Nuclear export of messenger RNAs (mRNAs) and their subsequent translation are essential steps in the gene expression pathway and impact all aspects of cell physiology. There is a growing body of evidence suggesting that dysfunctional mRNA trafficking contributes directly to motor neuron diseases (MND). This is further supported by the recent genetic linkage of mutant human GLE1 alleles to the fetal motor neuron disease: Lethal Congenital Contracture Syndrome (LCCS-1). Gle1 is an essential mRNA export factor, conserved from yeast to humans. Yeast Gle1 plays an important role in both translation initiation and termination. Sequence analysis of genomic DNA from LCCS-1 cases identified a mutation that generates an illegitimate splice acceptor site within the third intron of GLE1. This specific mutation (FINMajor) results in an insertion of three amino acid residues (PFQ) in the amino-terminal domain of hGle1. In preliminary studies a novel function for hGle1 in cytoplasmic mRNA trafficking has been found. Strikingly, the FINMajor mutation may disrupt hGle1's function in trafficking. The goal of this proposal is to elucidate the functional consequence of the FINMajor mutant protein in mammalian cells. The two aims proposed will define the molecular consequence of the FINMajor mutation.
In Aim I, studies will be done to define hGle1 as a component of the cytoplasmic mRNA trafficking machinery.
In Aim II, a novel hGle1 knockdown, and add-back model system will be developed. With this experimental model, cell biology and biochemical assays will be used to investigate if the FINMajor mutant protein disrupts mRNA trafficking. The long-term goal is to molecularly define the neuronal role for hGle1 in the pathogenesis of the deleterious disease LCCS-1

Public Health Relevance

Gle1 is positioned to regulate multiple steps during mRNA metabolism and gene expression. By defining the molecular functional consequence of the FINMajor mutation, we will elucidate the importance of RNA metabolism in motor neuron disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
5F31NS070431-02
Application #
8261951
Study Section
Special Emphasis Panel (ZRG1-F03A-F (20))
Program Officer
Gubitz, Amelie
Project Start
2011-03-01
Project End
2014-02-28
Budget Start
2012-03-01
Budget End
2013-02-28
Support Year
2
Fiscal Year
2012
Total Cost
$26,884
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37212
Folkmann, Andrew W; Dawson, T Renee; Wente, Susan R (2014) Insights into mRNA export-linked molecular mechanisms of human disease through a Gle1 structure-function analysis. Adv Biol Regul 54:74-91
Folkmann, Andrew W; Collier, Scott E; Zhan, Xiaoyan et al. (2013) Gle1 functions during mRNA export in an oligomeric complex that is altered in human disease. Cell 155:582-93
Hodge, Christine A; Tran, Elizabeth J; Noble, Kristen N et al. (2011) The Dbp5 cycle at the nuclear pore complex during mRNA export I: dbp5 mutants with defects in RNA binding and ATP hydrolysis define key steps for Nup159 and Gle1. Genes Dev 25:1052-64