The goal of this study is to investigate how the properties of proteins are impacted by post-translational modifications (PTMs) associated with protein prenylation, specifically the proteolytic and carboxylmethylation events that typically follow isoprenylation. Most studies to date have investigated this issue using a select few reporters, including the Ras GTPases and the yeast a-factor mating pheromone. Our studies are bringing a new understanding to this issue by promoting a general view that the PTMs occurring to prenylated proteins are not necessarily coupled and are key regulators of protein function and localization. We have proposed two aims. One will investigate the coupling of PTMs using a set of prenylated protein reporters outside those previously studied. Our studies will challenge the conventional paradigm for how prenylated proteins are modified, which in turn will provide guidance to strategies aimed at interfering with protein prenylation and related downstream events as disease therapies.
The second aim will investigate the target specificities of the Rce1p and Ste24p proteases that act on prenylated proteins. Our studies will demonstrate that these proteases have very distinct enzymatic profiles, which will provide additional guidance on the specific targeting of these enzymes in disease therapies. We bring to bear on our investigations an exceptionally strong set of preliminary findings, the complementary expertise of several research groups, and a comprehensive molecular toolbox for the study of prenylated proteins and the proteases involved.
Many important signaling proteins, such as the Ras GTPases, are modified in coupled fashion by isoprenylation, proteolysis and carboxylmethylation. This research project will investigate the extent to which these three modifications, alone and in combination, impact protein function and localization. This research will also establish that one of the proteases involved in the production of prenylated proteins has much broader biological and disease relevance than previously appreciated.
| Berger, Brittany M; Kim, June H; Hildebrandt, Emily R et al. (2018) Protein Isoprenylation in Yeast Targets COOH-Terminal Sequences Not Adhering to the CaaX Consensus. Genetics 210:1301-1316 |
| Hampton, Shahienaz E; Dore, Timothy M; Schmidt, Walter K (2018) Rce1: mechanism and inhibition. Crit Rev Biochem Mol Biol 53:157-174 |
| Blanden, Melanie J; Suazo, Kiall F; Hildebrandt, Emily R et al. (2018) Efficient farnesylation of an extended C-terminal C(x)3X sequence motif expands the scope of the prenylated proteome. J Biol Chem 293:2770-2785 |
| Hildebrandt, Emily R; Arachea, Buenafe T; Wiener, Michael C et al. (2016) Ste24p Mediates Proteolysis of Both Isoprenylated and Non-prenylated Oligopeptides. J Biol Chem 291:14185-98 |
| Hildebrandt, Emily R; Cheng, Michael; Zhao, Peng et al. (2016) A shunt pathway limits the CaaX processing of Hsp40 Ydj1p and regulates Ydj1p-dependent phenotypes. Elife 5: |
| Mohammed, Idrees; Hampton, Shahienaz E; Ashall, Louise et al. (2016) 8-Hydroxyquinoline-based inhibitors of the Rce1 protease disrupt Ras membrane localization in human cells. Bioorg Med Chem 24:160-78 |
