Scope of the research programme
Protein fatty acylation is the modification of proteins by fatty acids myristate and palmitate mostly. Protein fatty acylation is a very unique protein modification that impacts on virtually every aspect of cellular life including the regulation of membrane targeting, apoptosis, cell proliferation, protein-protein interaction, protein stability and protein secretion. Fatty acylated proteins are surprisingly abundant and form a large and understudied protein family, which is divided into two groups: myristoylation and palmitoylation. It is estimated that at least 5% of nuclear encoded proteins are either myristoylated or palmitoylated and yet little is known about the biology of protein fatty acylation.
Many acylated proteins are linked to the disease state. Examples include: Src, Ras and Wnt oncogenes are involved in cancer progression while acylated HIV Gag and GP160 are involved in the HIV life cycle and AIDS. In addition, G-protein coupled receptors, which ar epalmitoylated are involved in a variety of patho-physiological conditions such as hypertension (e.g. β-adrenergic and vasopressin receptors). Studying protein fatty acylation is therefore highly clinically relevant. Recently, our efforts have focused on apoptosis and cancer. More specifically, we study the role of protein fatty acylation across the full spectrum of signal transduction. Simply put, signal transduction is the movement of a signal from outside to inside the cell. It often results in changes in gene expression, which in turn, alters cellular metabolism. In addition, we study the involvement of palmitoylation in the regulation of gene expression and enzymatic activity resulting in the fine-tuning of mitochondrial metabolism.
Detection of fatty acylated proteins, chemical biology leading the way
Progress in the study of fatty acylation has been hampered by the lack of rapid detection methods. Until very recently, detection of fatty acylated proteins relied on the tedious and hazardous incorporation of radioactive [3H]-fatty acids into proteins followed by lengthy fluorographic exposures (often months). Subsequently, as a post-doctoral fellow, I was part of team that developed the use of [125I]-iodofatty acids as labels, which reduced exposure time significantly but these were also hazardous and not commercially available. Recent breakthroughs in our laboratory and others have led to major improvements in detection and identification of fatty acylated proteins using chemical biology (e.g. publications 29 and 33 below). Using these methods, we can now easily readily study protein fatty acylation in cells and even in vivo (33).
Health relevance and applications
Many years of research efforts on the implications of myristoylation in cancer and apoptosis have led to the discovery that blood cancer cells are extremely vulnerable to myristoylation inhibitors. This work on lymphoma and leukemia is now being submitted for publication. In order to translate this discovery into a new potential therapy that could benefit lymphoma and leukemia patients, we formed a new company named PACYLEX (Protein ACYLation EX) Pharmaceuticals Inc. (See www.pacylex.com for more information on our therapeutic strategy).
Past and Current Funding
Our work is typically funded by: The Canadian Institute of Health Research, Alberta Cancer Foundation, the Heart and Stroke Foundation of Alberta, NWT and Nunavut and now an Industrial Research Assistance Program (IRAP) grant from the National Research Council of Canada.
44*. Dale D.O. Martin, Ryan J. Heit, Megan C. Yap, Michael W. Davidson, Michael R. Hayden and Luc G. Berthiaume (2014) “Identification of a posttranslationally myristoylated autophagy inducing domain released by caspase cleavage of Huntingtin” Human Molec. Genet. 23(12):3166-79. doi: 10.1093/hmg/ddu027. Epub 2014 Jan 23. (*Cover page of the journal)
43*. Berthiaume, Luc G. (2013) “Wnt acylation: Seeing is believing” Nature Chemical Biology Published online 24 November 2013 doi:10.1038/nchembio.1414 (*Invited Commentary)
42*. Emily M. Lynes, Arun Raturi, Marina Shenkman, Carolina Ortiz Sandoval, Megan C. Yap, Jiahui Wu, Aleksandra Janowicz, Nathan Myhill, Matthew D. Benson, Robert E. Campbell, Luc G. Berthiaume, Gerardo Z. Lederkremer and Thomas Simmen “Palmitoylation is the Switch that Assigns Calnexin to Quality Control or ER Calcium Signaling” Journal Cell Science (in press, 10 July 2013, Epub ahead of print) *Highlighted as featured paper in JCS
41. Gu HM, Li G, Gao X, Berthiaume LG, Zhang DW (2013) “Characterization of palmitoylation of ATP binding cassette transporter G1: Effect on protein trafficking and function” Biochim Biophys Acta. 1831:1067-1078.
40. Perinpanayagam MA, Beauchamp E, Martin DD, Sim JY, Yap MC, Berthiaume LG (2013) “Regulation of co- and post-translational myristoylation of proteins during apoptosis: interplay of N-myristoyltransferases and caspases” FASEB J. 27: 811-21.
39. Dale D.O. Martin, Chrisselle Y. Ahpin, Ryan J. Heit, Maneka A. Perinpanayagam, Megan C. Yap, Richard A. Veldhoen, Ing Swie Goping and Luc G. Berthiaume (2012) “Tandem reporter assay for myristoylated proteins post-translationally (TRAMPP) identifies novel substrates for post-translational myristoylation: PKC epsilon; a case study” FASEB J 26:13-28.
38. Emily Lynes, Michael Bui, Megan C. Yap, Lars Ellgaard, Luc G. Berthiaume and Thomas Simmen (2011) “Palmitoylation Mediates the Enrichment of TMX and Calnexin on the Mitochondria-Associated Membrane (MAM)” EMBO J.,31:457-70.
36. Martin, D.D.O. , Beauchamp, E. and Berthiaume, L.G. (2011) “Post-translational myristoylation: fat matters in cellular life and death” Biochimie 93, 18-31.
34. Morris A. Kostiuk, Bernd O. Keller and Luc G. Berthiaume. (2010) “Palmitoylation of HMG-CoA synthase promotes its interaction with PPARa and enhances transcription from the HMG-CoA synthase PPRE: a novel co-activation mechanism” (In press. FASEB J.)
33. Megan C. Yap*#, Morris A. Kostiuk*, Dale D. O. Martin, Maneka A. Perinpanayagam, Pieter G. Hak, Anjaiah Siddam, Janaki R. Majjigapu, Gurram Rajaiah, Bernd O. Keller, Jennifer A. Prescher, Peng Wu, Carolyn R. Bertozzi, John R. Falck and Luc G. Berthiaume (2010) “Detecting the palmitoylation of endogenous proteins with w-alkynyl-palmitate in vitro, in cultured cells and in vivo using click chemistry: H- and N-Ras as a case study” J. Lipid Res. 51, 1566-1580)
(* these authors contributed equally, # our technician)
31. Meyer-Schaller N, Chou YC, Sumara I, Martin DD, Kurz T, Katheder N, Hofmann K, Berthiaume LG, Sicheri F, Peter M. (2009) “The human Dcn1-like protein DCNL3 promotes Cul3 neddylation at membranes”. Proc. Natl. Acad. Sci. U. S. A. 106:12365-70.
30. Kostiuk, M.A, Bernd O. Keller and Berthiaume, L.G. (2009) “Non-radioactive detection of palmitoylated mitochondrial proteins using an azido-palmitate analogue” Methods in Enzymology 457:149-165.
29. Martin, Dale D.O., Vilas, Gonzalo L., Prescher, Jennifer A., Rajaiah, Gurram, Falck, John R., Bertozzi, Carolyn R., Berthiaume, Luc G. (2008) “Rapid detection, discovery and identification of post-translationally myristoylated proteins during apoptosis using a bioorthogonal azidomyristate analogue.” FASEB J. 22, 797-806.
28. Morris A. Kostiuk, Maria M. Corvi, Bernd O. Keller, Greg Plummer, Jennifer A. Prescher, Matthew J. Hangauer, Carolyn R. Bertozzi, Gurram Rajaiah, John R. Falck and Luc G. Berthiaume (2008) “Identification of palmitoylated mitochondrial proteins using a bio-orthogonal azido-palmitate analogue” FASEB J. 22, 721-732.
27. M. Sariahmetoglu, B.D. Crawford, H. Leon, J. Sawicka, L. Li, B.J. Ballermann, C. Holmes, L.G. Berthiaume, A. Holt, G. Sawicki and R. Schulz (2007) "Matrix metalloprotease-2 is regulated by phosphorylation" FASEB J., 21, 2486-2495.
26*. Gonzalo L Vilas, Maria M Corvi, Greg J Plummer, Andrea M Seime, Gareth R Lambkin and Luc G Berthiaume (2006) “Post-translational myristoylation of caspase-activated PAK2 potentiates late apoptotic events” Proc. Natl. Acad. Sci. U.S.A. 103, 6542-6547.
*Cited in the Faculty of 1000
N.B. The names of the Berthiaume lab trainees are underlined.