InterPro domain: IPR039727

This entry includes SERRATE (SE) from plants and its homologues, Ars2, from animals and Pir2 from Schizosaccharomyces pombe [ 1 ]. These proteins play a role in nuclear RNA metabolism. They interact with the nuclear cap-binding complex (CBC) and mediates interactions with diverse RNA processing and transport machineries in a transcript-dependent manner. Interestingly, the plant SERRATE does not have the RNA recognition motif (RRM) domain found in metazoans and S. pombe [ 2 ].

In Arabidopsis, SE acts as a mediator between the cap-binding complex (CBC) and both the pre-mRNA splicing and primary microRNAs (miRNAs) processing machinery [ 3 , 4 ]. Drosophila Ars2 has been shown to regulate both miRNA- and siRNA- dependent silencing and suppress RNA virus infection [ 5 ].

The structure of the human Ars2 has been determined [ 6 ].

Ars2 and Pir2 are found in the nuclear RNA silencing (NURS) complex. The NURS complex also includes the Red1, Mtl1, Red5, Rmn1, and Iss10 proteins and associates with several other complexes that are involved in either signaling or mediating RNA silencing [ 6 ].

1. Post-transcriptional regulation of meiotic genes by a nuclear RNA silencing complex. RNA 20, 867-81
2. Structural analysis of human ARS2 as a platform for co-transcriptional RNA sorting. Nat Commun 9, 1701
3. Dual roles of the nuclear cap-binding complex and SERRATE in pre-mRNA splicing and microRNA processing in Arabidopsis thaliana. Proc. Natl. Acad. Sci. U.S.A. 105, 8795-800
4. Splicing and dicing with a SERRATEd edge. Proc. Natl. Acad. Sci. U.S.A. 105, 8489-90
5. Ars2 regulates both miRNA- and siRNA- dependent silencing and suppresses RNA virus infection in Drosophila. Cell 138, 340-51