Gene Expression
Dr G Hautbergue
I am working in Prof. Stuart Wilson’s laboratory on the understanding of human and viral messenger RNA nuclear export mechanisms, as well as on other research projects, including new techniques of messenger ribonucleo-particle purification and interaction of epithelial membrane proteins implicated in endometrial cancer and inflammatory diseases. For several years I have also been involved in supervising experiments of students/staff working in other biological disciplines (including Microbial, Plant, Developmental or Neurological Sciences) from a number of laboratories across MBB and the University.
Research synopsis
My long-standing interest is concerned with gene expression in Eukaryotes, in particular with study of molecular mechanisms controlling RNA polymerase II transcription as well as nuclear export of viral and cellular mRNA. My collaborators and I use various experimental approaches such as biochemistry, molecular and cellular biology as well as structural studies to unravel the functions of gene products and to characterise new unknown factors.
A general method to improve protein solubility and stability
Understanding how proteins or complexes work at molecular level requires purification of their activity, but poor solubility of the purified proteins is a common and challenging problem which often prematurely ends biochemical or structural projects. We developed a new method to improve protein solubility (up to 25 times) and stability using the physiological additives L-Arginine and L-Glutamate, and solved for the first time the atomic structures of a new class of conserved factors called mRNA export adaptors. Since, this method was applied successfully for the solubilisation of various proteins as well as for the determination of other NMR or X-ray structures by many research groups across the world.
Solution structures of mRNA export adaptors
Our solubilisation method allowed us to solve the NMR structures of several members of a distinct class of eukaryotic proteins called mRNA export adaptors (REF2-I, SRSF1/SF2/ASF RRM2, SRSF3/SRp20 and SRSF7/9G8). We are currently working on the structure of SRSF2/SC35. This family of proteins plays a key function in mRNA nuclear metabolism (described below), and is composed of one or two RNA Recognition Motifs (RRM) flanked by unstructured regions rich in Arginine/Glycine (RGG boxes) or Arginine/Serine (RS domains). In contrast to canonical RRM previously characterised, export adaptor factors display weak RNA-binding affinities which involve arginines in flexible regions together with contacts by the RRM domain and loops. This particular mode of RNA recognition is likely to reflect the cellular requirement for timed-association/dissociation of adaptors to on-going synthesis, processing and nuclear export of mRNA molecules.
Molecular mechanism(s) of human and viral mRNA nuclear export
Export adaptors were initially thought to bridge the interaction between the conserved nuclear export receptors TAP/NXF1/Mex67p which bind directly nucleoporins and processed RNA to trigger mRNA transport from the nucleus to the cytoplasm. Interestingly, our structural and functional analysis of export adaptors has shown that adaptors which also directly bind RNA stimulate in turn RNA hand-over to TAP upon mutually exclusive interactions, providing a control mechanism which prevent deleterious nuclear export of unprocessed mRNA.
In contrast to the yeast Yra1p export adaptor, the human orthologue REF/ALY is not essential while both human and yeast DEAD-box RNA helicases UAP56/Sub2p which interact directly with REF/ALY/Yra1p are conserved and essential, suggesting the existence of additional UAP56-dependent mRNA export adaptors in higher Eucaryotes. The characterisation of the interaction domain between REF/ALY and UAP56 led to the discovery of several new export adaptors including a protein of unknown function that we named UIF (UAP56-Interacting Factor) and is recruited to processing mRNA via the FACT chromatin remodelling complex, coupling for the first time chromatin remodelling to mRNA nuclear export in higher Eucaryotes.
Furthermore, we found that Herpes viruses hijack the cellular human machinery to allow efficient nuclear export of their intronless RNA genome by encoding specific viral proteins HVS ORF57/ICP27 which bind RNA and cellular adaptors REF/ALY and UIF. We are also currently investigating the mechanisms controlling the nuclear export of Influenza RNA genome.
Selected publications
Jackson B.R., Boyne J.R., Noerenberg M., Taylor A., Blackbourn D.J., Hautbergue G.M., Walsh M.J., Wilson S.A. and Whitehouse A. (2011) UIF-mediated recruitment of the cellular hTREX complex to KSHV intronless mRNAs. PLoS Pathog. 7 (7):e1002138.
