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Full-length NF-κB repressing factor contains an XRN2 binding domain.

Published version
Peer-reviewed

Type

Article

Change log

Authors

Alexandrova, Jana 
Piñeiro, David 
Jukes-Jones, Rebekah 
Mordue, Ryan 
Stoneley, Mark 

Abstract

NF-κB repressing factor (NKRF) was recently identified as an RNA binding protein that together with its associated proteins, the 5'-3' exonuclease XRN2 and the helicase DHX15, is required to process the precursor ribosomal RNA. XRN2 is a multi-functional ribonuclease that is also involved in processing mRNAs, tRNAs and lncRNAs. The activity and stability of XRN2 are controlled by its binding partners, PAXT-1, CDKN2AIP and CDKN2AIPNL. In each case, these proteins interact with XRN2 via an XRN2 binding domain (XTBD), the structure and mode of action of which is highly conserved. Rather surprisingly, although NKRF interacts directly with XRN2, it was not predicted to contain such a domain, and NKRF's interaction with XRN2 was therefore unexplained. We have identified an alternative upstream AUG start codon within the transcript that encodes NKRF and demonstrate that the full-length form of NKRF contains an XTBD that is conserved across species. Our data suggest that NKRF is tethered in the nucleolus by binding directly to rRNA and that the XTBD in the N-terminal extension of NKRF is essential for the retention of XRN2 in this sub-organelle. Thus, we propose NKRF regulates the early steps of pre-rRNA processing during ribosome biogenesis by controlling the spatial distribution of XRN2 and our data provide further support for the XTBD as an XRN2 interacting motif.

Description

Keywords

RNA-binding proteins, XRN2, XTBD, protein synthesis, ribosome biogenesis, Amino Acid Sequence, Cell Nucleolus, Exoribonucleases, HeLa Cells, Humans, Protein Binding, Protein Interaction Domains and Motifs, RNA Precursors, RNA Processing, Post-Transcriptional, RNA, Ribosomal, Repressor Proteins, Sequence Homology

Journal Title

Biochem J

Conference Name

Journal ISSN

0264-6021
1470-8728

Volume Title

477

Publisher

Portland Press Ltd.