Jeroen Roelofs

Research Focus

The ability to degrade specific proteins is essential for many cellular events, such as cell cycle progression, DNA repair, and many signal transduction pathways. In eukaryotes a large group of proteins (in humans, e.g. more than 650 proteins) is involved in selecting proteins destined for degradation by marking them with an ubiquitin tag.  Most of these ubiquitinated proteins are degraded by a complex protease, the proteasome. Failures in the Ubiquitin-Proteasome System (UPS) have been associated with neurodegenerative diseases, cancers and other human diseases.

The proteasome consists of two sub-complexes, the core particle (CP) and the regulatory particle (RP) and has several factors that can associate with it. The 28 subunits of the CP form a cylindrical shaped structure with proteolytic sites located on the inner surface. The CP can bind RP at either side of the cylinder. The 19 subunits of the RP are involved in recognizing, unfolding and threading of ubiquitinated substrates into the CP chamber.

The research in my lab is driven by a desire to understand the proteasome. How does this molecular machine work? What role do the different subunits play? How do the 66 proteins that form the proteasome come together and form one functional unit? Previously I identified several proteins that work as chaperones, assisting in the assembly of the proteasome. One project in my lab continues to study how the proteasome assembles and in what way the chaperones assist in this process. For this and other studies in the lab we use the yeast Saccharomyces Cerevisiae (most proteasome subunits as well as many mechanistic details are conserved between yeast and humans), as well as mammalian tissue culture.  The studies include biochemical and cell biological methods (including fluorescent imaging techniques) as well as yeast genetics.

 

Selected Research Publications

Lee, S.Y., A. De la Mota-Peynado,and J. Roelofs. 2011. Loss of Rpt5 protein interactions with the core particle and Nas2 protein causes the formation of faulty proteasomes that are inhibited by Ecm29 protein. Journal of  Biological Chemistry  286(42):36641-51.

Bedford, L., S. Paine, P.W. Sheppard, R.J. Mayer, and J. Roelofs. 2010 Assembly, structure, and function of the 26S proteasome.  Trends Cell Biology 20(7):391-401.

Park, S., J. Roelofs, W. Kim, J. Robert, M. Schmidt, S.P. Gygi and D. Finley. 2009. Hexameric assembly of the proteasomal ATPases is templated through their C-termini. Nature 459: 861-865.
N&V in Nature (Vol. 459, p787-788); Highlighted in Nature Reviews Molecular Cell Biology (Vol. 10, p442) & Cell (Vol.138, p25-28)

Roelofs, J., S. Park, W. Haas, G. Tian, B. Lee, F. Zhang, Y. Shi, S.P. Gygi and D. Finley. 2009. Chaperone-mediated pathway of proteasome regulatory particle assembly. Nature 459: 866-70.
N&V in Nature (Vol. 459, p787-788); Highlighted in Nature Reviews Molecular Cell Biology (Vol. 10, p442) & Cell (Vol.138, p25-28)

Kleijnen, MF*, J. Roelofs*, S. Park, N.A. Hathaway, M. Glickman, R.W. King, and D. Finley. 2007. Stability of the proteasome can be regulated allosterically through engagement of its proteolytic active sites. Nature Structural & Molecular Biology 14: 1180-88.
* equal contribution; Highlighted in The Journal of Cell Biology (Vol. 179, No. 6, p1086)

Peng, J., D. Schwartz, J.E. Elias, C.C. Thoreen, D. Cheng, G. Marsischky, J. Roelofs, D. Finley, and S.P. Gygi. 2003. A proteomics approach to understanding protein ubiquitination. Nature Biotechnology 21: 921-6.

Roelofs, J. and P.J.M. Van Haastert. 2002. Characterization of two unusual guanylyl cyclases from dictyostelium. Journal of Biological Chemistry 277: 9167-74.

Roelofs, J. and P.J.M. Van Haastert. 2002. Deducing the origin of soluble adenylyl cyclase, a gene lost in multiple lineages. Molecular Biology and Evolution 19: 2239-46.

Roelofs, J.*, M. Meima*, P. Schaap, and P.J.M. Van Haastert. 2001. The Dictyostelium homologue of mammalian soluble adenylyl cyclase encodes a guanylyl cyclase. EMBO Journal 20: 4341-8.
* equal contribution

Roelofs, J. and P.J.M. Van Haastert. 2001. Genes lost during evolution. Nature 411: 1013-4.

All publications Jeroen Roelofs at Pubmed