HOMEPRODUCTSCOMPANYCONTACTFAQResearchDictionaryPharmaSign Up FREE or Login

The significance of translation regulation in the stress response.

AbstractBACKGROUND:
The stress response in bacteria involves the multistage control of gene expression but is not entirely understood. To identify the translational response of bacteria in stress conditions and assess its contribution to the regulation of gene expression, the translational states of all mRNAs were compared under optimal growth condition and during nutrient (isoleucine) starvation.
RESULTS:
A genome-scale study of the translational response to nutritional limitation was performed in the model bacterium Lactococcus lactis. Two measures were used to assess the translational status of each individual mRNA: the fraction engaged in translation (ribosome occupancy) and ribosome density (number of ribosomes per 100 nucleotides). Under isoleucine starvation, half of the mRNAs considered were translationally down-regulated mainly due to decreased ribosome density. This pattern concerned genes involved in growth-related functions such as translation, transcription, and the metabolism of fatty acids, phospholipids and bases, contributing to the slowdown of growth. Only 4% of the mRNAs were translationally up-regulated, mostly related to prophagic expression in response to stress. The remaining genes exhibited antagonistic regulations of the two markers of translation. Ribosome occupancy increased significantly for all the genes involved in the biosynthesis of isoleucine, although their ribosome density had decreased. The results revealed complex translational regulation of this pathway, essential to cope with isoleucine starvation.To elucidate the regulation of global gene expression more generally, translational regulation was compared to transcriptional regulation under isoleucine starvation and to other post-transcriptional regulations related to mRNA degradation and mRNA dilution by growth. Translational regulation appeared to accentuate the effects of transcriptional changes for down-regulated growth-related functions under isoleucine starvation although mRNA stabilization and lower dilution by growth counterbalanced this effect.
CONCLUSIONS:
We show that the contribution of translational regulation to the control of gene expression is significant in the stress response. Post-transcriptional regulation is complex and not systematically co-directional with transcription regulation. Post-transcriptional regulation is important to the understanding of gene expression control.
AuthorsFlora Picard, Pascal Loubière, Laurence Girbal, Muriel Cocaign-Bousquet
JournalBMC genomics (BMC Genomics) Vol. 14 Pg. 588 (Aug 28 2013) ISSN: 1471-2164 [Electronic] England
PMID23985063 (Publication Type: Journal Article)
Chemical References
  • Bacterial Proteins
  • RNA, Messenger
  • Isoleucine
Topics
  • Adaptation, Physiological (genetics)
  • Bacterial Proteins (genetics, metabolism)
  • Cluster Analysis
  • Gene Expression Regulation, Bacterial
  • Isoleucine (deficiency)
  • Lactococcus lactis (genetics, metabolism)
  • Polyribosomes (metabolism)
  • Protein Biosynthesis
  • RNA, Messenger (genetics, metabolism)
  • Stress, Physiological (genetics)
  • Transcriptome

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!


Choose Username:
Email:
Password:
Verify Password:
Enter Code Shown: