Galej Group

Structure and function of RNA-protein complexes

The Galej group uses an integrated structural biology approach combined with biochemistry and biophysics to investigate large RNA-protein complexes involved in gene expression.


Previous and current research

In eukaryotes, genetic information in protein-coding genes is dispersed in the form of short fragments (exons), which are punctuated with non-coding segments known as introns. Introns are removed from precursors of messenger RNAs (pre-mRNA) in a reaction catalysed by a multi-megadalton RNA–protein complex – the spliceosome. More than 100 proteins and five small nuclear RNAs (snRNAs) are involved in orchestrating this process. Among them, five small nuclear ribonucleoprotein particles (U1, U2, U4/U6, and U5 snRNPs) are the major building blocks of the splicing machinery. Recent technological advances in cryo-electron microscopy (cryo-EM) have allowed determination of high-resolution structures for nearly all yeast spliceosome assembly intermediates, providing unprecedented mechanistic insights into spliceosome assembly, activation, and catalysis.

Our group investigates three major problems related to the pre-mRNA splicing:

  1. U12-dependent splicing in mammalian cells.
  2. Biogenesis of snRNPs, the building blocks of the spliceosome.
  3. snRNA processing in metazoans by the Integrator complex.

Our vision and approach

Mechanistic understanding of biological processes requires structural information on multiple scales. Research in my group employs cutting-edge structural biology technologies in investigating macromolecular complexes involved in the expression of the genetic information. By combining single particle electron cryo-microscopy (cryo-EM) with cell biology and biochemical and biophysical approaches, we aim to understand the inner workings of the large, multi-subunit RNA-protein complexes, involved in pre-mRNA splicing, snRNPs biogenesis and the 3’-end processing. These fundamentally important cellular processes are relevant to human health and their mechanistic understanding is of a critical importance for both, basic and applied research.

We employ modern genome engineering technologies and biochemical reconstitution methods with state-of-the-art electron microscopy approaches in order to visualise dynamic and flexible protein complexes. With a strong focus on biological problems, we aim to push the resolution limits and investigate ever more complex and dynamic machineries. In the fast-changing field of structural biology, we remain flexible and endorse new methodological developments in pursuing our biology- oriented research questions. As such, for our future goals we aspire to take advantage the newly emerging in situ structural biology methodologies and deep learning approaches to facilitate our progress.

Future projects

  • Mechanism of the branch site recognition by the U2 snRNP
  • Structural and functional characterisation of the minor spliceosome
  • DExD/H helicases and their involvement in pre-mRNA splicing
  • cryo-ET studies of the splicing machinery