IMP1 KH1 and KH2 domains create a structural platform with unique RNA recognition and re-modelling properties

Robert Dagil, Neil J. Ball, Roksana W. Ogrodowicz, Fruzsina Hobor, Andrew G. Purkiss, Geoff Kelly, Stephen R. Martin, Ian A. Taylor, Andres Ramos*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

16 Citations (Scopus)
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Abstract

IGF2 mRNA-binding protein 1 (IMP1) is a key regulator of messenger RNA (mRNA) metabolism and transport in organismal development and, in cancer, its mis-regulation is an important component of tumour metastasis. IMP1 function relies on the recognition of a diverse set of mRNA targets that is mediated by the combinatorial action of multiple RNAbinding domains. Here, we dissect the structure and RNA-binding properties of two key RNA-binding domains of IMP1, KH1 and KH2, and we build a kinetic model for the recognition of RNA targets. Our data and model explain how the two domains are organized as an intermolecular pseudo-dimer and that the important role they play in mRNA target recognition is underpinned by the high RNA-binding affinity and fast kinetics of this KH1KH2-RNA recognition unit. Importantly, the high-affinity RNA-binding by KH1KH2 is achieved by an inter-domain coupling 50- fold stronger than that existing in a second pseudodimer in the protein, KH3KH4. The presence of this strong coupling supports a role of RNA re-modelling in IMP1 recognition of known cancer targets.

Original languageEnglish
JournalNucleic Acids Research
Volume47
Issue number8
Pages (from-to)4334-4348
Number of pages15
ISSN0305-1048
DOIs
Publication statusPublished - 2019

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