The RNA Exosome Adaptor ZFC3H1 Functionally Competes with Nuclear Export Activity to Retain Target Transcripts

Area of Science:

• Molecular Biology
• Cell Biology
• RNA Biology

Background:

• Mammalian genomes produce numerous RNA transcripts, many rapidly degraded by the nuclear RNA exosome.
• The nuclear exosome plays a critical role in RNA quality control and turnover.

Purpose of the Study:

• To investigate the consequences of impaired nuclear exosome function on RNA localization.
• To identify factors involved in the nuclear retention of polyadenylated (pA+) RNA.

Main Methods:

• Co-localization studies to examine the association of pA+ RNA with nuclear structures and proteins.
• Analysis of RNA export in cells with depleted exosome co-factors.

Main Results:

• Loss of nuclear exosome function results in the formation of nuclear foci containing pA+ RNA.
• These foci are enriched with PAXT connection components, notably ZFC3H1.
• ZFC3H1 depletion leads to cytoplasmic export of pA+ RNAs, dependent on AlyREF.

Conclusions:

• ZFC3H1 acts as a key factor for nuclear retention of pA+ RNA.
• This retention mechanism counteracts the nuclear export of specific RNA transcripts.