Collaboration between Plant Sciences and two research groups in Argentina leads to Nature paper: Linking alternative splicing and the circadian clock in Arabidopsis and Drosophila
A paper on alternative splicing and circadian rhythms in the model plant (Arabidopsis thaliana) and fruit fly (Drosophila melanogaster) was published in Nature on 4 November 2010 (Nature 468, 112-116).
The paper is the result of a collaboration between John Brown (Head of the Division of Plant Sciences CLS), Craig Simpson (SCRI) and the lead groups of Marcelo Yanovsky (IFEVA, Facultad de Agronomía, UBA-CONICET and the Fundación Instituto Leloir, IIBBA-CONICET) and Alberto Kornblihtt (IFIBYNE, FCEyN, UBA-CONICET) both from Buenos Aires, Argentina.
The research utilized the high resolution alternative splicing RT-PCR system for Arabidopsis developed by John Brown and Craig Simpson in Dundee with funding from EURASNET (the European Alternative Splicing Network of Excellence). EURASNET also supported the visit to Dundee of Ezequiel “Petry” Petrillo (PhD student and co-first author).
Alternative splicing is an important mechanism in the control of gene expression in plants and animals. Circadian rhythms control diverse aspects of plant growth and development and allow organisms to anticipate daily changes in environmental conditions and optimize timing of biological processes in the day-night cycle. The paper suggests a molecular mechanism by which the circadian clock and alternative splicing are linked.
PRMT5 (a methyl transferase) is very important in the control of alternative splicing of many genes in both plants and flies. PRMT5 can methylate histones and proteins of the spliceosome (the complex which carries out splicing). In Arabidopsis, the circadian clock controls PRMT5 expression and thereby alternative splicing of downstream genes. In addition, PRMT5 feeds back to the clock by controlling alternative splicing of at least one of the core clock genes, PRR9.
In Drosophila melanogaster, circadian rhythms in locomotor activity are disrupted in dart5-1, a mutant of the Drosophila PRMT5homologue. The changes in circadian rhythms are associated with altered splicing of the Drosophila core-clock gene period and several clock-associated genes.
In summary, PRMT5 has a key role in the interactions between the circadian clock and the regulation of alternative splicing and constitutes a common mechanism that helps organisms to synchronize physiological processes with daily changes in environmental conditions. The role of alternative splicing in modulating clock functions is a rapidly growing area with many more discoveries on the horizon.