Bacterial cells are intricately organized, despite the lack of membrane-bounded organelles. The extremely crowded cytoplasm promotes macromolecular self-assembly and formation of distinct subcellular structures, which perform specialized functions. For example, the cell poles act as hubs for signal transduction complexes, thus providing a platform for the coordination of optimal cellular responses to environmental cues. Distribution of macromolecules is mostly mediated via specialized transport machineries, including the MreB cytoskeleton. Recent evidence shows that RNAs also specifically localize within bacterial cells, raising the possibility that gene expression is spatially organized. This review describes the current understanding of where things are in bacterial cells and discuss emerging questions that need to be addressed in the future.
- Bacterial cells are intricately organized, with many proteins and RNAs being specifically localized.
- The poles of rod-shaped bacterial cells are emerging as subcellular regions of importance for sensing and signaling.
- The MreB cytoskeletal system plays an important role in cellular trafficking of macromolecules.
- Subcellular domains in bacterial cells are connected through a complex network of interactions.