Welcome to the Brodersen Lab
Small RNAs in plants: fundamental regulators of gene expression
Small silencing RNAs are the hallmark of a collection of gene regulatory mechanisms known as RNA silencing. In RNA silencing, the small (20-30 nucleotide long) RNAs act as specificity determinants that use base pairing to guide repressive protein complexes to complementary RNA molecules. This simple, versatile mehanism is of tremendous importance in regulation of mRNAs important for plant and animal development and stress responses, particularly via a specific class of small RNAs called microRNAs (miRNAs).
In plants and animals, small RNA based mechanisms are also at the heart of epigenetic silencing mechanisms that act to limit transposon activity and thereby contribute to the maintenance of genome stability. In a related process, RNA silencing is also being employed as an RNA based immune system to combat infections by RNA viruses in plants and insects. It is an important objective of our research to understand how the RNA silencing mechanism is coupled to protein-based sensing of pathogens via immune receptors. This project is starting January 2014, and is supported by a Sapere Aude grant from the Danish Council for Independent Research. More details about this project can be found at my Sapere Aude home page.
Our group also maintains a strong focus on understanding the mechanistic basis of miRNA function in plants. We make extensive use of genetic screens coupled to next-generation DNA sequencing to identify new components involved in discrete steps of the pathway. We also employ biochemical methods to study protein complexes with important functions in the pathway. We have previously shown that a miRNA effector complex is associated with a membrane compartment, and are studying how the membrane association occurs and what its functional role is. We are also interested in elucidating how miRNAs bring about translational repression of mRNA in plants, and understanding the relation of this mode of regulation to mRNA degradation.
The group is supported by:
Novo Nordisk Foundation
European Research Council
Danish Council for Independent Research (DFF)
Brdr Hartmann Fonden
Sjögren L, Floris M, Barghetti A, Völlmy F, Linding R, Brodersen P. Farnesylated Heat Shock Protein 40 is a component of membrane-bound RISC in Arabidopsis. J Biol Chem Sep 7, 2018. DOI: 10.1074/jbc.RA118.003887
Arribas-Hernández L, Bressendorff S, Hansen MH, Poulsen C, Erdmann S, Brodersen P. An m6A-YTH Module Controls Developmental Timing and Morphogenesis in Arabidopsis. Plant Cell. May 30, 2018. doi: 10.1105/tpc.17.00833
Heat-shock protein 40 is the key farnesylation target in meristem size control, abscisic acid signaling, and drought resistance. Barghetti A, Sjögren L, Floris M, Paredes EB, Wenkel S, Brodersen P. Genes Dev. 2017 Nov 15;31(22):2282-2295. doi: 10.1101/gad.301242.117. Epub 2017 Dec 21.
Arribas-Hernández L, Marchais A, Poulsen C, Haase B, Hauptmann J, Benes V,Meister G, Brodersen P. The slicer activity of ARGONAUTE1 is required specifically for the phasing, not production, of trans-acting short interfering RNAs in Arabidopsis. Plant Cell. 2016 July; 28 (7): 1563-1580. Epub June 27, 2016.
Branscheid A, Marchais A, Schott G, Lange H, Gagliardi D, Andersen SU, Voinnet O, Brodersen P. SKI2 mediates degradation of RISC 5′-cleavage fragments and prevents secondary siRNA production from miRNA targets in Arabidopsis. Nuc Acids Res. 2015 December 15; 43(22): 10975–10988. Epub October 12, 2015.