During the early steps of snRNP biogenesis, the survival motor neuron (SMN) complex acts together with the methylosome, an entity formed by the pICln protein, WD45, and the PRMT5 methyltransferase. To expand our understanding of the functional relationship between pICln and SMN in vivo, we performed a genetic analysis of an uncharacterized Schizosaccharomyces pombe pICln homolog. Although not essential, the S. pombe ICln (SpICln) protein is important for optimal yeast cell growth. The human ICLN gene complements the Deltaicln slow-growth phenotype, demonstrating that the identified SpICln sequence is the bona fide human homolog. Consistent with the role of human pICln inferred from in vitro experiments, we found that the SpICln protein is required for optimal production of the spliceosomal snRNPs and for efficient splicing in vivo. Genetic interaction approaches further demonstrate that modulation of ICln activity is unable to compensate for growth defects of SMN-deficient cells. Using a genome-wide approach and reverse transcription (RT)-PCR validation tests, we also show that splicing is differentially altered in Deltaicln cells. Our data are consistent with the notion that splice site selection and spliceosome kinetics are highly dependent on the concentration of core spliceosomal components.
Characterization and in vivo functional analysis of the Schizosaccharomyces pombe ICLN gene
Barbarossa, A.; Antoine, E.; Neel, H.; Gostan, T.; Soret, J.; Bordonne, R.
Mol Cell Biol
2014-02 / vol 34 / pages 595-605
10.1128/MCB.01407-13 MCB.01407-13 [pii]
1098-5549 (Electronic) 0270-7306 (Linking)
IGMM team(s) involved in this publication
Assembly and Traffic of Ribonucleoproteins
Complex Biological Data Analysis Service
Humans; Cytoplasm/genetics/metabolism; Ion Channels/*genetics/metabolism; Methyltransferases/genetics/metabolism; Motor Neurons/*metabolism; Protein Binding/genetics; Protein Methyltransferases/genetics/metabolism; RNA Splicing/*genetics; Schizosaccharomyces/*genetics/metabolism; Spliceosomes/*genetics/metabolism