Phosphorylation impacts GLE1 nuclear localization and association with DDX1.

Area of Science:

• Molecular Biology
• Cell Biology
• Gene Regulation

Background:

• Gle1 is a key regulator of gene expression, influencing transcription, mRNA export, and translation.
• Understanding Gle1's role in stressed cells requires investigating its post-translational modifications.

Purpose of the Study:

• To investigate the function of Gle1 phosphorylation at threonine 102 (T102) in human cells under stress.
• To elucidate the impact of Gle1 phosphorylation on its cellular localization and interactions.

Main Methods:

• Generation of specific antibodies against phosphorylated Gle1 (Gle1-pT102).
• In vitro kinase assays to study T102 phosphorylation.
• Indirect immunofluorescence microscopy to determine Gle1 localization.
• Immunoprecipitation to identify Gle1 interacting partners.

Main Results:

• T102 phosphorylation acts as a priming event for further Gle1 phosphorylation.
• Phosphorylated Gle1 shifts from predominantly nuclear to more cytoplasmic localization under stress.
• Gle1-pT102 co-immunoprecipitates with DDX1 in a phosphatase-sensitive manner.
• Disruption of nucleocytoplasmic shuttling increases Gle1-pT102 and DDX1 association.

Conclusions:

• Gle1 phosphorylation at T102 influences its cellular distribution and nuclear functions, particularly in transcription termination.
• Phosphorylation may reduce Gle1's nucleocytoplasmic shuttling or enhance its binding to nuclear partners.
• This study provides insights into Gle1 regulation during cellular stress.