PAXT-1 promotes XRN2 activity by stabilizing it through a conserved domain.
XRN2 is an essential eukaryotic exoribonuclease that processes and degrades various substrates. Here we identify the previously uncharacterized protein R05D11.6/PAXT-1 as a subunit of an XRN2 complex in C. elegans. Targeted paxt-1 inactivation through TALEN-mediated genome editing reduces XRN2 levels, decreases miRNA turnover activity, and results in worm death, which can be averted by overexpressing xrn-2. Hence, stabilization of XRN2 is a major function of PAXT-1. A truncated PAXT-1 protein retaining a predicted domain of unknown function (DUF3469) suffices to restore viability to paxt-1 mutant animals, elevates XRN2 levels, and binds to XRN2. This domain occurs in additional metazoan proteins and mediates interaction of human CDKN2AIP/CARF and NKRF/NRF with XRN2. Thus, we have identified a bona fide XRN2-binding domain (XTBD) that can link different proteins, and possibly functionalities, to XRN2.
Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
Takashi S
TS
Miki
Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; University of Basel, Petersplatz 1, 4003 Basel, Switzerland.
Hannes
H
Richter
Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; University of Basel, Petersplatz 1, 4003 Basel, Switzerland.
Stefan
S
Rüegger
Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland. Electronic address: helge.grosshans@fmi.ch.
Helge
H
Großhans
D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D001665:Binding Sites; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017124:Conserved Sequence; D004268:DNA-Binding Proteins; D005095:Exoribonucleases / Q000378:metabolism; D055786:Gene Knockout Techniques; D006801:Humans; D017434:Protein Structure, Tertiary; D020871:RNA Stability; D016601:RNA-Binding Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
D051017:Apoptosis Regulatory Proteins; C539004:CDKN2AIP protein, human; C486724:CaRF protein, human; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C111027:NKRF protein, human; C000608560:PAXT-1 protein, C elegans; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D005095:Exoribonucleases; C120903:XRN2 protein, human