Role for LSM genes in the regulation of circadian rhythms.

SOLEDAD PEREZ SANTANGELO; ESTEFANIA MANCINI; LAUREN J. FRANCEY; RUBEN GUSTAVO SCHLAEN; ARIEL CHERNOMORETZ; MARCELO YANOVSKY

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

NATL ACAD SCIENCES

Lugar: Washington DC, USA; Año: 2014 vol. 111

0027-8424

Growing evidence suggests that core spliceosomal componentsdifferentially affect RNA processing of specific genes; however,whether changes in the levels or activities of these factors controlspecific signaling pathways is largely unknown. Here we showthat some SM-like (LSM) genes, which encode core componentsof the spliceosomal U6 small nuclear ribonucleoprotein complex,regulate circadian rhythms in plants and mammals. We foundthat the circadian clock regulates the expression of LSM5 inArabidopsis plants and several LSM genes in mouse suprachias-matic nucleus. Further, mutations in LSM5 or LSM4 in Arabidop-sis, or down-regulation of LSM3, LSM5, or LSM7 expression inhuman cells, lengthens the circadian period. Although we identifiedchanges in the expression and alternative splicing of some coreclock genes in Arabidopsis lsm5 mutants, the precise molecularmechanism causing period lengthening remains to be identified.Genome-wide expression analysis of either a weak lsm5 or astrong lsm4 mutant allele in Arabidopsis revealed larger effectson alternative splicing than on constitutive splicing. Remarkably,large splicing defects were not observed in most of the intronsevaluated using RNA-seq in the strong lsm4 mutant allele usedin this study. These findings support the idea that some LSM genesplay both regulatory and constitutive roles in RNA processing,contributing to the fine-tuning of specific signaling pathways.