UC San Diego

Gle1 is an evolutionary conserved protein involved in both mRNA export and translation. A recent study linked mutations in Gle1 with recessive and fatal motor neuron diseases characterized by ventral horn motor neuron degeneration before birth. This is particularly interesting in light of a growing pool of evidence indicating that a common denominator in many motor neuron disorders is defects in mRNA regulation. To investigate the role of Gle1 in motor neuron development, we used chick and mouse models to develop tools for examining Gle1s̀ expression, localization, biochemical interactions, and altered activity when mutated. We have confirmed the presence of Gle1 transcripts in a variety of cell types and stages of development, including during motor neuron development, and we generated Gle1-Flag fusion constructs to study Gle1 localization and biochemistry following failure of commercial antibodies to reliably detect Gle1 through immunohistochemistry and immunoblotting. Overexpressing mutant Gle1 does not appear to noticeably affect the development of motor neurons in chick, suggesting that the mutant protein does not cause disease through a gain of function. To study the effects of Gle1 loss on development, we generated a mouse line expressing a Gene-trap allele in which Gle1 is created as a truncated protein linked to [Beta]-Geo. As animals homozygous for this allele appear nonviable, we selected a rescue strategy in which we will express Gle1 from the ROSA26 locus in a Gene-trap background, allowing us to examine the specific effects of Gle1 mutation on motor neuron survival and function