Orchestration of thiamin biosynthesis and central metabolism by combined action of the thiamin pyrophosphate riboswitch and the circadian clock in Arabidopsis

Samuel E. Bocobza, Sergey Malitsky, Wagner L. Araújo, Adriano Nunes-Nesi, Sagit Meir, Michal Shapira, Alisdair R. Fernie, Asaph Aharoni

Research output: Contribution to journalArticlepeer-review

67 Scopus citations

Abstract

Riboswitches are natural RNA elements that posttranscriptionally regulate gene expression by binding small molecules and thereby autonomously control intracellular levels of these metabolites. Although riboswitch-based mechanisms have been examined extensively, the integration of their activity with global physiology and metabolism has been largely overlooked. Here, we explored the regulation of thiamin biosynthesis and the consequences of thiamin pyrophosphate riboswitch deficiency on metabolism in Arabidopsis thaliana. Our results show that thiamin biosynthesis is largely regulated by the circadian clock via the activity of the THIAMIN C SYNTHASE (THIC) promoter, while the riboswitch located at the 39 untranslated region of this gene controls overall thiamin biosynthesis. Surprisingly, the results also indicate that the rate of thiamin biosynthesis directs the activity of thiamin-requiring enzymes and consecutively determines the rate of carbohydrate oxidation via the tricarboxylic acid cycle and pentose-phosphate pathway. Our model suggests that in Arabidopsis, the THIC promoter and the thiamin-pyrophosphate riboswitch act simultaneously to tightly regulate thiamin biosynthesis in a circadian manner and consequently sense and control vital points of core cellular metabolism.

Original languageEnglish
Pages (from-to)288-307
Number of pages20
JournalPlant Cell
Volume25
Issue number1
DOIs
StatePublished - 1 Jan 2013

ASJC Scopus subject areas

  • Plant Science
  • Cell Biology

Fingerprint

Dive into the research topics of 'Orchestration of thiamin biosynthesis and central metabolism by combined action of the thiamin pyrophosphate riboswitch and the circadian clock in Arabidopsis'. Together they form a unique fingerprint.

Cite this