PUMILIO competes with AUF1 to control DICER1 RNA levels and miRNA processing

Area of Science:

• Molecular Biology
• Genetics
• Cancer Biology

Background:

• DICER1 syndrome is a hereditary cancer predisposition disorder.
• Mutations in DICER1 disrupt microRNA (miRNA) processing, impacting cellular homeostasis and tumor development.
• Understanding these mutations offers insights into novel regulatory mechanisms.

Purpose of the Study:

• To analyze a pathogenic DICER1 syndrome allele located in the DICER1 3' untranslated region (3'UTR).
• To investigate the molecular consequences of this specific allele on DICER1 mRNA regulation.
• To elucidate the role of post-transcriptional regulation in DICER1 levels.

Main Methods:

• Analysis of the rs1252940486 DICER1 allele.
• Investigating the interaction between the DICER1 3'UTR and RNA binding proteins.
• Assessing DICER1 mRNA and protein levels.
• Evaluating miRNA network alterations.

Main Results:

• The rs1252940486 allele abolishes the interaction between the DICER1 3'UTR and the PUMILIO RNA binding protein.
• This disruption leads to AUF1-mediated degradation of DICER1 mRNA.
• A significant decrease in DICER1 mRNA and protein levels was observed.
• Widespread reprogramming of miRNA networks occurred due to diminished DICER1 levels.

Conclusions:

• The rs1252940486 DICER1 allele significantly impacts DICER1 mRNA stability through disrupted PUMILIO binding and enhanced AUF1 degradation.
• This single mutation profoundly affects miRNA processing and cellular regulation, contributing to DICER1 syndrome.
• The study highlights critical post-transcriptional regulatory events controlling DICER1 levels and their role in disease pathogenesis.