Membrane fluidity controls peptidoglycan synthesis and MreB movement

Abstract The bacterial plasma membrane is an important cellular compartment. In recent years it has become obvious that protein complexes and lipids are not uniformly distributed within membranes. Current hypotheses suggest that flotillin proteins are required for the formation of complexes of membrane proteins including cell-wall synthetic proteins. We show here that bacterial flotillins are important factors for membrane fluidity homeostasis. Loss of flotillins leads to changes in membrane fluidity that in turn lead to alterations in MreB dynamics and, as a consequence, in peptidoglycan synthesis. Our data support a model in which flotillins are required for growth-rate dependent control of membrane fluidity rather than for the formation of protein complexes via direct protein-protein interactions.