CRM1 mediates the nuclear export of YTHDF2.

Area of Science:

• Molecular Biology
• Epigenetics
• RNA Biology

Background:

• Protein localization is critical for cellular function.
• YTHDF2 (YTH domain-containing family protein 2) is an N6-methyladenosine (m6A) reader that shuttles between the cytoplasm and nucleus via an uncharacterized mechanism.
• Dysregulation of YTHDF2 localization is implicated in various diseases.

Purpose of the Study:

• To elucidate the mechanism governing YTHDF2's nucleocytoplasmic transport.
• To identify the specific sequence responsible for YTHDF2 nuclear export.
• To investigate the functional consequences of impaired YTHDF2 localization.

Main Methods:

• Identification and mutation of a putative nuclear export sequence (NES) in YTHDF2.
• Co-immunoprecipitation assays to assess YTHDF2-CRM1 interaction.
• Inhibition of CRM1 using leptomycin B and CRM1 knockdown experiments.
• Tethering reporter assays to evaluate YTHDF2's mRNA degradation activity.

Main Results:

• A functional NES was identified in YTHDF2, mediating its nuclear export.
• NES-mutant YTHDF2 exhibited nuclear accumulation.
• Wild-type YTHDF2, but not the NES-mutant, interacted with the nuclear export receptor CRM1.
• CRM1 inhibition or knockdown blocked YTHDF2 nuclear export.
• NES mutation impaired YTHDF2's mRNA degradation function.

Conclusions:

• The identified NES is crucial for YTHDF2's regulated nuclear export via the CRM1 pathway.
• Altered YTHDF2 localization impacts its mRNA degradation activity.
• These findings offer mechanistic insights into YTHDF2 regulation and potential therapeutic strategies for YTHDF2-related diseases.