MKRN2 Physically Interacts with GLE1 to Regulate mRNA Export and Zebrafish Retinal Development
Eric J. Wolf,
Amanda Miles,
Eliza S. Lee,
Syed Nabeel-Shah,
Jack F. Greenblatt,
Alexander F. Palazzo,
Vincent Tropepe,
Andrew Emili
Affiliations
Eric J. Wolf
Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
Amanda Miles
Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
Eliza S. Lee
Department of Biochemistry, University of Toronto, Toronto, ON, Canada
Syed Nabeel-Shah
Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
Jack F. Greenblatt
Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
Alexander F. Palazzo
Department of Biochemistry, University of Toronto, Toronto, ON, Canada
Vincent Tropepe
Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada; Corresponding author
Andrew Emili
Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada; Center for Network Systems Biology, Boston University, Boston, MA, USA; Corresponding author
Summary: The mammalian mRNA nuclear export process is thought to terminate at the cytoplasmic face of the nuclear pore complex through ribonucleoprotein remodeling. We conduct a stringent affinity-purification mass-spectrometry-based screen of the physical interactions of human RNA-binding E3 ubiquitin ligases. The resulting protein-interaction network reveals interactions between the RNA-binding E3 ubiquitin ligase MKRN2 and GLE1, a DEAD-box helicase activator implicated in mRNA export termination. We assess MKRN2 epistasis with GLE1 in a zebrafish model. Morpholino-mediated knockdown or CRISPR/Cas9-based knockout of MKRN2 partially rescue retinal developmental defects seen upon GLE1 depletion, consistent with a functional association between GLE1 and MKRN2. Using ribonomic approaches, we show that MKRN2 binds selectively to the 3′ UTR of a diverse subset of mRNAs and that nuclear export of MKRN2-associated mRNAs is enhanced upon knockdown of MKRN2. Taken together, we suggest that MKRN2 interacts with GLE1 to selectively regulate mRNA nuclear export and retinal development.
