SgrS RNA

SgrS (sugar transport-related sRNA, previously named ryaA)^[1] is a 227 nucleotide small RNA that is activated by SgrR in Escherichia coli during glucose-phosphate stress. The nature of glucose-phosphate stress is not fully understood, but is correlated with intracellular accumulation of glucose-6-phosphate.^[2] SgrS helps cells recover from glucose-phosphate stress by base pairing with ptsG mRNA (encoding the glucose transporter) and causing its degradation in an RNase E dependent manner.^[3][4] Base pairing between SgrS and ptsG mRNA also requires Hfq, an RNA chaperone frequently required by small RNAs that affect their targets through base pairing.^[5] The inability of cells expressing sgrS to create new glucose transporters leads to less glucose uptake and reduced levels of glucose-6-phosphate. SgrS is an unusual small RNA in that it also encodes a 43 amino acid functional polypeptide, SgrT, which helps cells recover from glucose-phosphate stress by preventing glucose uptake. The activity of SgrT does not affect the levels of ptsG mRNA of PtsG protein.^[2] It has been proposed that SgrT exerts its effects through regulation of the glucose transporter, PtsG.^[6][7]

SgrS RNA
Predicted secondary structure and sequence conservation of SgrS
Identifiers
Symbol	SgrS
Rfam	RF00534
Other data
RNA type	Gene; antisense
Domain(s)	Bacteria
GO	GO:0032057 GO:0043488 GO:0030371
SO	SO:0000655
PDB structures	PDBe

SgrS was originally discovered in E. coli but homologues have since been identified in other Gammaproteobacteria such as Salmonella enterica and members of the genus Citrobacter.^[8] A comparative genomics based target prediction approach that employs these homologs, has been developed and was used to predict the SgrS target, ptsI (b2416), which was subsequently verified experimentally.^[9]

References

1. Vanderpool CK, Gottesman S (November 2004). "Involvement of a novel transcriptional activator and small RNA in post-transcriptional regulation of the glucose phosphoenolpyruvate phosphotransferase system". Molecular Microbiology. 54 (4): 1076–89. doi:10.1111/j.1365-2958.2004.04348.x. PMID 15522088. S2CID 24804508.
2. Wadler CS, Vanderpool CK (December 2007). "A dual function for a bacterial small RNA: SgrS performs base pairing-dependent regulation and encodes a functional polypeptide". Proceedings of the National Academy of Sciences of the United States of America. 104 (51): 20454–9. doi:10.1073/pnas.0708102104. PMC 2154452. PMID 18042713.
3. Vanderpool CK, Gottesman S (March 2007). "The novel transcription factor SgrR coordinates the response to glucose-phosphate stress". Journal of Bacteriology. 189 (6): 2238–48. doi:10.1128/JB.01689-06. PMC 1899371. PMID 17209026.
4. Rice JB, Vanderpool CK (May 2011). "The small RNA SgrS controls sugar-phosphate accumulation by regulating multiple PTS genes". Nucleic Acids Research. 39 (9): 3806–19. doi:10.1093/nar/gkq1219. PMC 3089445. PMID 21245045.
5. Kawamoto H, Koide Y, Morita T, Aiba H (August 2006). "Base-pairing requirement for RNA silencing by a bacterial small RNA and acceleration of duplex formation by Hfq". Molecular Microbiology. 61 (4): 1013–22. doi:10.1111/j.1365-2958.2006.05288.x. PMID 16859494. S2CID 35533720.
6. Maki K, Morita T, Otaka H, Aiba H (May 2010). "A minimal base-pairing region of a bacterial small RNA SgrS required for translational repression of ptsG mRNA". Molecular Microbiology. 76 (3): 782–92. doi:10.1111/j.1365-2958.2010.07141.x. PMID 20345651. S2CID 39687800.
7. Kawamoto H, Morita T, Shimizu A, Inada T, Aiba H (February 2005). "Implication of membrane localization of target mRNA in the action of a small RNA: mechanism of post-transcriptional regulation of glucose transporter in Escherichia coli". Genes & Development. 19 (3): 328–38. doi:10.1101/gad.1270605. PMC 546511. PMID 15650111.
8. Horler RS, Vanderpool CK (September 2009). "Homologs of the small RNA SgrS are broadly distributed in enteric bacteria but have diverged in size and sequence". Nucleic Acids Research. 37 (16): 5465–76. doi:10.1093/nar/gkp501. PMC 2760817. PMID 19531735.
9. Wright PR, Richter AS, Papenfort K, Mann M, Vogel J, Hess WR, Backofen R, Georg J (September 2013). "Comparative genomics boosts target prediction for bacterial small RNAs". Proceedings of the National Academy of Sciences of the United States of America. 110 (37): E3487-96. Bibcode:2013PNAS..110E3487W. doi:10.1073/pnas.1303248110. PMC 3773804. PMID 23980183.

Further reading

• Vanderpool CK (April 2007). "Physiological consequences of small RNA-mediated regulation of glucose-phosphate stress". Current Opinion in Microbiology. 10 (2): 146–51. doi:10.1016/j.mib.2007.03.011. PMID 17383224.
• Aiba H (April 2007). "Mechanism of RNA silencing by Hfq-binding small RNAs". Current Opinion in Microbiology. 10 (2): 134–9. doi:10.1016/j.mib.2007.03.010. PMID 17383928.
• Sun Y, Vanderpool CK (November 2013). "Physiological consequences of multiple-target regulation by the small RNA SgrS in Escherichia coli". Journal of Bacteriology. 195 (21): 4804–15. doi:10.1128/JB.00722-13. PMC 3807494. PMID 23873911.
• Bobrovskyy M, Vanderpool CK (2014). "The small RNA SgrS: roles in metabolism and pathogenesis of enteric bacteria". Frontiers in Cellular and Infection Microbiology. 4: 61. doi:10.3389/fcimb.2014.00061. PMC 4021124. PMID 24847473.
• Papenfort K, Sun Y, Miyakoshi M, Vanderpool CK, Vogel J (April 2013). "Small RNA-mediated activation of sugar phosphatase mRNA regulates glucose homeostasis". Cell. 153 (2): 426–37. doi:10.1016/j.cell.2013.03.003. PMC 4151517. PMID 23582330.

External links

• Page for SgrS RNA at Rfam
• sRNAmap page for SgrS RNA
• Vanderpool Lab
• Aiba Lab