Circadian control of messenger RNA stability. association with a sequence-specific messenger RNA decay pathway

• Published in: Plant physiology (Bethesda) 2005-08, Vol.138 (4), p.2374-2385
• Main Authors: Lidder, P, Gutierrez, R.A, Salome, P.A, McClung, C.R, Green, P.J
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Arabidopsis - metabolism; Arabidopsis Proteins - biosynthesis; Arabidopsis thaliana; Biological and medical sciences; circadian clock; Circadian Rhythm; Classical and quantitative genetics. Population genetics. Molecular genetics; cold circadian rhythm and RNA-binding like gene; Cotyledons; Drosophila; Fundamental and applied biological sciences. Psychology; Gene expression regulation; Generalities. Genetics. Plant material; Genes; Genetics and breeding of economic plants; Genetics, Genomics, and Molecular Evolution; Half lives; Light; Messenger RNA; Molecular genetics; P values; plant biochemistry; plant genetics; plant proteins; Plant Proteins - biosynthesis; RNA; RNA stability; RNA, Messenger - biosynthesis; RNA, Messenger - chemistry; RNA, Messenger - metabolism; senescence associated gene; transcription (genetics)
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.105.060368

Transcriptional and posttranscriptional regulation are well-established mechanisms for circadian gene expression. Among the latter, differential messenger RNA (mRNA) stability has been hypothesized to control gene expression in response to the clock. However, direct proof that the rate of mRNA turnover can be regulated by the clock is lacking. Previous microarray expression data for unstable mRNAs in Arabidopsis (Arabidopsis thaliana) revealed that mRNA instability is associated with a group of genes controlled by the circadian clock. Here, we show that CCR-LIKE (CCL) and SENESCENCE ASSOCIATED GENE 1 transcripts are differentially regulated at the level of mRNA stability at different times of day. In addition, the changes in CCL mRNA stability continue under free-running conditions, indicating that it is controlled by the Arabidopsis circadian clock. Furthermore, we show that these mRNAs are targets of the mRNA degradation pathway mediated by the downstream (DST) instability determinant. Disruption of the DST-mediated decay pathway in the dst1 mutant leads to aberrant circadian mRNA oscillations that correlate with alterations of the half-life of CCL mRNA relative to parental plants in the morning and afternoon. That this is due to an effect on the circadian control is evidenced by mRNA decay experiments carried out in continuous light. Finally, we show that the defects exhibited by dst mutants are reflected by an impact on circadian regulation at the whole plant level. Together, these results demonstrate that regulation of mRNA stability is important for clock-controlled expression of specific genes in Arabidopsis. Moreover, these data uncover a connection between circadian rhythms and a sequence-specific mRNA decay pathway.