Regulatory RNAs in photosynthetic cyanobacteria.
Regulatory RNAs play versatile roles in bacteria in the coordination of gene expression during various physiological processes, especially during stress adaptation. Photosynthetic bacteria use sunlight as their major energy source. Therefore, they are particularly vulnerable to the damaging effects of excess light or UV irradiation. In addition, like all bacteria, photosynthetic bacteria must adapt to limiting nutrient concentrations and abiotic and biotic stress factors. Transcriptome analyses have identified hundreds of potential regulatory small RNAs (sRNAs) in model cyanobacteria such as Synechocystis sp. PCC 6803 or Anabaena sp. PCC 7120, and in environmentally relevant genera such as Trichodesmium, Synechococcus and Prochlorococcus. Some sRNAs have been shown to actually contain μORFs and encode short proteins. Examples include the 40-amino-acid product of the sml0013 gene, which encodes the NdhP subunit of the NDH1 complex. In contrast, the functional characterization of the non-coding sRNA PsrR1 revealed that the 131 nt long sRNA controls photosynthetic functions by targeting multiple mRNAs, providing a paradigm for sRNA functions in photosynthetic bacteria. We suggest that actuatons comprise a new class of genetic elements in which an sRNA gene is inserted upstream of a coding region to modify or enable transcription of that region.
Faculty of Biology, Institute of Biology III, University of Freiburg, D-79104 Freiburg, Germany.
Matthias
M
Kopf
Faculty of Biology, Institute of Biology III, University of Freiburg, D-79104 Freiburg, Germany wolfgang.hess@biologie.uni-freiburg.de.
Wolfgang R
WR
Hess
D001426:Bacterial Proteins / Q000235:genetics; D000458:Cyanobacteria / Q000235:genetics / Q000502:physiology*; D004777:Environment; D015964:Gene Expression Regulation, Bacterial; D010788:Photosynthesis; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D038621:Regulatory Sequences, Ribonucleic Acid / Q000235:genetics; D013312:Stress, Physiological / Q000235:genetics; D059467:Transcriptome
D001426:Bacterial Proteins; D012329:RNA, Bacterial; D038621:Regulatory Sequences, Ribonucleic Acid
comparative transcriptome analysis; cyanobacteria; differential RNA-seq; gene expression regulation; photosynthesis; sRNAs