Van Hateren N.J., Das R.M., Hautbergue G.M., Borycki A.G., Placzek M., Wilson S.A. (2011) FatJ acts via the Hippo mediator Yap1 to restrict the size of neural progenitor cell pools. Development 138 (10):1893-1902.
Tunnicliffe R.B., Hautbergue G.M., Kalra P., Jackson B.R., Whitehouse A., Wilson S.A., Golovanov A.P. (2011) Structural basis for the recognition of cellular mRNA export factor REF by herpes viral proteins HSV-1 ICP27 and HVS ORF57. PLoS Pathog. 7 (1):e1001244.
Hung M.-L., Hautbergue G.M., Snijders A.P., Dickman M.J., Wilson S.A. (2010) Arginine methylation of REF/ALY promotes efficient handover of mRNA to TAP/NXF1. Nucleic Acids Res. 38 (10):3351-61.
Walsh M.J., Hautbergue G.M., Wilson S.A. (2010) Structure and function of mRNA export adaptors. Review. Biochem Soc Trans. 38:232-236.
Hautbergue G.M., Hung M.-L., Walsh M.J., Snijders A.P., Chang C.-T., Jones R., Ponting C.P., Dickman M.J., Wilson S.A. (2009) UIF, a new mRNA export adaptor that works together with REF/ALY, requires FACT for recruitment to mRNA. Curr Biol. 19 (22):1918-1924.
Hautbergue G.M., Hung M.-L., Golovanov A.P., Lian L.-Y. and Wilson S.A. (2008) Mutually exclusive interactions drive handover of mRNA from export adaptors to TAP. Proc Natl Acad Sci USA 105 (13): 5154-5159.
Hautbergue G.M. and Golovanov A.P. (2008) Increasing the sensitivity of cryoprobe protein NMR experiments by using the sole low-conductivity arginine glutamate salt. J Magn Reson 191 (2): 335-339.
Tintaru A.M.*, Hautbergue G.M.*, Hounslow A.M., Hung M.L., Lian L.-Y., Craven C.J. and Wilson S.A. (2007) Structural and functional analysis of RNA and TAP binding to SF2/ASF. EMBO Rep. 8 (8): 756-762. * Joint first authors
Hargous Y.*, Hautbergue G.M.*, Tintaru A.M., Skrisovska L., Golovanov A.P., Stevenin J., Lian L.-Y., Wilson S.A. and Allain F.H-T. (2006) Molecular basis of RNA recognition and TAP binding by the SR proteins SRp20 and 9G8. EMBO J. 25 (21): 5126-5137. * Joint first authors
Golovanov A.P.*, Hautbergue G.M.*, Tintaru A.M., Lian L.-Y. and Wilson S.A. (2006) The solution structure of REF2-I reveals interdomain interactions and regions involved in binding mRNA export factors and RNA. RNA 12 (11): 1933-1948. * Joint first authors
Williams B.J.L., Boyne J.R., Goodwin D.J., Roaden L., Hautbergue G.M., Wilson S.A. and Whitehouse A. (2005) The prototype g-2 herpesvirus nucleocytoplasmic shuttling protein, ORF 57, transports viral RNA through the cellular mRNA export pathway. Biochemical J. 387: 295-308.
Bouchoux C., Hautbergue G., Grenetier S., Carles C., Riva M. and Goguel V. (2004) CTD kinase I is involved in RNA polymerase I transcription. Nucleic Acids Res. 32 (19): 5851-5860.
Golovanov A.P., Hautbergue G.M., Wilson S.A. and Lian L.-Y. (2004) A simple method for improving protein solubility and long-term stability. J. Am. Chem. Soc. 126 (29): 8933-8939.
Hautbergue G. and Goguel V. (2001) Activation of the Cyclin-Dependent Kinase CTDK-I requires the heterodimerization of two unstable subunits. J. Biol. Chem. 276 (11): 8005-8013.
Hautbergue G. and Goguel V. (1999) The yeast C-type cyclin Ctk2p is phosphorylated and rapidly degraded by the ubiquitin-proteasome pathway. Mol. Cell. Biol. 19 (4): 2527-2534.