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Leaderless mRNAs in the Spotlight: Ancient but Not Outdated!
- Source :
-
Microbiology spectrum [Microbiol Spectr] 2018 Jul; Vol. 6 (4). - Publication Year :
- 2018
-
Abstract
- Previously, leaderless mRNAs (lmRNAs) were perceived to make up only a minor fraction of the transcriptome in bacteria. However, advancements in RNA sequencing technology are uncovering vast numbers of lmRNAs, particularly in archaea, Actinobacteria , and extremophiles and thus underline their significance in cellular physiology and regulation. Due to the absence of conventional ribosome binding signals, lmRNA translation initiation is distinct from canonical mRNAs and can therefore be differentially regulated. The ribosome's inherent ability to bind a 5'-terminal AUG can stabilize and protect the lmRNA from degradation or allow ribosomal loading for downstream initiation events. As a result, lmRNAs remain translationally competent during a variety of physiological conditions, allowing them to contribute to multiple regulatory mechanisms. Furthermore, the abundance of lmRNAs can increase during adverse conditions through the upregulation of lmRNA transcription from alternative promoters or by the generation of lmRNAs from canonical mRNAs cleaved by an endonucleolytic toxin. In these ways, lmRNA translation can continue during stress and contribute to regulation, illustrating their importance in the cell. Due to their presence in all domains of life and their ability to be translated by heterologous hosts, lmRNAs appear further to represent ancestral transcripts that might allow us to study the evolution of the ribosome and the translational process.
- Subjects :
- 5' Untranslated Regions
Archaea genetics
Bacteria genetics
Base Sequence
Codon, Initiator
Gene Expression Regulation, Archaeal physiology
Gene Expression Regulation, Bacterial physiology
Ribosomal Proteins
Stress, Psychological
Transcriptome
Archaea metabolism
Bacteria metabolism
RNA, Bacterial physiology
RNA, Messenger physiology
Subjects
Details
- Language :
- English
- ISSN :
- 2165-0497
- Volume :
- 6
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Microbiology spectrum
- Publication Type :
- Academic Journal
- Accession number :
- 30006995
- Full Text :
- https://doi.org/10.1128/microbiolspec.RWR-0016-2017