RNA splicing, spliceosome formation, alternative splicing, Retinitis pigmentosa, nuclear structure
Our DNA encodes information for synthesis of all our proteins. However, this information in DNA is fragmented and genes contain long, seemingly “useless” sequences that need to be removed in a process called RNA splicing. Unused RNA sequences are removed by a large, sophisticated and dynamic molecular machine called the spliceosome, which is the most complex particle in our cells consisting of several non-coding RNAs and dozens of auxiliary proteins. Our long-term goal is to determine how does the spliceosome assemble at the right time and place inside the cell. We investigate, how nuclear architecture contributes to correct formation of the spliceosome and study molecular principles of a surveillance mechanism that distinguishes properly assembled splicing particles from defective ones. Finally, we aim to determine why mutations in several spliceosomal components cause Retinitis pigmentosa, a human genetic disease characterized by photoreceptor cell degeneration.
- Formation of spliceosomal complexes in vivo.
Using advanced microscopy techniques (e.g. live cell imaging, FRET, FRAP and FCS) we explore where and when the spliceosome components assemble in the cell nucleus. We identified a conserved nuclear compartment, the Cajal body, as the site of assembly and recycling of spliceosomal particles. Recently, we provided evidence that the Cajal body acts as a quality controller that surveillances formation of spliceosomal components and sequesters defective particles. Currently, we are investigating molecular mechanism that discriminate between correctly and incorrectly assembled particles. Because RNA splicing and spliceosome formation is intimately associated with Cajal body formation, we also investigate molecular principles that governs assembly of this nuclear compartment.
- Spliceosome and retina degeneration.
The autosomal dominant disorder Retinitis pigmentosa (RP) is characterized by progressive loss of peripheral and night vision, which eventually leads to total blindness. RP is caused by molecular defects in many different proteins including those found in the spliceosome. Why mutations of ubiquitous spliceosomal components specifically affect retina cells however remains elusive. In our research, we use methods developed to study spliceosome and RNA splicing (see above) and apply them to animal RP models and human retinal organoids to identify the deleterious effects of RP mutations in the splicing complex on human photoreceptors.
David Stanek – Seminar at the International Centre for Genetic Engineering and Biotechnology, Trieste, Italy, October, 2016.
Last change: May 19, 2020