Nonsense mutations inactivate gene function by promoting synthesis of truncated polypeptides and accelerating mRNA decay. These mutations are a significant cause of genetic disorders, giving rise to 15- 30% of all disease-causing alleles. Recent studies have shown that the antibiotic, gentamicin, can suppress translation termination at premature nonsense codons and produce limited but functionally significant quantities of essential proteins in mouse models of cystic fibrosis and muscular dystrophy. While this has led to initial clinical evaluations of gentamicin therapy in human inherited disorders, long-term application of this approach is compromised by the considerable adverse effects of this drug. PTC Therapeutics, Inc. (PTC) has pursued the concept of a pharmaceutical approach to treating diseases caused by nonsense mutations and has identified a novel, low molecular weight compound (PTC124) that is considerably more potent than gentamicin in both cell and animal models. PTC124 has the potential for near-term broad application in numerous genetic disorders, but such widespread utility requires mechanism of action analyses which demonstrate that it: i) promotes insertion of near-cognate tRNAs at premature termination codons; ii) principally targets premature translational termination, not normal translational termination; iii) has limited host-transcriptional effects on non-targeted mRNAs; iv) does not elicit toxic side effects in whole animals; tnd v) promotes nonsense suppression in additional animal models of disease states. This fast-track STTR proposal describes molecular biological approaches to all of these issues. In Phase I, we will use cultured =ells to address items i-iii and to establish the technological approaches required for addressing the remaining issues in animal models in Phase II. More specifically, we will treat HeLa cells with PTC124 and: I) define the events promoting nonsense suppression and II) determine whether PTC124-mediated nonsense suppression has global consequences for cellular mRNA decay and translation.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Small Business Technology Transfer (STTR) Grants - Phase II (R42)
Project #
5R42HD048137-03
Application #
7234051
Study Section
Special Emphasis Panel (ZRG1-SSS-Y (10))
Program Officer
Oster-Granite, Mary Lou
Project Start
2004-09-23
Project End
2008-05-19
Budget Start
2007-05-20
Budget End
2008-05-19
Support Year
3
Fiscal Year
2007
Total Cost
$444,298
Indirect Cost
Name
Ptc Therapeutics, Inc.
Department
Type
DUNS #
124371951
City
South Plainfield
State
NJ
Country
United States
Zip Code
07080
Peltz, Stuart W; Welch, Ellen M; Trotta, Christopher R et al. (2009) Targeting post-transcriptional control for drug discovery. RNA Biol 6:329-34
He, Feng; Amrani, Nadia; Johansson, Marcus J O et al. (2008) Chapter 6. Qualitative and quantitative assessment of the activity of the yeast nonsense-mediated mRNA decay pathway. Methods Enzymol 449:127-47
Amrani, N; Dong, S; He, F et al. (2006) Aberrant termination triggers nonsense-mediated mRNA decay. Biochem Soc Trans 34:39-42
Jacobson, Allan (2005) The end justifies the means. Nat Struct Mol Biol 12:474-5