as previously suggested (35,36).…”

Section: Discussionmentioning

confidence: 68%

A Genetic Screen in Myxococcus xanthus Identifies Mutants That Uncouple Outer Membrane Exchange from a Downstream Cellular Response

Dey

Wall

2014

J Bacteriol

View full text Add to dashboard Cite

Upon physical contact with sibling cells, myxobacteria transiently fuse their outer membranes (OMs) and exchange OM proteins and lipids. From previous work, TraA and TraB were identified to be essential factors for OM exchange (OME) in donor and recipient cells. To define the genetic complexity of OME, we carried out a comprehensive forward genetic screen. The screen was based on the observation that Myxococcus xanthus nonmotile cells, by a Tra-dependent mechanism, block swarm expansion of motile cells when mixed. Thus, mutants defective in OME or a downstream responsive pathway were readily identified as escape flares from mixed inocula seeded on agar. This screen was surprisingly powerful, as we found >50 mutants defective in OME. Importantly, all of the mutations mapped to the traAB operon, suggesting that there may be few, if any, proteins besides TraA and TraB directly required for OME. We also found a second and phenotypically different class of mutants that exhibited wildtype OME but were defective in a responsive pathway. This pathway is postulated to control inner membrane homeostasis by covalently attaching amino acids to phospholipids. The identified proteins are homologous to the Staphylococcus aureus MprF protein, which is involved in membrane adaptation and antibiotic resistance. Interestingly, we also found that a small number of nonmotile cells were sufficient to block the swarming behavior of a large gliding-proficient population. This result suggests that an OME-derived signal could be amplified from a few nonmotile producers to act on many responder cells.

show abstract

Section: Discussionmentioning

confidence: 68%