The snRNP assembly factor pICln modulates low temperature effects on alternative splicing and growth in Arabidopsis

JULIETA L, MATEOS

Bielefeld

Congreso; Emerging new techniques to unravel transcriptional and post-transcriptional regulation in plants on a global scale; 2021

The snRNP assembly factor pICln modulates low temperature effects on alternative splicing and growth in Arabidopsis Julieta L. Mateos(1), Sabrina E Sanchez (2), Martina Legris(3), David Esteve(4), Jeannette Torchio(2), Ezequiel Petrillo(1), Danelle Seymour(5), Detlef Weigel(5), David Alabadi(4), and Marcelo J. Yanovsky(2)(1) Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Argentina (2) Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina(3) Centre for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland.(4) Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas, Universidad Politécnica de Valencia, 46022 Valencia, Spain(5) Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tuebingen, 72076, Germany. Efficient pre-mRNA splicing depends on proper spliceosome assembly, which in animals requires the activity of the SMN and PRMT5 protein complexes in vivo. pICln is part of the PRMT5-methylosome complex in Arabidopsis, but its impact on pre-mRNA splicing in plants is uncertain. Here we conducted a detailed characterization of Arabidopsis pICln mutants and found significant alterations in pre-mRNA splicing, photomorphogenic and photoperiodic responses. These alterations were complemented by the human PICLN orthologue, and only partially overlapped with those previously observed in prmt5 mutants. Indeed, pICln interacted with Sm and LSm proteins, but PRMT5-dependent symmetric arginine dimethylation of SmB or LSm4 proteins was not affected in pICln mutants. In mammals, besides being a methylosome component, pICln acts with the SMN component GEMIN2 modulating late steps of UsnRNP assembly. Interestingly, many AS events regulated by PICLN were also controlled by GEMIN2 and by the core SmE protein PCP. Furthermore, similarly to GEMIN2 and SME/PCP, PICLN expression was regulated by low temperature and the pICln mutant showed temperature dependent growth phenotypes. Taken together, these results firmly establish that spliceosome assembly factors play a key role modulating alternative pre-mRNA splicing and plant acclimation in response to environmental stress conditions.