Nielsen Group

PI:
Henrik Nielsen, Professor MSO (Copenhagen) and Professor 2 (Tromsø)
Participating group members:
Postdocs Mikkel Dalsgaard-Christensen and Kasper Langebjerg Andersen, Research assistant Ulf Birkedal, Master students Nicolai Krogh and Theis Andersen.
Address etc.:
Department of Cellular and Molecular Medicine, Faculty of Health Science, University of Copenhagen, 3 Blegdamsvej, DK. email: hamra@sund.ku.dk

Profile of the group:

The main research topic of the lab is the GIR1 branching ribozyme that catalyze cleavage of RNA by a branching reaction (to produce a lariat cap). We have recently characterized a regulatory switching mechanism in GIR1 and are continuing our studies of the function of GIR1 in relation to the biology of twin-ribozyme introns (with Steinar Johansen, Tromsø). Structural work, including NMR and X-crystallography, is done in collaboration with Eric Westhof and Benoit Masquida, Strasbourg. The role of the lariat cap in translation initiation is studied with Martin Pospisek, Prague and Bruno Sargueil, Paris. The lab is a partner in the DSF-centre Non-coding RNA in Technology and Health (headed by Jan Gorodkin, Copenhagen). In this capacity, we are developing new sequencing-based methods for characterization of conserved structural RNA elements in the human genome. The centre has a strong bioinformatics component and one of the main goals is to correlate new ncRNAs with development of inflammatory disease.

Publications:

  • Vader, A., Nielsen, H. and Johansen, S. (1999) In vivo expression of a rRNA group I intron ORF involves polyadenylation and removal of a spliceosomal intron. EMBO J. 18, 1003-1013.
  • Nielsen, H., Westhof, E. and Johansen, S. (2005) An mRNA is capped with a 2, 5 lariat catalyzed by a group I-like ribozyme. Science 309, 1584-1589.
  • Beckert, B., *Nielsen, H., Einvik, C., Johansen, S. D., Westhof, E. and *Masquida, B. (2008) Molecular modelling of the GIR1 branching ribozyme gives new insight into evolution of structurally related ribozymes. EMBO J. 27, 667-78. *Shared senior authorship.