Abstract
Antisense RNAs that originate from the complementary strand of protein coding genes are involved in the regulation of gene expression in all domains of life. In bacteria, some of these antisense RNAs are transcriptional noise whiles others play a vital role to adapt the cell to changing environmental conditions. By deep sequencing analysis of transcriptome of Salmonella enterica serovar Typhi, a partial RNA sequence encoded in-cis to the dnaA gene was revealed. Northern blot and RACE analysis confirmed the transcription of this antisense RNA which was expressed mostly in the stationary phase of the bacterial growth and also under iron limitation and osmotic stress. Pulse expression analysis showed that overexpression of the antisense RNA resulted in a significant increase in the mRNA levels of dnaA, which will ultimately enhance their translation. Our findings have revealed that antisense RNA of dnaA is indeed transcribed not merely as a by-product of the cell's transcription machinery but plays a vital role as far as stability of dnaA mRNA is concerned.
Highlights
Many non-coding RNAs in bacteria have been identified in recent times to adapt the bacteria to changing environmental conditions as well as influencing their virulence
Trans-encoded RNAs are located in another chromosomal location, and are only partially complementary to their target RNA(s), whereas the less focused on cis-encoded antisense RNAs are located in the same DNA region and are, fully complementary to their targets over a large nucleotide stretch [2]
Chromosomal antisense transcription has been shown to be widespread in bacterial genomes [27,33,34], it has attracted less attention and so the conditions that govern the synthesis of these antisense RNAs, as well as their physiological role and mechanism of action remain largely unknown
Summary
Many non-coding RNAs (ncRNAs) in bacteria have been identified in recent times to adapt the bacteria to changing environmental conditions as well as influencing their virulence. Trans-encoded RNAs are located in another chromosomal location, and are only partially complementary to their target RNA(s), whereas the less focused on cis-encoded antisense RNAs (asRNAs) are located in the same DNA region and are, fully complementary to their targets over a large nucleotide stretch [2]. The chromosomally encoded asRNAs differ in size as well as region of overlap between them and their target mRNAs. Many are substantially long, ranging from 700 to 3,500 nt, some are only 100 nt in size. The known regulatory mechanisms employed by cisencoded asRNAs include transcription attenuation, translation inhibition, inhibition of primer maturation, promotion or inhibition of mRNA degradation and prevention of RNA pseudoknot formation [4,5]. AsRNAs are involved in a number of cellular processes in bacteria, including acid resistance [6], iron homeostasis [7], quorum sensing [8], Mg+2/Ca+2 transport and virulence [9,10,11], ABC transport systems [12], global repression of OMP synthesis [13,14] and control of expression of global transcription factors [15,16]
Sign-in/Register to view highlights & summary 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.
