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Published on: January 27, 2021
Subcellular localization of a bacterial regulatory RNA
Jay H Russell1, Kenneth C Keiler
1The Pennsylvania State University, Department of Biochemistry and Molecular Biology, 401 Althouse Lab, University Park, PA 16802, USA.
Summary
Bacteria spatially regulate RNA localization, with tmRNA forming helix-like structures in G1-phase cells. This localization sequesters tmRNA from degradation, potentially regulating its interaction with ribosomes during trans-translation.
Area of Science:
- Bacterial molecular biology
- RNA localization
- Cell cycle regulation
Background:
- Eukaryotes and bacteria utilize subcellular localization for protein regulation.
- Eukaryotes also employ RNA localization for functional control.
- The spatial regulation of bacterial RNAs remains largely unexplored.
Purpose of the Study:
- To investigate whether bacteria spatially regulate RNA localization.
- To determine the cellular localization patterns of tmRNA in Caulobacter crescentus.
- To elucidate the role of localization in tmRNA function and regulation.
Main Methods:
- Fluorescence in situ hybridization (FISH) to visualize tmRNA localization.
- Immunofluorescence assays to detect protein localization (SmpB and RNase R).
- Cell cycle analysis to correlate tmRNA localization with cell division stages.
Main Results:
- tmRNA exhibits cell-cycle-dependent localization in Caulobacter crescentus.
- In G1-phase cells, tmRNA forms regularly spaced foci in a helix-like pattern.
- SmpB colocalizes with tmRNA, while the degrading enzyme RNase R localizes separately.
- tmRNA is degraded after DNA replication initiation, with remaining molecules dispersing.
Conclusions:
- Bacterial RNA localization, exemplified by tmRNA, is a regulated process.
- tmRNA-SmpB complex localization may sequester tmRNA from RNase R, preventing degradation.
- Spatial organization of tmRNA-SmpB could modulate its interaction with ribosomes during trans-translation.
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