RNA molecules are not just messengers acting between DNA and proteins but rather required factors that play an active role in the expression of genes encoded in our genome. An RNA processing step called splicing can dramatically increase the diversity of proteins in human cells and tissues. RNA splicing is catalyzed by a large macromolecular complex, the spliceosome, which is formed from several RNA-protein complexes called snRNPs. In our group we are interested in spliceosome assembly, the organization of RNA splicing in the cell nucleus and regulation of alternative splicing. We also aim to determine how mutations in splicing factors can cause retinitis pigmentosa, a human genetic disease characterized by photoreceptor cell degeneration.

Using advanced microscopy techniques (e.g. live cell imaging, FRET, FCS) we explore where and when the spliceosome assembles in the cell nucleus. Experimental data are then used for modelling spliceosome assembly in the 3D space of the nuclear landscape. We identified the conserved nuclear compartment, the Cajal body, as the site of snRNP assembly and recycling, and proposed a model stating that the presence of Cajal bodies increases the efficiency of snRNP formation.