Nonsense mediated decay (NMD) leads to the degradation of pre-mRNAs which contain a premature termination codon (PTC). Recent reports suggest that nuclear NMD may involve a pre-splicing proofreading mechanism, nuclear translation. We propose that NMD affects the rate of splicing of the introns upstream or downstream from exons containing PTCs. Quantitative RT-PCR will be used to measure the abundance of introns in wildtype, nonsense codon-containing, and missense-codon containing precursor mRNAs since it has been proven mathematically that the introns which are excised most quickly will be less abundant within the pre-mRNA population. Two mRNAs will be tested: the somatically rearranging Ig-mu and the non-rearranging DHFR. Finally, several different systems will be established in which only nuclear or cytoplasmic translation can occur. Then, the rate and order of intron removal will be tested under conditions which will demonstrate that any change in splicing is due to nuclear translation.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32GM067478-03
Application #
6857050
Study Section
Special Emphasis Panel (ZRG1-F05 (20))
Program Officer
Dearolf, Charles R
Project Start
2003-04-15
Project End
2006-06-02
Budget Start
2005-04-15
Budget End
2006-06-02
Support Year
3
Fiscal Year
2005
Total Cost
$35,814
Indirect Cost
Name
Yale University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
043207562
City
New Haven
State
CT
Country
United States
Zip Code
06520
Lytle, J Robin; Yario, Therese A; Steitz, Joan A (2007) Target mRNAs are repressed as efficiently by microRNA-binding sites in the 5'UTR as in the 3'UTR. Proc Natl Acad Sci U S A 104:9667-72
Lytle, J Robin; Steitz, Joan A (2004) Premature termination codons do not affect the rate of splicing of neighboring introns. RNA 10:657-68