CPEB1 coordinates alternative 3'-UTR formation with translational regulation

Area of Science:

• Molecular Biology
• RNA Biology
• Cancer Biology

Background:

• Over half of mammalian genes produce multiple messenger RNA (mRNA) isoforms with varying 3' untranslated regions (3' UTRs).
• These 3' UTRs contain regulatory sequences crucial for processes like cell proliferation and are often implicated in cancer.
• The mechanisms governing alternative 3' UTR processing remain largely undefined.

Purpose of the Study:

• To investigate the role of cytoplasmic polyadenylation element binding protein 1 (CPEB1) in regulating alternative 3' UTR processing.
• To elucidate how CPEB1 coordinates mRNA translation with 3' UTR processing.

Main Methods:

• Investigated CPEB1's subcellular localization (nucleus and cytoplasm).
• Analyzed CPEB1's interaction with splicing factors and pre-mRNAs.
• Assessed the impact of CPEB1 on alternative polyadenylation and alternative splicing.

Main Results:

• CPEB1 shuttles to the nucleus and co-localizes with splicing factors.
• CPEB1 mediates the shortening of hundreds of mRNA 3' UTRs, affecting cytoplasmic translation efficiency.
• CPEB1 binding to pre-mRNAs influences alternative polyadenylation site usage and alternative splicing by inhibiting U2AF65 recruitment.
• CPEB1-mediated 3' UTR shortening is correlated with increased cell proliferation and tumorigenesis.

Conclusions:

• CPEB1 possesses a novel function in controlling alternative 3' UTR processing.
• CPEB1 integrates 3' UTR processing with mRNA translation regulation through its dual nuclear and cytoplasmic activities.
• CPEB1's role in 3' UTR processing has implications for understanding cell proliferation and cancer development.