Active Genetics & Molecular Biology Cells, Biochemistry & Physiology

The molecular basis of mRNA 3ʹ-end processing

Funder Wellcome Charity-funded
Recipient organisation MRC Laboratory of Molecular Biology
Funding £2.4M
Period Jan 2023 — Dec 2030

In plain English

AI plain-English summary

Every human cell relies on a molecular machine called CPF to snip newly made messenger RNAs and stitch a poly(A) tail onto the cut end — a tail that determines whether the mRNA gets exported from the nucleus, translated into protein, or destroyed. Without this precise 3ʹ-end processing, gene expression breaks down. The CPF complex must coordinate three enzymatic activities — cutting, tail-building, and phosphate removal — while also talking to the transcription machinery that made the RNA. How it manages this choreography at the atomic level is unknown. This project will use cryo-electron microscopy, X-ray crystallography, NMR, and single-molecule techniques to map CPF’s structure, its sequence preferences, and the conformational changes that drive its function. The work is fundamental science: it asks how a core piece of cellular machinery works, not how to fix a disease or build a device. But the payoff is real. Misregulation of 3ʹ-end processing is linked to cancers and developmental disorders. A molecular blueprint of CPF could eventually reveal why those links exist and point toward where to intervene — even if that application remains years away.

View original technical description
Poly-adenosine (poly(A)) tails are found at the 3'-end of almost every eukaryotic mRNA and play essential roles in regulating gene expression. Poly(A) tails are required for export of mRNAs from the nucleus, for efficient translation and for mRNA stability. They are added by the evolutionarily- conserved cleavage and polyadenylation factor (CPF/CPSF), a megadalton multi- subunit complex that cleaves pre-mRNAs, adds a poly(A) tail of specified length and promotes transcription termination. The activities of CPF (endonuclease, polymerase and phosphatase) must be intimately coupled with each other and with transcription but the molecular basis for this remains unknown. In this proposal, I will use an integrated approach to obtain a molecular understanding of eukaryotic mRNA 3'-end processing. Specifically, I aim to: 1) Determine the sequence specificity of the 3'-end processing machinery; 2) Understand the molecular basis of pre-mRNA recognition, cleavage and polyadenylation; 3) Understand how dynamics and conformational changes contribute to CPF activities; 4) Determine how CPF is coupled to transcription. In addition to cryoEM, X-ray crystallography, biochemical reconstitutions and functional studies, we will employ NMR and single-molecule studies to investigate the dynamics of this process. Together, this will define the molecular basis of mRNA 3'-end processing.

View the original record at the funder ↗

Researchers

Lori Passmore (EPMC Awardee)

Related Research

Grants with similar aims, by meaning.

Structural and biochemical studies on mRNA 3’-end processing and transcription termination in fission yeast
The polyA machinery: Elucidating the molecular mechanisms of mRNA polyadenylation, deadenylation and RNA recognition
The beginning and end of poly(A) tails
Regulation of gene expression by mechanisms that target alternatively cleaved and polyadenylated mRNA isoforms
Up-frameshift protein interactions in translation termination and nonsense-mediated mRNA decay

Original classification

Discovery Award

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