Abstract
The intricate structure of prokaryotic and eukaryotic cells depends on the ability to target proteins to specific cellular locations. In most cases, we have a poor understanding of the underlying mechanisms. A typical example is the assembly of bacterial chemoreceptors at cell poles. Here we show that the classical chemoreceptor TlpA of Bacillus subtilis does not localize according to the consensus stochastic nucleation mechanism but accumulates at strongly curved membrane areas generated during cell division. This preference was confirmed by accumulation at non-septal curved membranes. Localization appears to be an intrinsic property of the protein complex and does not rely on chemoreceptor clustering, as was previously shown for Escherichia coli. By constructing specific amino-acid substitutions, we demonstrate that the preference for strongly curved membranes arises from the curved shape of chemoreceptor trimer of dimers. These findings demonstrate that the intrinsic shape of transmembrane proteins can determine their cellular localization.
Highlights
The intricate structure of prokaryotic and eukaryotic cells depends on the ability to target proteins to specific cellular locations
The in vivo data support the stochastic nucleation model[12,13,14]. To examine whether this mechanism is active in other rod-shaped bacteria such as the Gram-positive model organism Bacillus subtilis, we followed the localization of a typical chemoreceptor protein in this organism
In an alternative model postulated by Endres[16], the curved shape of large chemoreceptor clusters provides the force that drives the chemoreceptors to the cell poles
Summary
The intricate structure of prokaryotic and eukaryotic cells depends on the ability to target proteins to specific cellular locations. A classic example is the polar localization pattern of the chemotactic sensory complexes[6,7] Bacteria sense their surrounding by transmembrane or cytoplasmic chemoreceptor proteins that form dimers, which assemble into trimers. The assembly of individual sensory proteins into large clusters provides high sensitivity, and allows the cell to integrate various environmental signals into a unified output[8,9] These intricate signal transduction complexes regulate flagellar rotation, thereby controlling the swimming direction of bacteria[10,11]. In their seminal paper 420 years ago, Maddock and Shapiro showed that bacterial chemoreceptor clusters are localized at cell poles in Escherichia coli[7]. The similarities and differences with existing localization models are discussed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
