Selective recognition of PTRE1 transcripts mediated by protein-protein interaction between the m⁶A reader ECT2 and...

Area of Science:

• Molecular Biology
• RNA Biology
• Plant Science

Background:

• N6-methyladenosine (m6A) is a key RNA modification in eukaryotes.
• m6A readers, like Arabidopsis ECT2, regulate gene expression.
• ECT2 previously shown to upregulate proteasome components.

Purpose of the Study:

• Elucidate the mechanism of selective m6A target recognition by ECT2.
• Investigate how ECT2 interacts with its targets, PTRE1 and proteasome subunits.
• Determine the role of protein-protein interactions in ECT2-mediated gene regulation.

Main Methods:

• Co-immunoprecipitation to confirm protein-protein interactions.
• Analysis of ECT2 mutants with deletions in protein interaction or m6A-binding domains.
• Reporter assays to assess the impact of novel protein-binding domains.

Main Results:

• ECT2 physically interacts with PTRE1 and 20S proteasome subunits on the ribosome.
• Interaction involves the N-terminus of PTRE1, suggesting binding to nascent polypeptides.
• ECT2's protein interaction domain is crucial for mRNA binding; m6A-binding site mutations do not affect protein interactions.
• Introducing a novel protein-binding domain enhanced transcript levels of interacting proteins.
• PTRE1 protein interaction enhances ECT2 binding to PTRE1 m6A mRNAs during translation.

Conclusions:

• ECT2 utilizes protein-protein interactions to enhance its binding to specific m6A-modified mRNAs during translation.
• This mechanism contributes to the selective recognition of m6A targets by readers.
• The findings provide novel insights into post-transcriptional regulation by m6A and protein interactions.